Body mass index cut-points to identify cardiometabolic risk in black South Africans

Improvements in Maternal Cardiovascular Health Over the Perinatal Period Longitudinally Predict Lower Postpartum Psychological Distress Among Individuals Who Began Their Pregnancies With Overweight or Obesity

BACKGROUND

Adverse cardiovascular events during pregnancy (eg, preeclampsia) occur at higher rates among individuals with overweight or obesity (body mass index ≥25 kg/m2) and have been associated with postpartum depression. The present study examined whether changes in cardiovascular health (CVH) during the perinatal period, as defined by the American Heart Association's Life's Essential 8 framework, predicted postpartum psychological functioning among individuals with prepregnancy body mass index ≥25 kg/m2.

METHODS AND RESULTS

Pregnant individuals (N = 226; mean ± SD age = 28.43 ± 5.4 years; mean body mass index = 34.17 ± 7.15 kg/m2) were recruited at 12 to 20 weeks of gestation (mean, 15.64 ± 2.45 weeks) for a longitudinal study of health and well-being. Participants completed ratings of depression and perceived stress and reported on CVH behaviors (dietary intake, physical activity, nicotine exposure, and sleep) at baseline and at 6 months postpartum. Body mass index and CVH behaviors were used to calculate a composite CVH score at both time points. Linear regression analyses were performed to examine whether change in CVH related to postpartum symptom scores. Because sleep was measured in only a subset of participants (n = 114), analyses were conducted with and without sleep. Improved CVH was associated with lower postpartum depression (β = -0.18, P<0.01) and perceived stress (β = -0.13, P=0.02) scores. However, when including sleep, these relationships were no longer significant (all P>0.4).

CONCLUSIONS

Improvements in CVH from early pregnancy to 6 months postpartum were associated with lower postpartum depressive symptoms and perceived stress but not when including sleep in the CVH metric, potentially due to the large reduction in sample size. These data suggest that intervening during pregnancy to promote CVH may improve postpartum psychological functioning among high-risk individuals.

Anthropometric indices and cut-off points for screening of metabolic syndrome among South African taxi drivers

Background

Detecting the early onset of metabolic syndrome (MetS) allows for quick intervention which may slow progression to a variety of health consequences, hence, determining the best measurement to detect MetS is essential.

Aim

This research aimed at examining the MetS predictive power of anthropometric indices, such as body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR), body shape index (ABSI), body roundness index (BRI), percentage body fat (%BF), conicity index (CI), and Clínica Universidad de Navarra-body adiposity estimator (CUN-BAE) to determine the cut-off points to identify male South African taxi drivers with MetS.

Method

A cross-sectional study was conducted among 185 male taxi drivers. Their weight, height, WC, blood lipid profile were measured. International Diabetes Federation (IDF) definition was used to define MetS. Receiver Operating Characteristic (ROC) curves were used to compare the predictive ability of Anthropometric indices to detect MetS.

Results

The mean age of the participants was 39.84 years. Overall, 41.6% (N = 77) of the participants presented with MetS. The mean values for BMI, WC, WHtR, %BF, BRI, CUN-BAE, ABSI and CI were 28.60 ± 6.20 kg/m², 99.13 ± 17.59 cm, 0.58 ± 0.10, 27.28 ± 8.28%, 5.09 ± 2.33, 27.78 ± 8.34, 0.08 ± 0.01 and 1.70 ± 0.19, respectively. The mean values for these indices were significantly (p < 0.001) higher in participants with MetS. The highest area under the curve (AUC) outcomes for screening MetS were for the %BF and CUN-BAE, followed by the BMI and WHtR, and lastly the BRI. All these anthropometric indices had outstanding discriminatory powers for predicting MetS with AUCs and sensitivity values above 80%. The BMI, WHtR, %BF, BRI, and CUN-BAE, had cut-off points for detection of metS in South African men at 28.25 kg/m², 0.55, 25.29%, 4.55, and 27.10, respectively. Based on the logistic regression models abnormal BMI, WHtR, %BF, BRI, CUN-BAE, TG, FBG, systolic BP, diastolic BP and WC showed increased risk of MetS.

Conclusion

While the %BF, CUN-BAE, BMI, WC, WHtR, BRI, CI and CUN-BAE could predict MetS among South African male taxi drivers, these indices were less effective in predicting the individual MetS risk factors such as TG, BP, and FBG.

The Metabolic Profiles of Metabolically Healthy Obese and Metabolically Unhealthy Obese South African Adults over 10 Years

Obesity is associated with an increased cardiometabolic risk, but some individuals maintain metabolically healthy obesity (MHO). The aims were to follow a cohort of black South African adults over a period of 10 years to determine the proportion of the group that maintained MHO over 10 years, and to compare the metabolic profiles of the metabolically healthy and metabolically unhealthy groups after the follow-up period. The participants were South African men (n = 275) and women (n = 642) from the North West province. The prevalence of obesity and the metabolic syndrome increased significantly. About half of the metabolically healthy obese (MHO) adults maintained MHO over 10 years, while 46% of the women and 43% of men became metabolically unhealthy overweight/obese (MUO) at the end of the study. The metabolic profiles of these MHO adults were similar to those of the metabolically healthy normal weight (MHNW) group in terms of most metabolic syndrome criteria, but they were more insulin resistant; their CRP, fibrinogen, and PAI-1act were higher and HDL-cholesterol was lower than the MHNW group. Although the metabolic profiles of the MUO group were less favourable than those of their counterparts, MHO is a transient state and is associated with increased cardiometabolic risk.

Lifestyle factors associated with the transition from healthy to unhealthy adiposity among black South African adults over 10 years

BACKGROUND AND AIMS

Obesity is associated with an increasing prevalence of cardiovascular diseases in Africa, but some obese individuals maintain cardiometabolic health. The aims were to track metabolically healthy overweight or obesity (MHO) over 10 years in African adults and to identify factors associated with a transition to metabolically unhealthy overweight or obesity (MUO).

METHODS AND RESULTS

The participants were the South African cohort of the international Prospective Urban and Rural Epidemiological study. From the baseline data of 1937 adults, 649 women and 274 men were followed for 10 years. The combined overweight and obesity prevalence of men (19.2%-23.8%, p = .02) and women (58%-64.7%, p < .001), and the prevalence of the metabolic syndrome in all participants (25.4%-40.2%, p < .001) increased significantly. More than a quarter (26.2%) of the women and 10.9% of men were MHO at baseline, 11.4% of women and 5.1% of men maintained MHO over 10 years, while similar proportions (12.3% of women, 4.7% of men) transitioned to MUO. Female sex, age, and total fat intake were positively associated with a transition to MUO over 10 years, while physical activity was negatively associated with the transition. HIV positive participants were more likely to be MHO at follow-up than their HIV negative counterparts.

CONCLUSIONS

One in two black adults with BMI ≥25 kg/m² maintained MHO over 10 years, while a similar proportion transitioned into MUO. Interventions should focus on lower fat intakes and higher physical activity to prevent the transition to MUO.

Sarcopenic Obesity in Africa: A Call for Diagnostic Methods and Appropriate Interventions

This perspective aims to highlight the lack of current knowledge on sarcopenic obesity in Africa and to call for diagnostic methods and appropriate interventions. Sarcopenic obesity has been defined as obesity that occurs in combination with low muscle mass and function, which is typically evident in older adults. However, there has been no clear consensus on population-specific diagnostic criterion, which includes both gold-standard measures that can be used in a more advanced health care system, and surrogate measures that can be used in low-income settings with limited resources and funding. Importantly, low and middle-income countries (LMICs) across Africa are in an ongoing state of economic and social transition, which has contributed to an increase in the aging population, alongside the added burden of poverty, obesity, and associated co-morbidities. It is anticipated that alongside the increased prevalence of obesity, these countries will further experience an increase in age-related musculoskeletal diseases such as sarcopenia. The developmental origins of health and disease (DOHaD) approach will allow clinicians and researchers to consider developmental trajectories, and the influence of the environment, for targeting high-risk individuals and communities for treatment and/or prevention-based interventions that are implemented throughout all stages of the life course. Once a valid and reliable diagnostic criterion is developed, we can firstly assess the prevalence and burden of sarcopenic obesity in LMICs in Africa, and secondly, develop appropriate and sustainable interventions that target improved dietary and physical activity behaviors throughout the life course.

Estimation of sex based on postcranial elements in European American and Latin American populations

This study assesses the use of postcranial elements for sex estimation taking population variability into account. European American and Latin American populations are independently analyzed. Nine measurements from postcranial elements were collected from 72 European American individuals, and 59 Latin American individuals. Statistical analyses were performed using the Statistical Package for Social Science (SPSS) version 15. Statistical analyses were conducted to corroborate that there were no intra- or interobserver errors. In both populations, significant differences were found on all measured traits between males and females, except Scapular Breadth in Latin Americans. According to Discriminant Function Analysis (DFA) in the European American population the Ulna Minimum Breadth of the Olecranon (UMBO) correctly classified 91.3% of individuals. When this parameter was combined with the Diameter of Humeral Head (HHD), the two correctly classified 98% of individuals. In Latin Americans, the UMBO correctly classified 82.4% of the individuals. When combined with HHD, the measurements correctly classified 79.4% individuals. UMBO is the most useful trait to correctly assign the sex of the remains in both populations. Including the HHD improved accuracy rates in the European American sample. These results are in agreement with previous studies, which named the humerus as one of the potentially useful bones to consider for sex estimation based on its accuracy. Thus, these two anatomical regions could be used alone or in combination with other methodologies for sex estimation, which is particularly important in situations of fragmentary remains and incomplete skeletons.

Development and validation of the body shape scale (BOSHAS) for assessing body shape perception in African populations

Background

As a consequence of ‘Western’ acculturation, eating disorders and body image disturbances, such as fatness phobia and body dysmorphic disorders towards musculature and body shape, are emerging in Africa, with young people the most affected. It is therefore important to accurately assess perceptions of body shape. However, the existing body image assessment scales lack sufficient accuracy and validity testing to compare body shape perception across different African populations. The purpose of this study was to develop and validate the Body Shape Scale (BOSHAS) to evaluate body shape perceptions related body image disorders in African populations.

Methods

To develop the BOSHAS, anthropometric measures of 80 Cameroonians and 81 Senegalese (both sexes included; 40.1% females overall) were taken for three body shape criteria: somatotype components, body mass index (BMI) and waist-to-hip ratio. Subjects were selected to cover a wide variability in body shape and were photographed in full face and profile positions. To validate the BOSHAS, the scale was administered twice (2 weeks apart) to 106 participants (aged 31.2 ± 12.6 years) to assess its reliability. In addition, a questionnaire measuring different aspects of body shape (e.g. musculature) was also administered (n = 597; aged 36.7 ± 15.6 years) to assess its convergent validity.

Results

The BOSHAS includes two sex-specific subscales of 10 photographs each. Most participants were able to repeat their BOSHAS preference order. Test-retest reliability was also consistent in estimating Current Body Shape (CBS), Desired Body Shape and Ideal Body Shape for participants and their partners. CBS was correlated with BMI, and different BOSHAS indices were consistent with declarations obtained by questionnaire.

Conclusions

The BOSHAS is the first sex-specific scale of real African models photographed in face and profile, including large body shape variability. The validation protocol showed good validity and reliability for evaluating body shape perceptions and dissatisfaction of Africans.

Predicting metabolic syndrome by anthropometric measures among adults 35-65 years in the west of Iran; a cross sectional study from an Iranian RaNCD cohort data

AIMS

Anthropometric indices have been proposed for the early detection of metabolic syndrome (MetS) and its risk factors. The present study aimed to determine optimal cutoff points for the Body Mass Index (BMI), Waist Circumference (WC), and Waist Hip Ratio (WHR) in the prediction of MetS.

METHODS

This cross-sectional study was performed on 9746 adults 35-65 years, recruited in Ravansar Non-Communicable Diseases (RaNCD) cohort. The receiver operating characteristic (ROC) curve analysis was used to compare the predictive validity and determine optimal cutoff values.

RESULTS

The optimal cutoff points for BMI, WC and WHR were 27.3 kg/m² (AUC: 78.6; 95%CI 77.1, 80.1), 97 cm (AUC: 63.8; 95%CI 60.4, 67.2) and 0.95 (AUC: 75.5; 95% CI 73.9, 77.1), respectively in men for the prediction of MetS. But in women the optimal cutoff points for BMI, WC and WHR were 28.6 kg/m² (AUC: 65.7; 95%CI 62.1, 69.4), 98.1 cm (AUC: 65.6; 95%CI 62.4,68.8) and 0.95 (AUC:62.39; 95%CI 60.9,63.9). The risk of MetS in men and women with a BMI higher than the optimal cutoff point was respectively 2.23 and 2.30 times higher than that in those with a WC lower than the cutoff point.

CONCLUSIONS

BMI is a better predictor of MetS than WC and WHR in adults 35-65 years. We recommend that the optimal cut off point be set for men 27.3 kg/m² and for women 28.6 kg/m².

Leveraging the urban-rural divide for epigenetic research

Urbanization coincides with a complex change in environmental exposure and a rapid increase in noncommunicable diseases (NCDs). Epigenetics, including DNA methylation (DNAm), is thought to mediate part of the association between genetic/environmental exposure and NCDs. The urban-rural divide provides a unique opportunity to investigate the effect of the combined presence of multiple forms of environmental exposure on DNAm and the related increase in disease risk. This review evaluates the ability of three epidemiological study designs (migration, income-comparative and urban-rural designs) to investigate the role of DNAm in the association between urbanization and the rise in NCD prevalence. We also discuss the ability of each study design to address the gaps in the current literature, including the complex methylation-mediated risk attributable to the cluster of forms of exposure characterizing urban and rural living, while providing a platform for developing countries to leverage their demographic discrepancies in future research ventures.

Comparison of dietary and plasma phospholipid fatty acids between normal weight and overweight black South Africans according to metabolic health: The PURE study

BACKGROUND

Information regarding circulating fatty acids (FA) in association with metabolic health in black Africans is scarce, while the usefulness of circulating FAs as biomarkers of dietary fat intake and predictors for medical conditions is increasing.

OBJECTIVE

We compared eleven dietary and the levels of 26 plasma phospholipid FAs in metabolically healthy and unhealthy phenotypes in black South African adults.

METHODS

Adults from the South African arm of the Prospective Urban and Rural Epidemiology study baseline (n = 711) were categorised into four groups, namely normal weight without metabolic syndrome (MetS) (MHNW), normal weight with MetS (MUNW), metabolically healthy overweight/obese (MHO) and metabolically unhealthy overweight/obese (MUO). Dietary and plasma phospholipid FAs were measured by a quantitative food frequency questionnaire and gas chromatography-tandem mass spectrometry, respectively. We compared dietary FAs, plasma phospholipid FAs, and estimated desaturase activity between the metabolic status groups using ANCOVA adjusted for age and energy intake.

RESULTS

MetS was diagnosed in 35% of the participants. After adjustment for age and total energy intake, in comparison to the MHNW reference group, saturated dietary FAs (C14:0 to C18:0) and alpha-linolenic acid intakes were higher in both overweight/obese groups (MHO and MUO), while linoleic acid intakes were higher in the MUO group only. Plasma levels of most saturated FAs (C18:0 to C22:0) and PUFAs were higher, whereas selected MUFAs, palmitic acid, and estimated desaturase activities were lower in the overweight/obese groups.

CONCLUSIONS

The overweight groups generally had higher fat intakes than normal-weight groups, but lower plasma levels of palmitic, palmitoleic, oleic, cis-vaccenic and estimated desaturase activities. Therefore, in this population, lower plasma levels of palmitic, palmitoleic, oleic, and cis-vaccenic acids and decreased estimated desaturase activities may be biomarkers of abnormal metabolic health in overweight/obese study participants.

The association between anthropometric measures and physical performance in black adults of the North West Province, South Africa

OBJECTIVE

This study investigated associations between anthropometric measures and physical performance in black South African adults. It was hypothesized that noninvasive, simple anthropometric measurements, such as calf circumference (CC) and body mass index (BMI), may be useful predictors of physical performance and strength.

METHODS

Black human immunodeficiency virus (HIV) negative men and women (aged 32-93 years) participating in the Prospective Urban and Rural Epidemiology (PURE) study were enrolled at baseline in 2005 = 1428). Men and women's anthropometry, socio-demographics and physical activity (PA) were assessed at baseline, 5- and 10-year follow-up. Physical performance (walk speed, chair stand and handgrip strength [HGS]) were assessed at 10-year follow-up. Linear regression models adjusted for potential confounders were used to evaluate the association between anthropometric measures and physical performance.

RESULTS

The combined overweight and obesity prevalence among both men (P = .02) and women (P < .001) increased significantly over 10 years, with significant increases over time in BMI and CC in the women, whereas PA decreased significantly over time in both men and women (P < .0001). BMI and CC were positively associated with HGS in the men (P = .02, P < .0001) and women (P < .0001), while CC was positively associated with walk speed in men only (P = .006) in the cross-sectional analysis of 2015 measurements.

CONCLUSION

BMI and CC in both men and women were positively associated with HGS, but CC was associated with walk speed in the men only. Our study suggests that CC may be a useful predictor of physical performance in black men and to a limited extent in black women.

Predictors of Hypertension in a Population of Undergraduate Students in Sierra Leone

We report on the first survey of hypertension in undergraduates in Sierra Leone. Levels of hypertension (12%) and obesity (4%) appear low compared to the general population but given the rapid increase of both and the expectation that many graduates will enter the formal employment sector and a sedentary lifestyle, there is still cause for concern. We measured their BMI (body mass index) and used a questionnaire to investigate demographic and lifestyle choices. In agreement with most authorities, we found that BMI and age were statistically significant predictors of systolic and diastolic blood pressure but that the explanatory power was low (r = 0.21 to 0.27). Men may be more sensitive than women to an increase in BMI on blood pressure (p < 0.1). We failed to find statistically significant relationships with ethnicity, religion, stress, course of study, levels of physical activity, diet, smoking, or consumption of caffeine and alcohol. Family history of hypertension, consumption of red palm oil, and self-diagnosed attacks of typhoid fever were close to conventional levels of significance (p < 0.1). We intend to use this as a baseline for longitudinal studies to assess risks and suggest appropriate public health action.

Interethnic Differences in Serum Lipids and Implications for Cardiometabolic Disease Risk in African Ancestry Populations

African Americans generally have a healthier lipid profile (lower triglycerides and higher high-density lipoprotein cholesterol concentration) compared with those of other ethnicities. Paradoxically, African Americans do not experience a decreased risk of the cardiometabolic diseases that serum lipids are expected to predict. This review explores this mismatch between biomarker and disease among African ancestry individuals by investigating the presence of interethnic differences in the biological relationships underlying the serum lipids-disease association. This review also discusses the physiologic and genomic factors underlying these interethnic differences. Additionally, because of the importance of serum lipids in assessing disease risk, interethnic differences in serum lipids have implications for identifying African ancestry individuals at risk of cardiometabolic disease. Where possible, data from Africa is included, to further elucidate these ancestral differences in the context of a different environmental background.