The relationship between leptin-to-adiponectin ratio and HOMA-IR and metabolic syndrome in five African-origin populations.

OBJECTIVE: This cross-sectional study aims to assess the associations between serum leptin, adiponectin, leptin-to-adiponectin ratio (L/A ratio), and metabolic syndrome (MS) and HOMA-IR in five African-origin populations: Ghana, South Africa, Jamaica, Seychelles, and US. METHODS: Clinical measures included serum glucose, insulin, adipokines, blood pressure and anthropometric measures. MS was determined using the Harmonized criteria. The final sample included 2087 adults. RESULTS: After adjusting for age, sex, and fat mass, L/A ratio, unlike HOMA-IR, was significantly associated with MS across all sites (p < 0.001). Within sites, L/A ratio was only associated with MS and HOMA-IR in the US (p < 0.001) and South Africa (p < 0.01), respectively. Leptin was associated with MS in South Africa only (p < 0.05) but was significantly associated with HOMA-IR across all five sites and within the US (p < 0.05). Similarly, adiponectin was associated with HOMA-IR in South Africa (p < 0.05) and with MS across all five sites (p < 0.001) and within each site separately, except Ghana. CONCLUSIONS: Our study suggests that individuals of the African diaspora in different geographical locations may differ in the determinants of MS. Future studies should investigate the determinants for the disparate relationships between MS, IS and adipokines across different African-origin populations.

Greater male variability in daily energy expenditure develops through puberty.

There is considerably greater variation in metabolic rates between men than between women, in terms of basal, activity and total (daily) energy expenditure (EE). One possible explanation is that EE is associated with male sexual characteristics (which are known to vary more than other traits) such as musculature and athletic capacity. Such traits might be predicted to be most prominent during periods of adolescence and young adulthood, when sexual behaviour develops and peaks. We tested this hypothesis on a large dataset by comparing the amount of male variation and female variation in total EE, activity EE and basal EE, at different life stages, along with several morphological traits: height, fat free mass and fat mass. Total EE, and to some degree also activity EE, exhibit considerable greater male variation (GMV) in young adults, and then a decreasing GMV in progressively older individuals. Arguably, basal EE, and also morphometrics, do not exhibit this pattern. These findings suggest that single male sexual characteristics may not exhibit peak GMV in young adulthood, however total and perhaps also activity EE, associated with many morphological and physiological traits combined, do exhibit GMV most prominently during the reproductive life stages.

Variability in energy expenditure is much greater in males than females.

In mammals, trait variation is often reported to be greater among males than females. However, to date, mainly only morphological traits have been studied. Energy expenditure represents the metabolic costs of multiple physical, physiological, and behavioral traits. Energy expenditure could exhibit particularly high greater male variation through a cumulative effect if those traits mostly exhibit greater male variation, or a lack of greater male variation if many of them do not. Sex differences in energy expenditure variation have been little explored. We analyzed a large database on energy expenditure in adult humans (1494 males and 3108 females) to investigate whether humans have evolved sex differences in the degree of interindividual variation in energy expenditure. We found that, even when statistically comparing males and females of the same age, height, and body composition, there is much more variation in total, activity, and basal energy expenditure among males. However, with aging, variation in total energy expenditure decreases, and because this happens more rapidly in males, the magnitude of greater male variation, though still large, is attenuated in older age groups. Considerably greater male variation in both total and activity energy expenditure could be explained by greater male variation in levels of daily activity. The considerably greater male variation in basal energy expenditure is remarkable and may be explained, at least in part, by greater male variation in the size of energy-demanding organs. If energy expenditure is a trait that is of indirect interest to females when choosing a sexual partner, this would suggest that energy expenditure is under sexual selection. However, we present a novel energetics model demonstrating that it is also possible that females have been under stabilizing selection pressure for an intermediate basal energy expenditure to maximize energy available for reproduction.

Metabolic acceleration and the evolution of human brain size and life history.

Humans are distinguished from the other living apes in having larger brains and an unusual life history that combines high reproductive output with slow childhood growth and exceptional longevity. This suite of derived traits suggests major changes in energy expenditure and allocation in the human lineage, but direct measures of human and ape metabolism are needed to compare evolved energy strategies among hominoids. Here we used doubly labelled water measurements of total energy expenditure (TEE; kcal day(-1)) in humans, chimpanzees, bonobos, gorillas and orangutans to test the hypothesis that the human lineage has experienced an acceleration in metabolic rate, providing energy for larger brains and faster reproduction without sacrificing maintenance and longevity. In multivariate regressions including body size and physical activity, human TEE exceeded that of chimpanzees and bonobos, gorillas and orangutans by approximately 400, 635 and 820 kcal day(-1), respectively, readily accommodating the cost of humans' greater brain size and reproductive output. Much of the increase in TEE is attributable to humans' greater basal metabolic rate (kcal day(-1)), indicating increased organ metabolic activity. Humans also had the greatest body fat percentage. An increased metabolic rate, along with changes in energy allocation, was crucial in the evolution of human brain size and life history.

The associations between alcohol intake and cardiometabolic risk in African-origin adults spanning the epidemiologic transition.

BACKGROUND: Cardiometabolic (CM) risk affects approximately 25% of adults globally, and is diagnosed by meeting 3 out of 5 of the following CM risk factors: elevated blood pressure, high triglycerides, elevated blood sugar, low high-density lipoprotein (HDL) level, and abdominal obesity. Adults with CM risk are approximately 22% more likely to have higher mortality rates, and alcohol consumption may be associated with higher CM risk. While previous studies have investigated this potential connection, the majority of them did not include African-origin adults. Therefore, the study aimed to explore the association between alcohol intake and CM risk in 5 African-origin cohorts, spanning the epidemiologic transition in Ghana, South Africa, Jamaica, Seychelles and the United States of America. METHODS: Measurements included clinical measures for CM risk and self-reported alcohol consumption. Each participant was categorized into one of three drinking categories: non-drinker, light drinker (1-3 drinks daily for men and 1-2 drinks daily for women) and heavy drinker (4 or more drinks every day for men and 3 or more drinks per day for women). Using non-drinker status as the reference, the association between alcohol consumption status and prevalence of each of the five CM risk factors and overall elevated CM risk (having 3 out of 5 risk factors) was explored, adjusting for site, age and sex. Associations were explored using logistic regression and significance was determined using odds ratios (OR) and 95% confidence intervals. RESULTS: Neither light nor heavy drinking was associated with increased odds for having higher CM risk compared to nondrinkers (OR = 1.05, p = 0.792 and OR = 1.11, p = 0.489, respectively). However, light drinking was associated with lower odds for having low high density lipoproteins (HDL) cholesterol (OR = 0.69, p = 0.002) and increased risk for high triglycerides (OR = 1.48, p = 0.030). Heavy drinking was associated with elevated blood pressure (OR = 1.59, p = 0.002), high triglycerides (OR = 1.73, p = 0.006) and decreased risk of low HDL-cholesterol (OR = 0.621, p < 0.0005). Finally, country-specific analyses indicated that the relationship between heavy drinking and elevated CM risk varied widely across sites. CONCLUSION: While several CM risk factors were associated with alcohol consumption, the associations were inconsistent and varied widely across five international cohorts of African-origin. Future studies should focus on understanding the individual site-related effects.

Correction: Single-trait and multi-trait genome-wide association analyses identify novel loci for blood pressure in African-ancestry populations.

[This corrects the article DOI: 10.1371/journal.pgen.1006728.].

Single-trait and multi-trait genome-wide association analyses identify novel loci for blood pressure in African-ancestry populations.

Hypertension is a leading cause of global disease, mortality, and disability. While individuals of African descent suffer a disproportionate burden of hypertension and its complications, they have been underrepresented in genetic studies. To identify novel susceptibility loci for blood pressure and hypertension in people of African ancestry, we performed both single and multiple-trait genome-wide association analyses. We analyzed 21 genome-wide association studies comprised of 31,968 individuals of African ancestry, and validated our results with additional 54,395 individuals from multi-ethnic studies. These analyses identified nine loci with eleven independent variants which reached genome-wide significance (P < 1.25×10-8) for either systolic and diastolic blood pressure, hypertension, or for combined traits. Single-trait analyses identified two loci (TARID/TCF21 and LLPH/TMBIM4) and multiple-trait analyses identified one novel locus (FRMD3) for blood pressure. At these three loci, as well as at GRP20/CDH17, associated variants had alleles common only in African-ancestry populations. Functional annotation showed enrichment for genes expressed in immune and kidney cells, as well as in heart and vascular cells/tissues. Experiments driven by these findings and using angiotensin-II induced hypertension in mice showed altered kidney mRNA expression of six genes, suggesting their potential role in hypertension. Our study provides new evidence for genes related to hypertension susceptibility, and the need to study African-ancestry populations in order to identify biologic factors contributing to hypertension.

Origins of lifetime health around the time of conception: causes and consequences.

Parental environmental factors, including diet, body composition, metabolism, and stress, affect the health and chronic disease risk of people throughout their lives, as captured in the Developmental Origins of Health and Disease concept. Research across the epidemiological, clinical, and basic science fields has identified the period around conception as being crucial for the processes mediating parental influences on the health of the next generation. During this time, from the maturation of gametes through to early embryonic development, parental lifestyle can adversely influence long-term risks of offspring cardiovascular, metabolic, immune, and neurological morbidities, often termed developmental programming. We review periconceptional induction of disease risk from four broad exposures: maternal overnutrition and obesity; maternal undernutrition; related paternal factors; and the use of assisted reproductive treatment. Studies in both humans and animal models have demonstrated the underlying biological mechanisms, including epigenetic, cellular, physiological, and metabolic processes. We also present a meta-analysis of mouse paternal and maternal protein undernutrition that suggests distinct parental periconceptional contributions to postnatal outcomes. We propose that the evidence for periconceptional effects on lifetime health is now so compelling that it calls for new guidance on parental preparation for pregnancy, beginning before conception, to protect the health of offspring.

Independent association of resting energy expenditure with blood pressure: confirmation in populations of the African diaspora.

BACKGROUND: Obesity is a major risk factor for hypertension, however, the physiologic mechanisms linking increased adiposity to elevations in blood pressure are not well described. An increase in resting energy expenditure (REE) is an obligatory consequence of obesity. Previous survey research has demonstrated that REE is an independent predictor of blood pressure, and eliminates the co-linear association of body mass index. This observation has received little attention and there have been no attempts to provide a causal explanation. METHODS: At baseline in an international comparative study on obesity, 289 participants aged 25-44 were recruited from communities in the US, the Seychelles, Ghana and South Africa and had REE measured with indirect calorimetry. All participants were thought to be free of major illness. RESULTS: In multivariate regression models, both systolic and diastolic blood pressure were positively associated with REE (p < 0.01), while body mass index and fat mass were negatively correlated with systolic blood pressure (p < 0.01, and p < 0.05 respectively), but not diastolic blood pressure. CONCLUSIONS: These data confirm previous reports and suggest that a common physiologic abnormality links REE and blood pressure. Elevated catecholamines, a putative metabolic characteristic of obesity, is a possible candidate to explain this association. The direct role of excess adipose tissue is open to question.

Gut microbiota, short chain fatty acids, and obesity across the epidemiologic transition: the METS-Microbiome study protocol.

BACKGROUND: While some of the variance observed in adiposity and weight change within populations can be accounted for by traditional risk factors, a new factor, the gut microbiota, has recently been associated with obesity. However, the causal mechanisms through which the gut microbiota and its metabolites, short chain fatty acids (SCFAs) influence obesity are unknown, as are the individual obesogenic effects of the individual SCFAs (butyrate, acetate and propionate). This study, METS-Microbiome, proposes to examine the influence of novel risk factors, the gut microbiota and SCFAs, on obesity, adiposity and weight change in an international established cohort spanning the epidemiologic transition. METHODS: The parent study; Modeling the Epidemiologic Transition Study (METS) is a well-established and ongoing prospective cohort study designed to assess the association between body composition, physical activity, and relative weight, weight gain and cardiometabolic disease risk in five diverse population-based samples in 2500 people of African descent. The cohort has been prospectively followed since 2009. Annual measures of obesity risk factors, including body composition, objectively measured physical activity and dietary intake, components which vary across the spectrum of social and economic development. In our new study; METS-Microbiome, in addition to continuing yearly measures of obesity risk, we will also measure gut microbiota and stool SCFAs in all contactable participants, and follow participants for a further 3 years, thus providing one of the largest gut microbiota population-based studies to date. DISCUSSION: This new study capitalizes upon an existing, extensively well described cohort of adults of African-origin, with significant variability as a result of the widespread geographic distributions, and therefore variation in the environmental covariate exposures. The METS-Microbiome study will substantially advance the understanding of the role gut microbiota and SCFAs play in the development of obesity and provide novel obesity therapeutic targets targeting SCFAs producing features of the gut microbiota. TRIAL REGISTRATION: Registered NCT03378765 Date first posted: December 20, 2017.

Dietary factors and fibroblast growth factor-23 levels in young adults with African ancestry.

Fibroblast growth factor-23 (FGF23), a phosphaturic hormone secreted mainly by osteocytes, maintains serum phosphate levels within a tight range by promoting phosphaturia. Previous studies have mainly focused on the link between FGF23 levels and dietary intake of phosphate, but other dietary factors may also influence FGF23 levels. This cross-sectional study pooled three populations of young adults with African ancestry (452 in Chicago, IL, USA; 477 in Victoria, Seychelles; and 482 in Kumasi, Ghana) with estimated glomerular filtration rate >80 ml/min/1.73 m2 to examine the association of dietary factors based on two 24-h recalls with FGF23 levels measured using a C-terminal assay. Linear regression was used to examine the association between log-transformed FGF23 levels and quartiles of calorie-adjusted dietary factors with adjustment for covariates. In the pooled sample of 1411 study participants, the mean age was 35.2 (6.2) years and 45.3% were male. Median plasma C-terminal FGF23 values in relative units (RU)/ml were 59.5 [interquartile range (IQR) 44.1, 85.3] in the USA, 43.2 (IQR 33.1, 57.9) in Seychelles, and 34.0 (IQR 25.2, 50.4) in Ghana. With adjustment for covariates, increasing quartiles of calcium and animal protein and decreasing quartiles of vegetable protein, fiber, and magnesium intake were associated with significantly higher FGF23 levels compared to the lowest quartile. After further adjustment for dietary factors, significant trends in FGF23 levels were noted only for quartiles of calcium, fiber, and magnesium intake (P < 0.001). Dietary factors other than phosphate are associated with FGF23 levels in young adults.

Cardiovascular risk status of Afro-origin populations across the spectrum of economic development: findings from the Modeling the Epidemiologic Transition Study.

BACKGROUND: Cardiovascular risk factors are increasing in most developing countries. To date, however, very little standardized data has been collected on the primary risk factors across the spectrum of economic development. Data are particularly sparse from Africa. METHODS: In the Modeling the Epidemiologic Transition Study (METS) we examined population-based samples of men and women, ages 25-45 of African ancestry in metropolitan Chicago, Kingston, Jamaica, rural Ghana, Cape Town, South Africa, and the Seychelles. Key measures of cardiovascular disease risk are described. RESULTS: The risk factor profile varied widely in both total summary estimates of cardiovascular risk and in the magnitude of component factors. Hypertension ranged from 7% in women from Ghana to 35% in US men. Total cholesterol was well under 200 mg/dl for all groups, with a mean of 155 mg/dl among men in Ghana, South Africa and Jamaica. Among women total cholesterol values varied relatively little by country, following between 160 and 178 mg/dl for all 5 groups. Levels of HDL-C were virtually identical in men and women from all study sites. Obesity ranged from 64% among women in the US to 2% among Ghanaian men, with a roughly corresponding trend in diabetes. Based on the Framingham risk score a clear trend toward higher total risk in association with socioeconomic development was observed among men, while among women there was considerable overlap, with the US participants having only a modestly higher risk score. CONCLUSIONS: These data provide a comprehensive estimate of cardiovascular risk across a range of countries at differing stages of social and economic development and demonstrate the heterogeneity in the character and degree of emerging cardiovascular risk. Severe hypercholesterolemia, as characteristic in the US and much of Western Europe at the onset of the coronary epidemic, is unlikely to be a feature of the cardiovascular risk profile in these countries in the foreseeable future, suggesting that stroke may remain the dominant cardiovascular event.

ASSOCIATION BETWEEN 25-HYDROXYVITAMIN D AND INTACT PARATHYROID HORMONE LEVELS ACROSS LATITUDE AMONG ADULTS WITH AFRICAN ANCESTRY.

OBJECTIVE: To compare levels of 25-hydroxyvitamin D (25[OH]D) associated with a plateauing of intact parathyroid (iPTH) across latitudes among adults with African ancestry. METHODS: This study included approximately 500 adults of African ancestry ages 25 to 45 years living in 4 sites: Chicago, Illinois (41°N), Jamaica (17°N), Ghana (6°N), and South Africa (34°S). Multivariate linear regression models, a nonlinear logistic growth curve model, and piecewise linear models with a single knot were fitted to estimate the 25[OH]D level associated with a plateauing of iPTH with adjustment for covariates. Goodness of fit was compared using computer intensive permutation tests. RESULTS: Mean age was 34.7 (SD 6.2) years, and 46.5% were male. Within each site, the percentage of participants with an iPTH level ≥65 pg/mL was higher among females versus males and was most frequent among South African females (17.1%) and lowest among Jamaican males (0.6%). Goodness of fit tests supported linear regression as the preferred model for the association between iPTH and 25[OH]D in the 4 sites with no 25[OH]D level associated with iPTH plateauing in any site. The slope of the association between 25[OH]D and iPTH differed by latitude; it was strongest in the U.S. (ß = -0.81; 95% confidence interval [CI] = -1.03, -0.59), and weakest in Jamaica (ß = -0.45; 95% CI -0.71, -0.18) with covariate adjustment, but differences in slopes were small. CONCLUSION: The association between 25[OH]D and iPTH appears linear among adults with African ancestry regardless of latitude within a range of 25[OH]D levels between 10 and 60 ng/mL. ABBREVIATIONS: BMI = body mass index CI = confidence interval eGFR = estimated glomerular filtration rate iPTH = intact parathryoid hormone 25[OH]D = 25-hydroxyvitamin D.

The social patterning of risk factors for noncommunicable diseases in five countries: evidence from the modeling the epidemiologic transition study (METS).

BACKGROUND: Associations between socioeconomic status (SES) and risk factors for noncommunicable diseases (NCD-RFs) may differ in populations at different stages of the epidemiological transition. We assessed the social patterning of NCD-RFs in a study including populations with different levels of socioeconomic development. METHODS: Data on SES, smoking, physical activity, body mass index, blood pressure, cholesterol and glucose were available from the Modeling the Epidemiologic Transition Study (METS), with about 500 participants aged 25-45 in each of five sites (Ghana, South Africa, Jamaica, Seychelles, United States). RESULTS: The prevalence of NCD-RFs differed between these populations from five countries (e.g., lower prevalence of smoking, obesity and hypertension in rural Ghana) and by sex (e.g., higher prevalence of smoking and physical activity in men and of obesity in women in most populations). Smoking and physical activity were associated with low SES in most populations. The associations of SES with obesity, hypertension, cholesterol and elevated blood glucose differed by population, sex, and SES indicator. For example, the prevalence of elevated blood glucose tended to be associated with low education, but not with wealth, in Seychelles and USA. The association of SES with obesity and cholesterol was direct in some populations but inverse in others. CONCLUSIONS: In conclusion, the distribution of NCD-RFs was socially patterned in these populations at different stages of the epidemiological transition, but associations between SES and NCD-RFs differed substantially according to risk factor, population, sex, and SES indicator. These findings emphasize the need to assess and integrate the social patterning of NCD-RFs in NCD prevention and control programs in LMICs.

Early-life factors are associated with nocturnal cortisol and glucose effectiveness in Afro-Caribbean young adults.

CONTEXT: Early-life factors (including intrauterine growth retardation) may influence the development of type 2 diabetes. We postulated that birth size is associated with cortisol levels, which itself could alter serum adipomyokines (i.e. adiponectin, IGF-I, myostatin) and glucose metabolism. DESIGN: An observational study with 60 Afro-Caribbean young adults from a birth cohort. MEASUREMENTS: Fasting blood was drawn for serum adiponectin, IGF-I and myostatin. A frequently sampled intravenous glucose tolerance test measured insulin sensitivity (SI), acute insulin response (AIRg), disposition index (DI) and glucose effectiveness (Sg). Body composition was assessed by dual-energy X-ray absorptiometry. Salivary cortisol was collected at home at 0800 and 2300 h. Sex-adjusted correlations were used to explore the relationships between birth size, cortisol and the metabolic variables. RESULTS: The participants were 55% male, mean age 23·1 ± 0·5 years. Birth weight correlated positively with 2300-h cortisol (P = 0·04), although not after adjusting for gestational age. Gestational age was correlated with 2300 h cortisol (r = 0·38, P = 0·03), even after adjusting for birth weight (P = 0·02). 2300 h cortisol was not associated with adiponectin, IGF-I, myostatin, SI, AIRg or DI, but was negatively correlated with Sg (r = -0·30, P = 0·05) even after adjusting for birth and adult anthropometry. Adiponectin, IGF-I and myostatin were unrelated to glucose metabolism. CONCLUSIONS: Gestational age is associated with higher nocturnal cortisol, which in turn is associated with lower glucose effectiveness in adulthood. Higher glucose effectiveness could therefore be a compensatory mechanism to improve glucose uptake.

Richer but fatter: the unintended consequences of microcredit financing on household health and expenditure in Jamaica.

OBJECTIVE: To determine whether there was a difference in wealth and cardiovascular disease (CVD) risk between microcredit loan beneficiaries and community-matched non-beneficiaries (controls). METHODS: Seven hundred and twenty-six households of microcredit loan beneficiaries were matched with 726 controls by age, sex and community. A standardised interviewer administered questionnaire was used to collect data on health and household expenditure. Weights, heights, waist circumference and blood pressure measurements were taken for an adult and one child (6-16 years) from each household. RESULTS: Amongst adults, there was no difference in the prevalence of pre-hypertension and hypertension. More male (68.1% vs. 47.8%) and female beneficiaries (84.5% vs. 77.9%) were overweight/obese. More male (17.2% vs. 7.1%; P < 0.05) and female beneficiaries (68.5% vs. 63.3%; P < 0.05) exhibited substantially increased risk for CVD. Children of beneficiaries displayed higher mean BMI-for-age z-scores than their control peers: males 0.56 [95% CI 0.40-0.72] vs. 0.18 [95% CI 0.02-0.35] (P < 0.001) and females 0.66 [95% CI 0.52-0.80] vs. 0.42 [95% CI 0.29-0.56] (P < 0.001). Based on BMI-for-age z-scores, children of beneficiaries had greater odds of being overweight/obese (OR = 1.46; 95% CI 1.18-1.82) Beneficiaries were economically better off; their mean total annual expenditure and house ownership were significantly higher than controls (P < 0.001). CONCLUSIONS: Microcredit financing is positively associated with wealth acquisition but worsened cardiovascular risk status.

Under-reporting of dietary energy intake in five populations of the African diaspora.

Studies on the role of diet in the development of chronic diseases often rely on self-report surveys of dietary intake. Unfortunately, many validity studies have demonstrated that self-reported dietary intake is subject to systematic under-reporting, although the vast majority of such studies have been conducted in industrialised countries. The aim of the present study was to investigate whether or not systematic reporting error exists among the individuals of African ancestry (n 324) in five countries distributed across the Human Development Index (HDI) scale, a UN statistic devised to rank countries on non-income factors plus economic indicators. Using two 24 h dietary recalls to assess energy intake and the doubly labelled water method to assess total energy expenditure, we calculated the difference between these two values ((self-report - expenditure/expenditure) × 100) to identify under-reporting of habitual energy intake in selected communities in Ghana, South Africa, Seychelles, Jamaica and the USA. Under-reporting of habitual energy intake was observed in all the five countries. The South African cohort exhibited the highest mean under-reporting ( - 52·1% of energy) compared with the cohorts of Ghana ( - 22·5%), Jamaica ( - 17·9%), Seychelles ( - 25·0%) and the USA ( - 18·5%). BMI was the most consistent predictor of under-reporting compared with other predictors. In conclusion, there is substantial under-reporting of dietary energy intake in populations across the whole range of the HDI, and this systematic reporting error increases according to the BMI of an individual.

A comparison of indices of glucose metabolism in five black populations: data from modeling the epidemiologic transition study (METS).

BACKGROUND: Globally, Africans and African Americans experience a disproportionate burden of type 2 diabetes, compared to other race and ethnic groups. The aim of the study was to examine the association of plasma glucose with indices of glucose metabolism in young adults of African origin from 5 different countries. METHODS: We identified participants from the Modeling the Epidemiologic Transition Study, an international study of weight change and cardiovascular disease (CVD) risk in five populations of African origin: USA (US), Jamaica, Ghana, South Africa, and Seychelles. For the current study, we included 667 participants (34.8 ± 6.3 years), with measures of plasma glucose, insulin, leptin, and adiponectin, as well as moderate and vigorous physical activity (MVPA, minutes/day [min/day]), daily sedentary time (min/day), anthropometrics, and body composition. RESULTS: Among the 282 men, body mass index (BMI) ranged from 22.1 to 29.6 kg/m(2) in men and from 25.8 to 34.8 kg/m(2) in 385 women. MVPA ranged from 26.2 to 47.1 min/day in men, and from 14.3 to 27.3 min/day in women and correlated with adiposity (BMI, waist size, and % body fat) only among US males after controlling for age. Plasma glucose ranged from 4.6 ± 0.8 mmol/L in the South African men to 5.8 mmol/L US men, while the overall prevalence for diabetes was very low, except in the US men and women (6.7 and 12 %, respectively). Using multivariate linear regression, glucose was associated with BMI, age, sex, smoking hypertension, daily sedentary time but not daily MVPA. CONCLUSION: Obesity, metabolic risk, and other potential determinants vary significantly between populations at differing stages of the epidemiologic transition, requiring tailored public health policies to address local population characteristics.

Association of car ownership and physical activity across the spectrum of human development: Modeling the Epidemiologic Transition Study (METS).

BACKGROUND: Variations in physical activity (PA) across nations may be driven by socioeconomic position. As national incomes increase, car ownership becomes within reach of more individuals. This report characterizes associations between car ownership and PA in African-origin populations across 5 sites at different levels of economic development and with different transportation infrastructures: US, Seychelles, Jamaica, South Africa, and Ghana. METHODS: Twenty-five hundred adults, ages 25-45, were enrolled in the study. A total of 2,101 subjects had valid accelerometer-based PA measures (reported as average daily duration of moderate to vigorous PA, MVPA) and complete socioeconomic information. Our primary exposure of interest was whether the household owned a car. We adjusted for socioeconomic position using household income and ownership of common goods. RESULTS: Overall, PA levels did not vary largely between sites, with highest levels in South Africa, lowest in the US. Across all sites, greater PA was consistently associated with male gender, fewer years of education, manual occupations, lower income, and owning fewer material goods. We found heterogeneity across sites in car ownership: after adjustment for confounders, car owners in the US had 24.3 fewer minutes of MVPA compared to non-car owners in the US (20.7 vs. 45.1 minutes/day of MVPA); in the non-US sites, car-owners had an average of 9.7 fewer minutes of MVPA than non-car owners (24.9 vs. 34.6 minutes/day of MVPA). CONCLUSIONS: PA levels are similar across all study sites except Jamaica, despite very different levels of socioeconomic development. Not owning a car in the US is associated with especially high levels of MVPA. As car ownership becomes prevalent in the developing world, strategies to promote alternative forms of active transit may become important.