Browsing by Author "Micklesfield, Lisa K"

Now showing 1 - 9 of 9
  • Thumbnail Image
    Item
    Open Access
    Antiretroviral therapy, especially Efavirenz, is associated with low bone mineral density in HIV-infected South Africans
    (Public Library of Science, 2015) Dave, Joel A; Cohen, Karen; Micklesfield, Lisa K; Maartens, Gary; Levitt, Naomi S
    Purpose We determined the prevalence and correlates of low bone mineral density (BMD) in HIV-infected South Africans as there is a paucity of such data from Africa. METHODS: BMD and serum 25-hydroxyvitamin D were measured in HIV-positive participants on antiretroviral therapy (ART) and in those not yet on ART (ART-naïve). RESULTS: We enrolled 444 participants [median age 35(IQR: 30, 40) years; 77% women]. BMD was low (z score <-2SD) in 17% and 5% of participants at the lumbar spine and total hip, respectively. Total hip [0.909 (SD 0.123) vs 0.956 (SD 0.124) g/cm 2 , p = 0.0001] and neck of femur BMD [0.796 (SD 0.130) vs 0.844 (SD 0.120) g/cm 2 , p = 0.0001] were lower in the ART, compared to the ART-naïve group. Vitamin D deficiency was present in 15% of participants and was associated with efavirenz use [adjusted OR 2.04 (95% CI 1.01 to 4.13)]. In a multivariate linear regression, exposure to efavirenz or lopinavir-based ART was associated with lower total hip BMD, whereas higher weight, being male and higher vitamin D concentration were associated with higher total hip BMD (adjusted R 2 = 0.28). Age, weight, sex, and the use of efavirenz-based ART were independently associated with lumbar spine BMD (adjusted R 2 = 0.13). CONCLUSIONS: Vitamin D status, use of efavirenz or lopinavir/ritonavir, weight, age and sex are significantly associated with lower BMD in this young cohort of HIV-infected South Africans.
  • Thumbnail Image
    Item
    Open Access
    Application of Intervention Mapping to develop a community-based health promotion pre-pregnancy intervention for adolescent girls in rural South Africa: Project Ntshembo (Hope)
    (2014-06-20) Draper, Catherine E; Micklesfield, Lisa K; Kahn, Kathleen; Tollman, Stephen M; Pettifor, John M; Dunger, David B; Norris, Shane A
    Abstract Background South Africa (SA) is undergoing multiple transitions with an increasing burden of non-communicable diseases and high levels of overweight and obesity in adolescent girls and women. Adolescence is key to addressing trans-generational risk and a window of opportunity to intervene and positively impact on individuals’ health trajectories into adulthood. Using Intervention Mapping (IM), this paper describes the development of the Ntshembo intervention, which is intended to improve the health and well-being of adolescent girls in order to limit the inter-generational transfer of risk of metabolic disease, in particular diabetes risk. Methods This paper describes the application of the first four steps of IM. Evidence is provided to support the selection of four key behavioural objectives: viz. to eat a healthy, balanced diet, increase physical activity, reduce sedentary behaviour, and promote reproductive health. Appropriate behaviour change techniques are suggested and a theoretical framework outlining components of relevant behaviour change theories is presented. It is proposed that the Ntshembo intervention will be community-based, including specialist adolescent community health workers who will deliver a complex intervention comprising of individual, peer, family and community mobilisation components. Conclusions The Ntshembo intervention is novel, both in SA and globally, as it is: (1) based on strong evidence, extensive formative work and best practice from evaluated interventions; (2) combines theory with evidence to inform intervention components; (3) includes multiple domains of influence (community through to the individual); (4) focuses on an at-risk target group; and (5) embeds within existing and planned health service priorities in SA.
  • Thumbnail Image
    Item
    Open Access
    Has the prevalence of stunting in South African children changed in 40 years? A systematic review
    (BioMed Central, 2015-06-05) Said-Mohamed, Rihlat; Micklesfield, Lisa K; Pettifor, John M; Norris, Shane A
    Background: In the last 20 years, South Africa has experienced political, economic, and demographic transitions accompanied by an epidemiological transition. Like several sub-Saharan countries, the South African population is facing both under–and over–nutrition, and nutrition and lifestyle related chronic disease while the burden of infectious disease remains high. It is critical to understand these trends overtime in order to highlights the pitfalls and successful measures initiatives taken in the efforts to tackle malnutrition. The objective of this systematic review is to investigate the changes in the prevalence of stunting, a chronic form of undernutrition, in South Africa over 40 years, and to derive lessons from the South African experience, a country in an advanced process of transition in sub-Saharan Africa. Methods: We undertook a systematic review of publications selected from PubMed, Science Direct and Scopus. We included studies and surveys published between 1970 and 2013 if they reported the prevalence of stunting (low height-for-age) in children under-6 years of age living in South Africa. We excluded studies conducted in health facility outpatients or hospital wards, or children with known chronic and acute infectious diseases. We extracted Date of data collection, study setting, ethnicity, age, sex, sample size, growth references/standards, diagnostic criteria for stunting and prevalence of stunting from each study. Results: Over the last decade, the national prevalence of stunting has decreased. However, between and within provincial, age and ethnic group disparities remain. Unlike other countries in sub-Saharan Africa, no sex or rural/urban differences were found in preschool children. However, the analysis of long-term trends and identification of vulnerable groups is complicated by the use of different growth references/standards and sampling methods. Conclusion: Despite economic growth, political and social transitions, and national nutritional programs, stunting remains stubbornly persistent and prevalent in South Africa. A multi-sectoral and public health approach is needed to: (i) better monitor stunting over time, (ii) combat malnutrition during the first thousand days of life through continued efforts to improve maternal nutrition during pregnancy and infant feeding practices.
  • Thumbnail Image
    Item
    Open Access
    “Just because you’re pregnant, doesn’t mean you’re sick!” A qualitative study of beliefs regarding physical activity in black South African women
    (BioMed Central, 2016-07-19) Watson, Estelle D; Norris, Shane A; Draper, Catherine E; Jones, Rachel A; van Poppel, Mireille N M; Micklesfield, Lisa K
    Background: Despite the benefits of physical activity during pregnancy, the physiological and psychological changes that occur during this unique period may put women at greater risk of being sedentary. Lifestyle and environmental transitions have left black South African women at increased risk of physical inactivity and associated health risks. Therefore, the aim of this qualitative study was to describe the beliefs regarding physical activity during pregnancy in an urban African population. Methods: Semi-structured interviews (n = 13) were conducted with pregnant black African women during their third trimester. Deductive thematic analysis was completed based on the Theory of Planned Behaviour. Coding and analysis was completed with the assistance of ATLAS.ti software. Results: Participants had a mean age of 28 (19–41) years, and a mean BMI of 30 (19.6–39.0) kg/m2. Although the majority of women believed that physical activity was beneficial, this did not appear to translate into behaviour. Reported reasons for this included barriers such as pregnancy-related discomforts, lack of time, money and physical activity related education, all of which can contribute to a reduced perceived control to become active. Opportunities to participate in group exercise classes was a commonly reported facilitator for becoming active. In addition, influential role players, such as family, friends and healthcare providers, as well as cultural beliefs, reportedly provided the women with vague, conflicting and often discouraging advice about physical activity during pregnancy. Conclusions: This study provides new theoretical insight on the beliefs of urban South African pregnant women regarding physical activity. Findings from this study suggest a holistic approach to improve physical activity compliance during pregnancy, inclusive of physical activity education and exercise opportunities within a community setting. This study presents critical formative work upon which contextually and culturally sensitive interventions can be developed.
  • Thumbnail Image
    Item
    Open Access
    Meeting physical activity guidelines is associated with reduced risk for cardiovascular disease in black South African women; a 5.5-year follow-up study
    (BioMed Central, 2014-05-23) Dickie, Kasha; Micklesfield, Lisa K; Chantler, Sarah; Lambert, Estelle V; Goedecke, Julia H
    Background: Low levels of physical activity (PA) have been associated with increased risk for cardiovascular disease (CVD) and type 2 diabetes (T2D), but few studies have examined whether meeting international PA guidelines is associated with reduced risk in a black South African (SA) population. The aims of this study were to compare body composition and cardio-metabolic risk factors for CVD and T2D between active and inactive groups (part 1, cross-sectional analysis) and, to determine whether PA level predicts changes in body composition and cardio-metabolic risk factors for CVD and T2D at follow-up after 5.5-years (part 2, longitudinal analysis). Methods: Part 1 included a sample of 240 apparently healthy black SA women (26 ± 7 years) who underwent the following measurements at baseline: PA (Global Physical Activity Questionnaire (GPAQ)), body composition and regional fat distribution (dual-energy x-ray absorptiometry and computerised tomography), blood pressure, fasting glucose, insulin and lipid concentrations. For part 2, a sub-sample of women (n = 57) underwent the same measurements after a 5.5-year period. Results: At baseline, 61% of women were classified as meeting the guidelines for moderate- to vigorous-intensity physical activity (MVPA) according to GPAQ. Women who were active had significantly lower body weight (p < 0.001), body fat (BMI, fat mass, % body fat, waist circumference, central and appendicular fat mass, all p < 0.001), and measures of insulin resistance (fasting serum insulin and HOMA-IR, both p = 0.01), and higher high-density lipoprotein cholesterol (p = 0.041), compared to the inactive group. At follow-up, all body fat measures increased significantly in both groups and diastolic blood pressure decreased significantly in those who were active at baseline, but did not change in those who were inactive. Conclusions: Meeting PA guidelines was associated with decreased risk for CVD and T2D in black SA women, but did not prevent the increase in body fat over time. Interventions promoting physical activity to specifically address obesity in this high-risk group are recommended.
  • Thumbnail Image
    Item
    Open Access
    Microvascular endothelial function in a multi-ethnic group of apparently healthy South African men and women: Implications for testing and the relationship between insulin resistance and microvascular reactivity
    (2014) Pienaar, Paula Roxana; Lambert, Estelle V; Micklesfield, Lisa K
    Endothelial dysfunction is associated with cardiovascular disease risk factors and precedes structural changes in the blood vessels that occur prior to clinical manifestations. Measuring ethnic differences in microvascular endothelial function will provide insight into the disparate cardio-metabolic disease profiles that exist within a multi-ethnic South African population. Moreover, it has been shown that insulin resistance is associated with microvascular endothelial dysfunction in obese persons4, but it is unclear whether this relationship is mediated by body fat in apparently healthy individuals with and without insulin resistance. To our knowledge this has not been done in a South African population. Aims: The overall aim of this thesis was to measure microvascular endothelial function using Laser Doppler Imagery (LDI) and iontophoresis of acetylcholine (ACh) and sodium nitroprusside (SNP) in a multi-ethnic, apparently healthy group to determine whether: 1) there are ethnic differences in microvascular endothelial function and 2) whether the association between microvascular endothelial function and insulin resistance (IR) is independent of body fat in women with and without IR.
  • Thumbnail Image
    Item
    Open Access
    Relationships between physical activity, cardiorespiratory fitness and sedentary behaviour, and risk factors for cardiovascular disease and type 2 diabetes, in black South African women
    (2013) Dickie, Kasha Elizabeth; Goedecke, Julia H; Micklesfield, Lisa K
    Non-communicable diseases (NCDs), including cardiovascular disease (CVD) and type 2 diabetes (T2D), constitute the second highest cause of mortality in South Africa (SA) and seem to be exacerbated by the high prevalence of obesity, particularly amongst black SA women. Although the aetiology of obesity is complex, common antecedents for its development include a sedentary lifestyle and poor nutrition. The overall aim of this thesis was to examine the association between physical activity (PA) and risk factors for CVD and T2D in a sample of apparently healthy black SA women. The aims of this thesis were addressed in two separate studies with the following objectives: Study 1: i) to compare body composition and metabolic risk factors for CVD and T2D between active and inactive groups classified according to international PA recommendations for health (Part 1, crosssectional analysis) and ii) to determine whether PA level predicts changes in body composition and metabolic risk factors for CVD and T2D over a 5.5-year follow-up period (Part 2, longitudinal analysis); Study 2: to examine the independent effects of PA, cardiorespiratory fitness (CRF) and sedentary time on body composition and metabolic risk factors for CVD and T2D (cross-sectional analysis). In part 1 of study 1, a sample of 240 apparently healthy black SA women(26±7 years) underwent the following measurements in 2005/6: PA (Global PhysicalActivity Questionnaire (GPAQ)), body composition (dual-energy x-ray absorptiometry and computerised tomography), blood pressure, fasting glucose, insulin and lipid concentrations. Thereafter (part 2), a sub-sample of women (n=57) underwent follow-up testing after a 5.5-year follow period (2010/11), which included additional measurements of objective PA (accelerometry) and CRF (VO2max, ml/kg/min) measured during a submaximal step-test. Study 2 included women from the follow-up subsample and 19 additional women (n=76). Cross-sectional comparisons of objective PA, CRF and sedentary time with body composition and metabolic risk factors for CVD and T2D were examined. Study 1: Using the GPAQ, the majority (61%) of women were sufficiently active, meeting the guidelines for moderate- to vigorous-intensity physical activity (MVPA) according to international criteria. Women who were active had significantly lower body weight (p<0.001), measures of body fat (BMI, fat mass, %body fat, waist circumference, central and appendicular fat mass, p<0.001), and measures of insulin resistance (fasting serum insulin, p=0.010 and HOMA-IR, p=0.010, respectively), and higher high-density lipoprotein cholesterol (HDL-C, p=0.041) compared to the inactive group. At follow-up, bodyweight increased from 82.0±19.6 kg to 89.5±19.2 kg (p<0.001) in the active group, and from 91.0±15.6 kg to 98.3±13.2 kg (p<0.001) in the inactive group, whereas serum lipid concentrations remained unchanged (p>0.05), and diastolic blood pressure decreased significantly in those who were active (78±7 vs. 74±14 mmHg, p=0.039). Study 2: Using accelerometry as an objective measure of PA, more than half (51.3%) of the women met international MVPA criteria and the goal of ≥10 000 steps per day (55.3%). Greater light PA and steps per day, but not MVPA, were associated with lower trunk (central) fat mass (r=-0.25, p=0.03, r=-0.31, p=0.01 and r=-0.09, p=0.42, respectively). Conversely, greater sedentary time was associated with higher TG and TG/HDL-C (r=0.36, p=0.01 and r=0.34, p=0.04, respectively), and these relationships were independent of body fat. In addition, higher CRF was associated with reduced body fat% (r=-0.34, p=0.02) and central fat mass (r=-0.31, p=0.03), as well as reduced insulin resistance (HOMA-IR; r=-0.41, p=0.01). These associations were independent of body fat and PA, but not VAT. CRF was inversely associated with sedentary time (r=-0.31, p=0.03) and not with any of the PA variables (p>0.05). Both PA and CRF level were associated with reduced total and central fat mass, and reduced metabolic risk for CVD and T2D amongst a sample of apparently healthy black SA women. Promotion of increasing daily PA, including light-intensity and MVPA, whilst reducing sedentary time, and increasing CRF should be encouraged to reduce levels of obesity and risk factors for CVD and T2D.
  • Thumbnail Image
    Item
    Open Access
    The association between high-sensitivity C-reactive protein and metabolic risk factors in black and white South African women: a cross-sectional study
    (BioMed Central, 2018-05-07) George, Cindy; Evans, Juliet; Micklesfield, Lisa K; Olsson, Tommy; Goedecke, Julia H
    Background High-sensitivity C-reactive protein (hsCRP) is associated with metabolic risk, however it is unclear whether the relationship is confounded by racial/ethnic differences in socioeconomic status (SES), lifestyle factors or central adiposity. The aims of the study was, (1) to investigate whether hsCRP levels differ by race/ethnicity; (2) to examine the race/ethnic-specific associations between hsCRP, HOMA-IR and serum lipids [total cholesterol (TC), triglycerides (TG), high-density lipoproteins (HDL-C) and low-density lipoproteins (LDL-C)]; and (3) to determine whether race/ethnic-specific associations are explained by SES, lifestyle factors or waist circumference (WC). Methods The convenience sample comprised 195 black and 153 white apparently health women, aged 18–45 years. SES (education, assets and housing density) and lifestyle factors (alcohol use, physical activity and contraceptive use) were collected by questionnaire. Weight, height and WC were measured, and fasting blood samples collected for hsCRP, glucose, insulin, and lipids. Results Black women had higher age- and BMI-adjusted hsCRP levels than white women (p = 0.047). hsCRP was associated with HOMA-IR (p < 0.001), TG (p < 0.001), TC (p < 0.05), HDL-C (p < 0.05), and LDL-C (p < 0.05), independent of age and race/ethnicity. The association between hsCRP and lipids differed by race/ethnicity, such that hsCRP was positively associated with TG and LDL-C in white women, and inversely associated with HDL-C in black women. Higher hsCRP was also associated with higher TC in white women and lower TC in black women. Furthermore, when adjusting for SES and lifestyle factors, the associations between hsCRP, and TC and TG, remained, however the associations between hsCRP, and HDL-C and LDL-C, were no longer significant. Conclusion Although circulating hsCRP may identify individuals at increased metabolic risk, the heterogeneity in these associations between racial/ethnic groups highlights the need for prospective studies investigating the role of hsCRP for risk prediction in different populations.
  • Thumbnail Image
    Item
    Open Access
    Understanding factors associated with sarcopenic obesity in older African women from a low-income setting: a cross-sectional analysis
    (2021-04-14) Mendham, Amy E; Goedecke, Julia H; Micklesfield, Lisa K; Brooks, Naomi E; Faber, Mieke; Christensen, Dirk L; Gallagher, Iain J; Lundin-Olsson, Lillemor; Myburgh, Kathryn H; Odunitan-Wayas, Feyisayo A; Lambert, Estelle V; Kalula, Sebastiana; Hunter, Angus M
    Abstract Background High rates of food insecurity, obesity and obesity-related comorbidities in ageing South African (SA) women may amplify the risk of developing sarcopenic obesity. This study aimed to investigate the prevalence and correlates of sarcopenic obesity and its diagnostic components [grip strength, appendicular skeletal muscle mass (ASM) and body mass index (BMI)] in older SA women from a low-income setting. Methods This cross-sectional study recruited black SA women between the ages of 60–85 years (n = 122) from a low-income community. Testing included a fasting blood sample (markers of cardiometabolic risk, HIV), whole body and regional muscle and fat mass (dual-energy absorptiometry x-ray), anthropometry, blood pressure, functional movement tests, current medication use, demographic and health questionnaires, physical activity (PA; accelerometery), household food insecurity access scale, and a one-week quantified food frequency questionnaire. Foundation for the National Institutes of Health (FNIH) criteria (grip strength and ASM, adjusted for BMI) were used to classify sarcopenia. Participants with sarcopenia alongside a BMI of > 30.0 kg/m2 were classified as having sarcopenic obesity. Prevalence using other criteria (European Working Group on Sarcopenia in Older People, Asian Working Group for Sarcopenia and the International Working Group for Sarcopenia) were also explored. Results The prevalence of sarcopenia was 27.9%, which comprised of sarcopenia without obesity (3.3%) and sarcopenic obesity (24.6%). Other classification criteria showed that sarcopenia ranged from 0.8–14.7%, including 0.8–9.8% without obesity and 0–4.9% with sarcopenic obesity. Using multivariate-discriminant analysis (OPLS-DA) those with sarcopenic obesity presented with a descriptive profile of higher C-reactive protein, waist circumference, food security and sedentary time than women without sarcopenic obesity (p = 0.046). A similar profile described women with low BMI-adjusted grip strength (p < 0.001). Conclusions The majority of women with sarcopenia were also obese (88%). We show a large discrepancy in the diagnostic criteria and the potential for significantly underestimating the prevalence of sarcopenia if BMI is not adjusted for. The main variables common to women with sarcopenic obesity were higher food security, lower PA and chronic inflammation. Our data highlights the importance of addressing obesity within these low-income communities to ensure the prevention of sarcopenic obesity and that quality of life is maintained with ageing.