Browsing by Author "Kengne, Andre Pascal"
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- 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 AccessChronic kidney disease in HIV populations: prevalence, risk factors and role of transforming growth factor beta (TGF-߀1) polymorphisms(2019) Ekrikpo, Udeme Ekpenyong; Okpechi, Ikechi; Kengne, Andre Pascal; Bello, Aminu; Dandara, Collet; Wonkam, AmbroiseBackground and purpose: With the advent of antiretroviral therapy, HIV-infected individuals now live longer and are at increased risk of chronic kidney disease (CKD). Also, recent studies indicate a genetic predisposition to CKD in the African HIV population. This work investigated the prevalence of CKD (and its correlates) in the global and local HIV population and proceeded to investigate the diagnostic utility of urinary transforming growth factor-beta-1 (TGF-β1) for CKD in the HIV population and determine the association between polymorphisms of TGF-β1 gene and prevalent CKD. Methods: A meta-analysis was performed to document the prevalence of CKD in the global HIV population. From the local HIV population in Nigeria, the prevalence of CKD and traditional risk factors for cardiovascular disease was determined. Using ELISA, TGF-β1 levels was assayed in the urine samples of HIV patients with or without CKD to investigate the ability of urinary TGF-β1 to diagnose early CKD. SNP genotyping of rs1800469, rs1800470, rs1800471, rs121918282 in TGF-β1, rs60910145 (APOL1), rs73885319 (APOL1), rs71785313 (APOL1) and rs743811 (HMOX1) was performed using predesigned TaqMan genotyping assays. Results: Using meta-analytic methods, the global pooled CKD prevalence was 6.4% (95%CI 5.2–7.7%) with MDRD, and 4.8% (2.9–7.1%) with CKD-EPI. Among the WHO regions, Africa had the highest MDRD-based prevalence, 7.9% (5.2-11.1%) with the West African subregion carrying the heaviest burden, 14.6% (9.9- 20.0%). Among the local HIV population, using the CKD-EPI equation, the prevalence of CKD was 13.4% (11.6- 15.4%). Hypertension prevalence was 26.7% (25.5-28.0%); diabetes 5.6% (4.5-6.7%); obesity 8.3% (7.6-9.1%) and dyslipidaemia 29.1% (26.1-32.1%). HIV-infected individuals with CKD had significantly higher levels of urinary TGF-β1-creatinine ratio (uTGFβ1Cr) after controlling for potential confounding factors in regression models. However, within the CKD-HIV group, uTGFβ1Cr reduced as CKD stage worsened. The presence of APOL1 genetic risk independently increased the risk of CKD (OR 2.54, 95% CI 1.44-4.51) in the HIV population while the TGF-β1 SNP, rs1800470, appeared to have a protective effect (OR 0.44 (95% CI 0.20-0.97). There was no significant association between HMOX1 SNPs and CKD occurrence. Conclusion: There is a high prevalence of CKD (and other cardiovascular risk factors) in the adult HIVpopulation. Urinary TGF-β1 may be useful in the non-invasive detection of early CKD in the HIV population. Genetic testing may be used to predict the risk of CKD in the HIV population.
- ItemOpen AccessThe co-inheritance of alpha-thalassemia and sickle cell anemia is associated with better hematological indices and lower consultations rate in Cameroonian patients and could improve their survival(Public Library of Science, 2014) Rumaney, Maryam Bibi; Bitoungui, Valentina Josiane Ngo; Vorster, Anna Alvera; Ramesar, Raj; Kengne, Andre Pascal; Ngogang, Jeanne; Wonkam, AmbroiseBACKGROUND: Co-inheritance of α-thalassemia was reported to be associated with a delayed age of disease onset among Cameroonian Sickle Cell Anemia (SCA) patients. The present study aimed to explore the correlation between α-thalassemia, hematological indices, and clinical events in these patients. Methods and FINDINGS: We studied 161 Cameroonian SCA patients and 103 controls (59.1% HbAA) with median ages of 17.5 and 23 years. RFLP-PCR was used to confirm SCA genotype and to describe haplotypes in the HBB-like genes cluster. Multiplex Gap-PCR was performed to investigate the 3.7 kb α-globin gene deletions. SNaPshot PCR, capillary electrophoresis and cycle sequencing were used for the genotyping of 10 SNPs in BCL11A , HMIP1/2 , OR51B5/6 and HBG loci, known to influence HbF levels. Generalised linear regression models adjusted for age, sex and SNPs genotypes was used to investigate effects of α-thalassemia on clinical and hematological indices. The median rate of vaso-occlusive painful crisis and hospitalisations was two and one per year, respectively. Stroke was reported in eight cases (7.4%). Benin haplotype was the most prevalent (66.3%; n = 208 chromosomes). Among patients, 37.3% ( n = 60) had at least one 3.7 kb deletion, compared to 10.9% ( n = 6) among HbAA controls (p<0.001). Among patients, the median RBC count increased with the number of 3.7 kb deletions [2.6, 3.0 and 3.4 million/dl, with no, one and two deletions (p = 0.01)]. The median MCV decreased with the number of 3.7 kb deletion [86, 80, and 68fl, with no, one and two deletions (p<0.0001)], as well as median WBC counts [13.2, 10.5 and 9.8×10 9 /L (p<0.0001. The co-inheritance of α-thalassemia was associated with lower consultations rate (p = 0.038). CONCLUSION: The co-inheritance of α-thalassemia and SCA is associated with improved hematological indices, and lower consultations rate in this group of patients. This could possibly improve their survival and explain the higher proportion of α-thalassemia among patients than controls.
- ItemOpen AccessCo-morbid cardiometabolic diseases among people living with HIV/AIDS in Cameroon(2024) Ebasone, Peter Vanes; Kengne, Andre Pascal; Peer, Nasheeta; Dzudie, AnastaseBackground and Purpose: To investigate the effects and mediators of HIV infection and related treatment on the prevalence and incidence of cardiometabolic diseases (CMDs) including hypertension, type 2 diabetes mellitus (T2D), and obesity in people living with HIV (PLWH) in Cameroon. Additionally, three systematic reviews were conducted to assess the global prevalence of hypertension, T2D, and obesity among ART-naïve PLWH; and to evaluate the methodological approaches to mediation analysis and handling missing data in studies on CMDs in PLWH. Methods: The study utilized data from 14,279 PLWH enrolled in the Cameroon arm of the International Epidemiology Databases to Evaluate AIDS (IeDEA). Analyses comprised multinomial and binomial logistic regressions, causal mediation analysis, and Cox proportional hazards regression. Systematic reviews were conducted by searching multiple databases, pooling the prevalence rates of hypertension, T2D, and obesity using a random-effects meta-analysis. Results: In Cameroon, significant determinants of hypertension and T2D included age over 50 years, male sex, and overweight/obesity. ART use was linked to lower odds of T2D, and BMI partially mediated the relationship between ART use and hypertension. Prevalence of overweight/obesity was 37.7% overall, and higher in females. Older age, female sex, and higher CD4 count were associated with increased odds of overweight/obesity, while current smoking was linked to reduced odds. The incidence rate of hypertension was 121.1 per 1,000 person-years, with older age, male sex, and overweight/obesity as predictors. ART exposure reduced the risk of hypertension. The systematic review with meta-analysis revealed a global prevalence of 13.6% for hypertension, 4.0% for T2D, and 12.3% for obesity among ART-naïve PLWH. The review on mediation analysis showed increased adoption of casual mediation frameworks but inconsistencies in reporting. The missing data review revealed both under reporting of missing data and how it was handled. Conclusion: The burden of CMDs in PLWH is significant, driven mainly by established risk factors. emphasizing the need for integrated healthcare strategies that address both HIV/AIDS and CMDs. It also underscores the importance of methodological rigor, which significantly impacts the interpretation and reliability of results.
- 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 AccessPrevalence of dyslipidaemia among adults in Africa: a systematic review and meta-analysis(2019) Nzeale, Jean Jacques Noubiap; Kengne, Andre PascalBackground The burden of dyslipidaemia in Africa remains inadequately characterised. We aimed to estimate the prevalence of dyslipidaemia in African adults from hospital-based and community-based studies. Methods In this systematic review and meta-analysis, we searched MEDLINE via PubMed, EMBASE, African Journals Online, and African Index Medicus for studies published between Jan 1, 1980, and July 31, 2017, without language restriction. We assessed methodological quality of all crosssectional studies reporting on the prevalence of elevated concentrations of total cholesterol, LDL cholesterol, or triglycerides, or low concentrations of HDL cholesterol in adults residing in African countries. We excluded reports on Africans living outside Africa, studies of individuals selected on the basis of existing dyslipidaemia or those including children and adolescents, and case series with a small sample size. The most frequently used cutoffs in the included studies were chosen for the subgroup analysis. We used random-effect model meta-analysis to derive the pooled prevalence of elevated total cholesterol, low HDL cholesterol, elevated LDL cholesterol, and elevated triglyceride concentrations. This study is registered with PROSPERO, number CRD42014015376. Findings 177 studies (294063 participants) were included in the meta-analysis. The pooled prevalence of dyslipidaemia in the general population from population-based studies was 25·5% (95% CI 20·0– 31·4) for elevated concentrations of total cholesterol with a cutoff of at least 5·2 mmol/L, 37·4% (29·4–45·7) for low concentrations of HDL cholesterol with a cutoff of less than 1·0 mmol/L, 28·6% (15·8–43·5) for elevated concentrations of LDL cholesterol with a cutoff of at least 3·3 mmol/L, and 17·0% (11·9–22·7) for elevated concentrations of triglycerides with a cutoff of at least 1·7 mmol/L. Interpretation The prevalence of dyslipidaemia is high in the general adult population in Africa. Ongoing efforts to reduce cardiovascular diseases in Africa should integrate effective detection and treatment of dyslipidaemia.
- ItemOpen AccessSAR1a promoter polymorphisms are not associated with fetal hemoglobin in patients with sickle cell disease from Cameroon(BioMed Central, 2017-05-12) Pule, Gift Dineo; Ngo Bitoungui, Valentina Josiane; Chemegni, Bernard Chetcha; Kengne, Andre Pascal; Wonkam, AmbroiseBackground: Reactivation of adult hemoglobin (HbF) is currently a dominant therapeutic approach to sickle cell disease (SCD). In this study, we have investigated among SCD patients from Cameroon, the association of HbF level and variants in the HU-inducible small guanosine triphosphate-binding protein, secretion-associated and RAS-related (SAR1a) protein, previously shown to be associated with HbF after HU treatment in African American SCD patients. Results: Only patients >5 years old were included; hemoglobin electrophoresis and a full blood count were conducted upon arrival at the hospital. RFLP-PCR was used to describe the HBB gene haplotypes and Gap PCR to investigate the 3.7 kb α-globin gene deletion. The iPLEX Gold Sequenom Mass Genotyping Array and cycle sequencing were used for the genotyping of four selected SNPs in SAR1a (rs2310991; rs4282891; rs76901216 and rs76901220). Genetic analysis was performed using an additive genetic model, under a generalized linear regression framework. 484 patients were studied. No associations were observed between any of the promoter variants and baseline HbF, clinical events or other hematological indices. Conclusion: The results of this study could be explained by possible population-specifcity of some tagging genomic variants associated with HbF production and illustrated the complexity of replicating HbF-promoting variants association results across African populations.