Browsing by Subject "Diabetes mellitus"
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- ItemOpen AccessAccess to diagnostic tests and essential medicines for cardiovascular diseases and diabetes care: cost, availability and affordability in the west region of Cameroon(Public Library of Science, 2014) Jingi, Ahmadou M; Noubiap, Jean Jacques N; Onana, Arnold Ewane; Nansseu, Jobert Richie N; Wang, Binhuan; Kingue, Samuel; Kengne, André PascalObjective: To assess the availability and affordability of medicines and routine tests for cardiovascular disease (CVD) and diabetes in the West region of Cameroon, a low-income setting. METHODS: A survey was conducted on the availability and cost of twelve routine tests and twenty medicines for CVD and diabetes in eight health districts (four urban and four rural) covering over 60% of the population of the region (1.8 million). We analyzed the percentage of tests and medicines available, the median price against the international reference price (median price ratio) for the medicines, and affordability in terms of the number of days' wages it would cost the lowest-paid unskilled government worker for initial investigation tests and procurement for one month of treatment. RESULTS: The availability of tests varied between 10% for the ECG to 100% for the fasting blood sugar. The average cost for the initial investigation using the minimum tests cost 29.76 days' wages. The availability of medicines varied from 36.4% to 59.1% in urban and from 9.1% to 50% in rural settings. Only metformin and benzathine-benzylpenicilline had a median price ratio of ≤1.5, with statins being largely unaffordable (at least 30.51 days' wages). One month of combination treatment for coronary heart disease costs at least 40.87 days' wages. CONCLUSION: The investigation and management of patients with medium-to-high cardiovascular risk remains largely unavailable and unaffordable in this setting. An effective non-communicable disease program should lay emphasis on primary prevention, and improve affordable access to essential medicines in public outlets.
- ItemOpen AccessAnaemia, haemoglobin level and cause-specific mortality in people with and without diabetes(Public Library of Science, 2012) Kengne, Andre Pascal; Czernichow, Sébastien; Hamer, Mark; Batty, G David; Stamatakis, EmmanuelBACKGROUND: Both anaemia and cardiovascular disease (CVD) are common in people with diabetes. While individually both characteristics are known to raise mortality risk, their combined influence has yet to be quantified. In this pooling project, we examined the combined impact of baseline haemoglobin levels and existing CVD on all-cause and CVD mortality in people with diabetes. We draw comparison of these effects with those apparent in diabetes-free individuals. Methods/Principal FINDINGS: A combined analyses of 7 UK population-based cohorts resulted in 26,480 study members. There were 946 participants with physician-diagnosed diabetes, 2227 with anaemia [haemoglobin<13 g/dl (men) or <12 (women)], 2592 with existing CVD (stroke, ischaemic heart disease), and 21,396 with none of the conditions. Across diabetes and anaemia subgroups, and using diabetes-free, non-anaemic participants as the referent group, the adjusted hazard ratios (HR) were 1.46 (95% CI: 1.30-1.63) for anaemia, 1.67 (1.45-1.92) for diabetes, and 2.10 (1.55-2.85) for diabetes and anaemia combined. Across combined diabetes, anaemia and CVD subgroups, and compared with non-anaemic, diabetes-free and CVD-free participants, HR (95% CI) for all-cause mortality were 1.49 (1.32-1.69) anaemia, 1.60 (1.46-1.76) for existing CVD, and 1.66 (1.39-1.97) for diabetes alone. Equivalents were 2.13 (1.48-3.07) for anaemia and diabetes, 2.68 (2.14-3.36) for diabetes and existing CVD, and 3.25 (1.88-5.62) for the three combined. Patterns were similar for CVD mortality. Conclusions/Significance Individually, anaemia and CVD confer similar mortality risks in people with diabetes, and are excessively fatal in combination. Screening for anaemia would identify vulnerable diabetic patients whose outcomes can potentially be improved.
- ItemOpen AccessBaseline predictors of mortality among predominantly rural-dwelling end-stage renal disease patients on chronic dialysis therapies in Limpopo, South Africa(Public Library of Science, 2016) Isla, Ramon A Tamayo; Ameh, Oluwatoyin I; Mapiye, Darlington; Swanepoel, Charles R; Bello, Aminu K; Ratsela, Andrew R; Okpechi, Ikechi GBACKGROUND: Dialysis therapy for end-stage renal disease (ESRD) continues to be the readily available renal replacement option in developing countries. While the impact of rural/remote dwelling on mortality among dialysis patients in developed countries is known, it remains to be defined in sub-Saharan Africa. METHODS: A single-center database of end-stage renal disease patients on chronic dialysis therapies treated between 2007 and 2014 at the Polokwane Kidney and Dialysis Centre (PKDC) of the Pietersburg Provincial Hospital, Limpopo South Africa, was retrospectively reviewed. All-cause, cardiovascular, and infection-related mortalities were assessed and associated baseline predictors determined. RESULTS: Of the 340 patients reviewed, 52.1% were male, 92.9% were black Africans, 1.8% were positive for the human immunodeficiency virus (HIV), and 87.5% were rural dwellers. The average distance travelled to the dialysis centre was 112.3 ± 73.4 Km while 67.6% of patients lived in formal housing. Estimated glomerular filtration rate (eGFR) at dialysis initiation was 7.1 ± 3.7 mls/min while hemodialysis (HD) was the predominant modality offered (57.1%). Ninety-two (92) deaths were recorded over the duration of follow-up with the majority (34.8%) of deaths arising from infection-related causes. Continuous ambulatory peritoneal dialysis (CAPD) was a significant predictor of all-cause mortality (HR: 1.62, CI: 1.07-2.46) and infection-related mortality (HR: 2.27, CI: 1.13-4.60). On multivariable cox regression, CAPD remained a significant predictor of all-cause mortality (HR: 2.00, CI: 1.29-3.10) while the risk of death among CAPD patients was also significantly modified by diabetes mellitus (DM) status (HR: 4.99, CI: 2.13-11.71). CONCLUSION: CAPD among predominantly rural dwelling patients in the Limpopo province of South Africa is associated with an increased risk of death from all-causes and infection-related causes.
- ItemOpen AccessBlood pressure gradients and cardiovascular risk factors in urban and rural populations in Abia State South Eastern Nigeria using the WHO STEPwise approach(Public Library of Science, 2013) Okpechi, Ikechi Gareth; Chukwuonye, Innocent Ijezie; Tiffin, Nicki; Madukwe, Okechukwu Ojoemelam; Onyeonoro, Ugochukwu Uchenna; Umeizudike, Theophilus Ifeanyichukwu; Ogah, Okechukwu SamuelBACKGROUND: Developing countries of sub-Saharan Africa (SSA) face a double burden of non-communicable diseases (NCDs) and communicable diseases. As high blood pressure (BP) is a common global cardiovascular (CV) disorder associated with high morbidity and mortality, the relationship between gradients of BP and other CV risk factors was assessed in Abia State, Nigeria. METHODS: Using the WHO STEPwise approach to surveillance of chronic disease risk factors, we conducted a population-based cross-sectional survey in Abia state, Nigeria from August 2011 to March 2012. Data collected at various steps included: demographic and behavioral risk factors (Step 1); BP and anthropometric measurements (Step 2), and fasting blood cholesterol and glucose (Step 3). RESULTS: Of the 2983 subjects with complete data for analysis, 52.1% were females and 53.2% were rural dwellers. Overall, the distribution of selected CV disease risk factors was diabetes (3.6%), hypertension (31.4%), cigarette smoking (13.3%), use of smokeless tobacco (4.8%), physical inactivity (64.2%) and being overweight or obese (33.7%). Presence of hypertension, excessive intake of alcohol, smoking (cigarette and smokeless tobacco) and physical inactivity occurred more frequently in males than in females (p<0.05); while low income, lack of any formal education and use of smokeless tobacco were seen more frequently in rural dwellers than in those living in urban areas (p<0.05). The frequency of selected CV risk factors increased as BP was graded from optimal, normal to hypertension; and high BP correlated with age, gender, smokeless tobacco, overweight or obesity, annual income and level of education. CONCLUSION: Given the high prevalence of hypertension in this part of Nigeria, there is an urgent need to focus on the reduction of preventable CV risk factors we have observed to be associated with hypertension, in order to effectively reduce the burden of NCDs in Africa.
- ItemOpen AccessCardio-thoracic ratio is stable, reproducible and has potential as a screening tool for HIV-1 related cardiac disorders in resource poor settings(Public Library of Science, 2016) Esmail, Hanif; Oni, Tolu; Thienemann, Friedrich; Omar-Davies, Nashreen; Wilkinson, Robert J; Ntsekhe, MpikoBACKGROUND: Cardiovascular disorders are common in HIV-1 infected persons in Africa and presentation is often insidious. Development of screening algorithms for cardiovascular disorders appropriate to a resource-constrained setting could facilitate timely referral. Cardiothoracic ratio (CTR) on chest radiograph (CXR) has been suggested as a potential screening tool but little is known about its reproducibility and stability. Our primary aim was to evaluate the stability and the inter-observer variability of CTR in HIV-1 infected outpatients. We further evaluated the prevalence of cardiomegaly (CTR≥0.5) and its relationship with other risk factors in this population. METHODOLOGY: HIV-1 infected participants were identified during screening for a tuberculosis vaccine trial in Khayelitsha, South Africa between August 2011 and April 2012. Participants had a digital posterior-anterior CXR performed as well as history, examination and baseline observations. CXRs were viewed using OsiriX software and CTR calculated using digital callipers. RESULTS: 450 HIV-1-infected adults were evaluated, median age 34 years (IQR 30-40) with a CD4 count 566/mm 3 (IQR 443-724), 70% on antiretroviral therapy (ART). The prevalence of cardiomegaly was 12.7% (95% C.I. 9.6%-15.8%). CTR was calculated by a 2 nd reader for 113 participants, measurements were highly correlated r = 0.95 (95% C.I. 0.93-0.97) and agreement of cardiomegaly substantial κ = 0.78 (95% C.I 0.61-0.95). CXR were repeated in 51 participants at 4-12 weeks, CTR measurements between the 2 time points were highly correlated r = 0.77 (95% C.I 0.68-0.88) and agreement of cardiomegaly excellent κ = 0.92 (95% C.I. 0.77-1). Participants with cardiomegaly had a higher median BMI (31.3; IQR 27.4-37.4) versus 26.9; IQR 23.2-32.4); p<0.0001) and median systolic blood pressure (130; IQR 121-141 versus 125; IQR 117-135; p = 0.01). CONCLUSION: CTR is a robust measurement, stable over time with substantial inter-observer agreement. A prospective study evaluating utility of CXR to identify cardiovascular disorder in this population is warranted.
- ItemOpen AccessCardiovascular risk factors in patients with Addison's disease: a comparative study of South African and Swedish patients(Public Library of Science, 2014) Ross, Ian Louis; Bergthorsdottir, Ragnhildur; Levitt, Naomi; Dave, Joel Alex; Schatz, Desmond; Marais, David; Johannsson, GudmundurBACKGROUND: Patients with Addison's disease (AD) in Scandinavia have an increased risk for premature death due to cardiovascular disease (CVD). Serum lipids are important risk factors for CVD and vascular mortality. Replacement doses of hydrocortisone have historically been higher in Sweden than South Africa. The primary aim was to study the lipid profiles in a large group of patients with AD with the hypothesis that the lipid profile in patients in Sweden would be worse than in South Africa. METHODS: In a cross-sectional study, 110 patients with AD (55 from South Africa, 55 from Sweden) matched for age, gender, ethnicity and BMI were studied. Anthropometric measures, blood pressure, lipids, highly sensitive C-reactive protein (hs-CRP) and adiponectin were studied. RESULTS: All patients were Caucasian and the majority were women N = 36 (65.5%). Mean (standard deviation; SD) ages of the Swedish and South African patients were 52.9 (13.0) and 52.6 (14.4) years and BMI 25.3 (3.2) and 25.8 (4.1) kg/m 2 , respectively. The mean total daily hydrocortisone dose was greater in the Swedish patients than the South African patients, [33.0 (8.1) versus 24.3 (8.0) mg; p<0.0001]. South African patients had higher median (interquartilerange; IQR) triglycerides (TG) [1.59 (1.1-2.46) versus 0.96 (0.74-1.6) mmol/l; p<0.001], total cholesterol (TC) [6.02(1.50) versus 5.13 (0.87) mmol/l; p<0.001], LDL-C [4.43 (1.44) versus 2.75 (0.80) mmol/l; p<0.001] and median hs-CRP [2.15 (0.93-5.45) versus 0.99 (0.57-2.10) mg/L; p<0.003] and lower HDL-C [0.80 (0.40) versus 1.86 (0.46) mmol/l; p<0.001] than the Swedish patients. Approximately 20% of the patients in both cohorts had hypertension and diabetes mellitus. CONCLUSIONS: South African patients with AD have worse lipid profiles and higher hs-CRP compared to their matched Swedish patients, despite lower doses of hydrocortisone. It is uncertain at this time whether these are due to genetic or environmental factors.
- ItemOpen AccessChromosome 9p21 SNPs associated with multiple disease phenotypes correlate with ANRIL expression(Public Library of Science, 2010) Cunnington, Michael S; Koref, Mauro Santibanez; Mayosi, Bongani M; Burn, John; Keavney, BernardAuthor Summary Genetic variants on chromosome 9p21 have been associated with several important diseases including coronary artery disease, diabetes, and multiple cancers. Most of the risk variants in this region do not alter any protein sequence and are therefore likely to act by influencing the expression of nearby genes. We investigated whether chromosome 9p21 variants are correlated with expression of the three nearest genes ( CDKN2A , CDKN2B , and ANRIL ) which might mediate the association with disease. Using two different techniques to study effects on expression in blood from two separate populations of healthy volunteers, we show that variants associated with disease are all correlated with ANRIL expression, but associations with the other two genes are weaker and less consistent. Multiple genetic variants are independently associated with expression of all three genes. Although total expression levels of CDKN2A , CDKN2B , and ANRIL are positively correlated, individual genetic variants influence ANRIL and CDKN2B expression in opposite directions, suggesting a possible role of ANRIL in CDKN2B regulation. Our study suggests that modulation of ANRIL expression mediates susceptibility to several important human diseases.
- ItemOpen AccessCoincidence of diabetes mellitus and hypertension in a semi-urban Cameroonian population: a cross-sectional study(BioMed Central Ltd, 2014) Katte, Jean-Claude; Dzudie, Anastase; Sobngwi, Eugene; Mbong, Eta; Fetse, Gerard; Kouam, Charles; Kengne, Andre-PascalBACKGROUND: Hypertension and diabetes mellitus are increasingly common in population within Africa. We determined the rate of coincident diabetes and hypertension and assessed the levels of co-awareness, treatment and control in a semi-urban population in Cameroon. METHODS: A total of 1702 adults (967 women) self-selected from the community were consecutively recruited in Bafoussam (West region of Cameroon) during November 2012. Existing diabetes and hypertension and treatments were investigated and blood pressure and fasting blood glucose measured. Multinomial logistic regressions models were used to investigate the determinants of prevalent diabetes and hypertension. RESULTS: Age-standardized prevalence rates (95% confidence intervals) men vs. women were 40.4% (34.7 to 46.1) and 23.8% (20.4 to 27.2) for hypertension alone; 3.3% (1.5 to 5.1) and 5.6% (3.5 to 7.7) for diabetes alone; and 3.9% (2.6 to 5.2) and 5.0% (3.5 to 6.5) for hypertension and diabetes. The age-standardized awareness, treatment and control rates for hypertension alone were 6.5%, 86.4% and 37.2% for men, and 24.3%, 52.1% and 51.6% in women. Equivalent figures for diabetes alone were 35.4%, 65.6% and 23.1% in men and 26.4%, 75.5% and 33.7% in women; and those for hypertension and diabetes were 86.6%, 3.3% and 0% in men, and 74.7%, 22.6% and 0% in women. Sex, age and adiposity were the main determinants of the three conditions. CONCLUSIONS: Coincident diabetes and hypertension is as high as diabetes alone in this population, driven by sex, age and adiposity. Awareness, treatment and control remain unacceptably low.
- ItemOpen AccessDiffering patterns of overweight and obesity among black men and women in Cape Town: the CRIBSA study(Public Library of Science, 2014) Peer, Nasheeta; Lombard, Carl; Steyn, Krisela; Gwebushe, Nomonde; Levitt, NaomiObjectives To ascertain the prevalence and determinants of overweight/obesity in the 25-74-year-old urban black population of Cape Town and examine the changes between 1990 and 2008/09. METHODS: In 2008/09, a representative cross-sectional sample, stratified for age and sex, was randomly selected from the same townships sampled in 1990. Data were collected by questionnaires, clinical measurements and biochemical analyses. Gender-specific linear regression models evaluated the associations with overweight/obesity. RESULTS: There were 1099 participants, 392 men and 707 women (response rate 86%) in 2008/09. Mean body mass index (BMI) and waist circumference (WC) were 23.7 kg/m 2 (95% confidence interval (CI): 23.1-24.2) and 84.2 cm (95% CI: 82.8-85.6) in men, and 33.0 kg/m 2 (95% CI: 32.3-33.7) and 96.8 cm (95% CI: 95.5-98.1) in women. Prevalence of BMI ≥25 kg/m 2 and raised WC were 28.9% (95% CI: 24.1-34.3) and 20.1% (95% CI: 15.9-24.9) in men, and 82.8% (95% CI: 79.3-85.9) and 86.0% (95% CI: 82.9-88.6) in women. Among 25-64-year-olds, BMI ≥25 kg/m 2 decreased between 1990 (37.3%, 95% CI: 31.7-43.1) and 2008/09 (27.7%, 95% CI: 22.7-33.4) in men but increased from 72.7% (95% CI: 67.6-77.2) to 82.6% (95% CI: 78.8-85.8) in women. In the regression models for men and women, higher BMI was directly associated with increasing age, wealth, hypertension and diabetes but inversely related to daily smoking. Also significantly associated with rising BMI were raised low-density lipoprotein cholesterol and being employed compared to unemployed in men, and having >7 years of education in women. CONCLUSIONS: Overweight/obesity, particularly in urban black women, requires urgent action because of the associations with cardiovascular disease risk factors and their serious consequences.
- ItemOpen AccessEffects of different missing data imputation techniques on the performance of undiagnosed diabetes risk prediction models in a mixed-ancestry population of South Africa(Public Library of Science, 2015) Masconi, Katya L; Matsha, Tandi E; Erasmus, Rajiv T; Kengne, Andre PBACKGROUND: Imputation techniques used to handle missing data are based on the principle of replacement. It is widely advocated that multiple imputation is superior to other imputation methods, however studies have suggested that simple methods for filling missing data can be just as accurate as complex methods. The objective of this study was to implement a number of simple and more complex imputation methods, and assess the effect of these techniques on the performance of undiagnosed diabetes risk prediction models during external validation. METHODS: Data from the Cape Town Bellville-South cohort served as the basis for this study. Imputation methods and models were identified via recent systematic reviews. Models’ discrimination was assessed and compared using C-statistic and non-parametric methods, before and after recalibration through simple intercept adjustment. RESULTS: The study sample consisted of 1256 individuals, of whom 173 were excluded due to previously diagnosed diabetes. Of the final 1083 individuals, 329 (30.4%) had missing data. Family history had the highest proportion of missing data (25%). Imputation of the outcome, undiagnosed diabetes, was highest in stochastic regression imputation (163 individuals). Overall, deletion resulted in the lowest model performances while simple imputation yielded the highest C-statistic for the Cambridge Diabetes Risk model, Kuwaiti Risk model, Omani Diabetes Risk model and Rotterdam Predictive model. Multiple imputation only yielded the highest C-statistic for the Rotterdam Predictive model, which were matched by simpler imputation methods. CONCLUSIONS: Deletion was confirmed as a poor technique for handling missing data. However, despite the emphasized disadvantages of simpler imputation methods, this study showed that implementing these methods results in similar predictive utility for undiagnosed diabetes when compared to multiple imputation.
- ItemOpen AccessA high burden of hypertension in the urban black population of Cape Town: the cardiovascular risk in Black South Africans (CRIBSA) study(Public Library of Science, 2013) Peer, Nasheeta; Steyn, Krisela; Lombard, Carl; Gwebushe, Nomonde; Levitt, NaomiObjective To determine the prevalence, associations and management of hypertension in the 25-74-year-old urban black population of Cape Town and examine the change between 1990 and 2008/09 in 25-64-year-olds. METHODS: In 2008/09, a representative cross-sectional sample, stratified for age and sex, was randomly selected from the same townships sampled in 1990. Cardiovascular disease risk factors were determined by administered questionnaires, clinical measurements and fasting biochemical analyses. Logistic regression models evaluated the associations with hypertension. RESULTS: There were 1099 participants, 392 men and 707 women (response rate 86%) in 2008/09. Age-standardised hypertension prevalence was 38.9% (95% confidence interval (CI): 35.6-42.3) with similar rates in men and women. Among 25-64-year-olds, hypertension prevalence was significantly higher in 2008/09 (35.6%, 95% CI: 32.3-39.0) than in 1990 (21.6%, 95% CI: 18.6-24.9). In 2008/09, hypertension odds increased with older age, family history of hypertension, higher body mass index, problematic alcohol intake, physical inactivity and urbanisation. Among hypertensive participants, significantly more women than men were detected (69.5% vs. 32.7%), treated (55.7% vs. 21.9%) and controlled (32.4% vs. 10.4%) in 2008/09. There were minimal changes from 1990 except for improved control in 25-64-year-old women (1990∶14.1% vs. 2008/09∶31.5%). CONCLUSIONS: The high and rising hypertension burden in this population, its association with modifiable risk factors and the sub-optimal care provided highlight the urgent need to prioritise hypertension management. Innovative solutions with efficient and cost-effective healthcare delivery as well as population-based strategies are required.
- ItemOpen AccessLinkage to HIV, TB and non-communicable disease care from a mobile testing unit in Cape Town, South Africa(Public Library of Science, 2013) Govindasamy, Darshini; Kranzer, Katharina; van Schaik, Nienke; Noubary, Farzad; Wood, Robin; Walensky, Rochelle P; Freedberg, Kenneth A; Bassett, Ingrid V; Bekker, Linda-GailBACKGROUND: HIV counseling and testing may serve as an entry point for non-communicable disease screening. Objectives To determine the yield of newly-diagnosed HIV, tuberculosis (TB) symptoms, diabetes and hypertension, and to assess CD4 count testing, linkage to care as well as correlates of linkage and barriers to care from a mobile testing unit. METHODS: A mobile unit provided screening for HIV, TB symptoms, diabetes and hypertension in Cape Town, South Africa between March 2010 and September 2011. The yield of newly-diagnosed cases of these conditions was measured and clients were followed-up between January and November 2011 to assess linkage. Linkage to care was defined as accessing care within one, three or six months post-HIV diagnosis (dependent on CD4 count) and one month post-diagnosis for other conditions. Clinical and socio-demographic correlates of linkage to care were evaluated using Poisson regression and barriers to care were determined. RESULTS: Of 9,806 clients screened, the yield of new diagnoses was: HIV (5.5%), TB suspects (10.1%), diabetes (0.8%) and hypertension (58.1%). Linkage to care for HIV-infected clients, TB suspects, diabetics and hypertensives was: 51.3%, 56.7%, 74.1% and 50.0%. Only disclosure of HIV-positive status to family members or partners (RR=2.6, 95% CI: 1.04-6.3, p =0.04) was independently associated with linkage to HIV care. The main barrier to care reported by all groups was lack of time to access a clinic. CONCLUSION: Screening for HIV, TB symptoms and hypertension at mobile units in South Africa has a high yield but inadequate linkage. After-hours and weekend clinics may overcome a major barrier to accessing care.
- ItemOpen AccessOleanolic acid: a novel cardioprotective agent that blunts hyperglycemia-induced contractile dysfunction(Public Library of Science, 2012) Mapanga, Rudo F; Rajamani, Uthra; Dlamini, Nonkululeko; Zungu-Edmondson, Makhosazane; Kelly-Laubscher, Roisin; Shafiullah, Mohammed; Wahab, Athiq; Hasan, Mohamed Y; Fahim, Mohamed A; Rondeau, PhilippeDiabetes constitutes a major health challenge. Since cardiovascular complications are common in diabetic patients this will further increase the overall burden of disease. Furthermore, stress-induced hyperglycemia in non-diabetic patients with acute myocardial infarction is associated with higher in-hospital mortality. Previous studies implicate oxidative stress, excessive flux through the hexosamine biosynthetic pathway (HBP) and a dysfunctional ubiquitin-proteasome system (UPS) as potential mediators of this process. Since oleanolic acid (OA; a clove extract) possesses antioxidant properties, we hypothesized that it attenuates acute and chronic hyperglycemia-mediated pathophysiologic molecular events (oxidative stress, apoptosis, HBP, UPS) and thereby improves contractile function in response to ischemia-reperfusion. We employed several experimental systems: 1) H9c2 cardiac myoblasts were exposed to 33 mM glucose for 48 hr vs. controls (5 mM glucose); and subsequently treated with two OA doses (20 and 50 µM) for 6 and 24 hr, respectively; 2) Isolated rat hearts were perfused ex vivo with Krebs-Henseleit buffer containing 33 mM glucose vs. controls (11 mM glucose) for 60 min, followed by 20 min global ischemia and 60 min reperfusion ± OA treatment; 3) In vivo coronary ligations were performed on streptozotocin treated rats ± OA administration during reperfusion; and 4) Effects of long-term OA treatment (2 weeks) on heart function was assessed in streptozotocin-treated rats. Our data demonstrate that OA treatment blunted high glucose-induced oxidative stress and apoptosis in heart cells. OA therapy also resulted in cardioprotection, i.e. for ex vivo and in vivo rat hearts exposed to ischemia-reperfusion under hyperglycemic conditions. In parallel, we found decreased oxidative stress, apoptosis, HBP flux and proteasomal activity following ischemia-reperfusion. Long-term OA treatment also improved heart function in streptozotocin-diabetic rats. These findings are promising since it may eventually result in novel therapeutic interventions to treat acute hyperglycemia (in non-diabetic patients) and diabetic patients with associated cardiovascular complications.
- ItemOpen AccessPolymorphisms in the non-muscle myosin heavy chain gene (MYH9) are associated with lower glomerular filtration rate in mixed ancestry diabetic subjects from South Africa(Public Library of Science, 2012) Matsha, Tandi Edith; Masconi, Katya; Yako, Yandiswa Yolanda; Hassan, Mogamat Shafick; Macharia, Muiriri; Erasmus, Rajiv Timothy; Kengne, Andre PascalObjective: Though single nucleotide polymorphisms (SNPs) in the non-muscle myosin gene (MYH9) have been reported to explain most of the excess risk of nondiabetic chronic kidney disease (CKD), in African-Americans, some studies have also shown associations with diabetic end-stage renal disease. We investigated the association of MYH9 SNPs with renal traits in a mixed-ancestry South African population prone to diabetes. Research Design and METHODS: Three SNPs known to be associated with CKD (rs4821480, rs5756152 and rs12107) were genotyped using Taqman assay in 716 adults (198 with diabetes) from the Bellville-South community, Cape Town. Glomerular filtration rate was estimated (eGFR) and urinary albumin/creatinine ratio (ACR) assessed. Multivariable regressions were used to relate the SNPs with renal traits. RESULTS: Mean age was 53.6 years, with the expected differences observed in characteristics by diabetic status. Significant associations were found between rs575152 and serum creatinine, and eGFR in the total population, and in diabetic participants (all p≤0.003), but not in non-diabetics (all p≥0.16), with significant interactions by diabetes status (interaction-p≤0.009). The association with ACR was borderline in diabetic participants (p = 0.05) and non-significant in non-diabetics (p = 0.85), with significant interaction (interaction p = 0.02). rs12107 was associated with fasting-, 2-hour glucose and HbA1c in diabetic participants only (interaction-p≤0.003), but not with renal traits. CONCLUSION: MYH9 SNPs were associated with renal traits only in diabetic participants in this population. Our findings and other studies suggest that MYH9 may have a broader genetic risk effect on kidney diseases.
- ItemOpen AccessReporting and handling of missing data in predictive research for prevalent undiagnosed type 2 diabetes mellitus: a systematic review(BioMed Central Ltd, 2015) Masconi, Katya L; Matsha, Tandi; Echouffo-Tcheugui, Justin; Erasmus, Rajiv; Kengne, AndreMissing values are common in health research and omitting participants with missing data often leads to loss of statistical power, biased estimates and, consequently, inaccurate inferences. We critically reviewed the challenges posed by missing data in medical research and approaches to address them. To achieve this more efficiently, these issues were analyzed and illustrated through a systematic review on the reporting of missing data and imputation methods (prediction of missing values through relationships within and between variables) undertaken in risk prediction studies of undiagnosed diabetes. Prevalent diabetes risk models were selected based on a recent comprehensive systematic review, supplemented by an updated search of English-language studies published between 1997 and 2014. Reporting of missing data has been limited in studies of prevalent diabetes prediction. Of the 48 articles identified, 62.5% (n=30) did not report any information on missing data or handling techniques. In 21 (43.8%) studies, researchers opted out of imputation, completing case-wise deletion of participants missing any predictor values. Although imputation methods are encouraged to handle missing data and ensure the accuracy of inferences, this has seldom been the case in studies of diabetes risk prediction. Hence, we elaborated on the various types and patterns of missing data, the limitations of case-wise deletion and state-of the-art methods of imputations and their challenges. This review highlights the inexperience or disregard of investigators of the effect of missing data in risk prediction research. Formal guidelines may enhance the reporting and appropriate handling of missing data in scientific journals.
- ItemOpen AccessRising diabetes prevalence among urban-dwelling black South Africans(Public Library of Science, 2012) Peer, Nasheeta; Steyn, Krisela; Lombard, Carl; Lambert, Estelle V; Vythilingum, Bavanisha; Levitt, Naomi SObjective: To examine the prevalence of and the association of psychosocial risk factors with diabetes in 25-74-year-old black Africans in Cape Town in 2008/09 and to compare the prevalence with a 1990 study. Research Design and METHODS: A randomly selected cross-sectional sample had oral glucose tolerance tests. The prevalence of diabetes (1998 WHO criteria), other cardiovascular risk factors and psychosocial measures, including sense of coherence (SOC), locus of control and adverse life events, were determined. The comparison of diabetes prevalence between this and a 1990 study used the 1985 WHO diabetes criteria. RESULTS: There were 1099 participants, 392 men and 707 women (response rate 86%). The age-standardised (SEGI) prevalence of diabetes was 13.1% (95% confidence interval (CI) 11.0-15.1), impaired glucose tolerance (IGT) 11.2% (9.2-13.1) and impaired fasting glycaemia 1.2% (0.6-1.9). Diabetes prevalence peaked in 65-74-year-olds (38.6%). Among diabetic participants, 57.9% were known and 38.6% treated. Using 1985 WHO criteria, age-standardised diabetes prevalence was higher by 53% in 2008/09 (12.2% (10.2-14.2)) compared to 1990 (8.0% (5.8-10.3)) and IGT by 67% (2008/09: 11.7% (9.8-13.7); 1990: 7.0% (4.9-9.1)). In women, older age (OR: 1.05, 95%CI: 1.03-1.08, p<0.001), diabetes family history (OR: 3.13, 95%CI: 1.92-5.12, p<0.001), higher BMI (OR: 1.44, 95%CI: 1.20-1.82, p = 0.001), better quality housing (OR: 2.08, 95%CI: 1.01-3.04, p = 0.047) and a lower SOC score (≤40) was positively associated with diabetes (OR: 2.57, 95%CI: 1.37-4.80, p = 0.003). Diabetes was not associated with the other psychosocial measures in women or with any psychosocial measure in men. Only older age (OR: 1.05, 95%CI: 1.02-1.08, p = 0.002) and higher BMI (OR: 1.10, 95%CI: 1.04-1.18, p = 0.003) were significantly associated with diabetes in men. CONCLUSIONS: The current high prevalence of diabetes in urban-dwelling South Africans, and the likelihood of further rises given the high rates of IGT and obesity, is concerning. Multi-facetted diabetes prevention strategies are essential to address this burden.
- ItemOpen AccessRisk models to predict chronic kidney disease and its progression: a systematic review(Public Library of Science, 2012) Echouffo-Tcheugui, Justin B; Kengne, Andre PA systematic review of risk prediction models conducted by Justin Echouffo-Tcheugui and Andre Kengne examines the evidence base for prediction of chronic kidney disease risk and its progression, and suitability of such models for clinical use.
- ItemOpen AccessStaff knowledge, attitudes and practices in public sector primary care of diabetes in Cape Town(1997)OBJECTIVE: To audit staff knowledge, attitudes and practices in the interest of improved public sector primary care for diabetics. DESIGN: External audit using face-to-face, private, questionnaire-based interviews. SETTING: Twelve public sector ambulatory health centres in Cape Town. SUBJECTS: Non-specialist, principal staff members (N = 35)-12 doctors, 10 primary health care nurses (PHCNs), 7 registered nurses (RNs) and 6 staff nurses (SNs). RESULTS: Staff members were long-standing employees (mean-doctors 6 years, PHCNs 8 years, RNs 5 years, SNs 12 years). Few had post-basic training (doctors 25%, PHCNs 20%, RNs 26%, SNs 83%). Knowledge of chronic diabetic complications was adequate, e.g. diabetic eye disease was mentioned by 100% of staff. There were gaps in knowledge of pathophysiology and of signs and symptoms of diabetic emergencies, e.g. < 33% knew control of hypertension to be important in the prevention of diabetic nephropathy. Knowledge of appropriate care of patients with hypoglycaemia (94% mentioned glucose administration) was better than that of hyperglycaemia (69% mentioned intravenous fluids). Problems were reported in inter-staff communication within (approximately 50%) and between (approximately 75%) disciplines by doctors, PHCNs and RNs. Staff/patient communication problems were reported by approximately 75% of staff. Solutions suggested by staff included meetings between staff members and with management, in-service training programmes and appointment systems for patients. Despite logistic, organisational and communication-related problems, most staff enjoy and believe in the value of their work. CONCLUSIONS: This study reveals deficiencies in in-service training with consequent gaps in knowledge and practice. Recommendations that would lead to improved quality of care and increased staff and patient satisfaction have been given.
- ItemOpen AccessStavudine toxicity in adult longer-term ART patients in Blantyre, Malawi(Public Library of Science, 2012) van Oosterhout, Joep J; Mallewa, Jane; Kaunda, Symon; Chagoma, Newton; Njalale, Yassin; Kampira, Elizabeth; Mukaka, Mavuto; Heyderman, Robert SBACKGROUND: Stavudine is an effective and inexpensive antiretroviral drug, but no longer recommended by WHO for first-line antiretroviral regimens in resource-limited settings due to toxicity concerns. Because of the high cost of alternative drugs, it has not been feasible to replace stavudine in most adults in the Malawi ART programme. We aimed to provide policy makers with a detailed picture of stavudine toxicities in Malawians on longer-term ART, in order to facilitate prioritization of stavudine replacement among other measures to improve the quality of ART programmes. METHODS: Prospective cohort of Malawian adults who had just completed one year of stavudine containing ART in an urban clinic, studying peripheral neuropathy, lipodystrophy, diabetes mellitus, high lactate syndromes, pancreatitis and dyslipidemia during 12 months follow up. Stavudine dosage was 30 mg irrespective of weight. Cox regression was used to determine associations with incident toxicities. RESULTS: 253 patients were enrolled, median age 36 years, 62.5% females. Prevalence rates (95%-confidence interval) of toxicities after one year on stavudine were: peripheral neuropathy 21.3% (16.5-26.9), lipodystrophy 14.7% (2.4-8.1), high lactate syndromes 0.0% (0-1.4), diabetes mellitus 0.8% (0-2.8), pancreatitis 0.0% (0-1.5). Incidence rates per 100 person-years (95%-confidence interval) during the second year on stavudine were: peripheral neuropathy 19.8 (14.3-26.6), lipodystrophy 11.4 (7.5-16.3), high lactate syndromes 2.1 (0.7-4.9), diabetes mellitus 0.4 (0.0-1.4), pancreatitis 0.0 (0.0-0.2). Prevalence of hypercholesterolemia and hypertriglyceridemia increased from 12.1% to 21.1% and from 29.5% to 37.6% respectively between 12 and 24 months. 5.5% stopped stavudine, 1.3% died and 4.0% defaulted during follow up. Higher age was an independent risk factor for incident peripheral neuropathy and lipodystrophy. CONCLUSION: Stavudine associated toxicities continued to accumulate during the second year of ART, especially peripheral neuropathy and lipodystrophy and more so at increasing age. Our findings support investments for replacing stavudine in first-line regimens in sub-Saharan Africa.
- ItemOpen Access"They just come, pick and go." The Acceptability of Integrated Medication Adherence Clubs for HIV and Non Communicable Disease (NCD) Patients in Kibera, Kenya(Public Library of Science, 2016) Venables, Emilie; Edwards, Jeffrey K; Baert, Saar; Etienne, William; Khabala, Kelly; Bygrave, HelenIntroduction The number of people on antiretroviral therapy (ART) for the long-term management of HIV in low- and middle-income countries (LMICs) is continuing to increase, along with the prevalence of Non-Communicable Diseases (NCDs). The need to provide large volumes of HIV patients with ART has led to significant adaptations in how medication is delivered, but access to NCD care remains limited in many contexts. Medication Adherence Clubs (MACs) were established in Kibera, Kenya to address the large numbers of patients requiring chronic HIV and/or NCD care. Stable NCD and HIV patients can now collect their chronic medication every three months through a club, rather than through individual clinic appointments. METHODOLOGY: We conducted a qualitative research study to assess patient and health-care worker perceptions and experiences of MACs in the urban informal settlement of Kibera, Kenya. A total of 106 patients (with HIV and/or other NCDs) and health-care workers were purposively sampled and included in the study. Ten focus groups and 19 in-depth interviews were conducted and 15 sessions of participant observation were carried out at the clinic where the MACs took place. Thematic data analysis was conducted using NVivo software, and coding focussed on people's experiences of MACs, the challenges they faced and their perceptions about models of care for chronic conditions. RESULTS: MACs were considered acceptable to patients and health-care workers because they saved time, prevented unnecessary queues in the clinic and provided people with health education and group support whilst they collected their medication. Some patients and health-care workers felt that MACs reduced stigma for HIV positive patients by treating HIV as any other chronic condition. Staff and patients reported challenges recruiting patients into MACs, including patients not fully understanding the eligibility criteria for the clubs. There were also some practical challenges during the implementation of the clubs, but MACs have shown that it is possible to learn from ART provision and enable stable HIV and NCD patients to collect chronic medication together in a group. CONCLUSIONS: Extending models of care previously only offered to HIV-positive cohorts to NCD patients can help to de-stigmatise HIV, allow for the efficient clinical management of co-morbidities and enable patients to benefit from peer support. Through MACs, we have demonstrated that an integrated approach to providing medication for chronic diseases including HIV can be implemented in resource-poor settings and could thus be rolled out in other similar contexts.