RESUMO
Sleep disorders are increasingly being characterized in modern society as contributing to a host of serious medical problems, including obesity and metabolic syndrome. Changes to the microbial community in the human gut have been reportedly associated with many of these cardiometabolic outcomes. In this study, we investigated the impact of sleep length on the gut microbiota in a large cohort of 655 participants of African descent, aged 25-45, from Ghana, South Africa (SA), Jamaica, and the United States (US). The sleep duration was self-reported via a questionnaire. Participants were classified into 3 sleep groups: short (<7hrs), normal (7-<9hrs), and long (≥9hrs). Forty-seven percent of US participants were classified as short sleepers and 88% of SA participants as long sleepers. Gut microbial composition analysis (16S rRNA gene sequencing) revealed that bacterial alpha diversity negatively correlated with sleep length (p<0.05). Furthermore, sleep length significantly contributed to the inter-individual beta diversity dissimilarity in gut microbial composition (p<0.01). Participants with both short and long-sleep durations exhibited significantly higher abundances of several taxonomic features, compared to normal sleep duration participants. The predicted relative proportion of two genes involved in the butyrate synthesis via lysine pathway were enriched in short sleep duration participants. Finally, co-occurrence relationships revealed by network analysis showed unique interactions among the short, normal and long duration sleepers. These results suggest that sleep length in humans may alter gut microbiota by driving population shifts of the whole microbiota and also specific changes in Exact Sequence Variants abundance, which may have implications for chronic inflammation associated diseases. The current findings suggest a possible relationship between disrupted sleep patterns and the composition of the gut microbiota. Prospective investigations in larger and more prolonged sleep researches and causally experimental studies are needed to confirm these findings, investigate the underlying mechanism and determine whether improving microbial homeostasis may buffer against sleep-related health decline in humans.
Assuntos
Bactérias/classificação , Microbioma Gastrointestinal/fisiologia , Transtornos do Sono-Vigília/microbiologia , Sono/fisiologia , Adulto , Bactérias/genética , Bactérias/isolamento & purificação , Estudos de Coortes , Fezes/microbiologia , Feminino , Gana , Humanos , Jamaica , Masculino , Pessoa de Meia-Idade , RNA Ribossômico 16S/genética , Análise de Sequência de DNA/métodos , África do Sul , Inquéritos e Questionários , Estados UnidosRESUMO
Long-chain omega-3 PUFAs, specifically eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are of increasing interest because of their favorable effect on cardiometabolic risk. This study explores the association between omega 6 and 3 fatty acids intake and cardiometabolic risk in four African-origin populations spanning the epidemiological transition. Data are obtained from a cohort of 2500 adults aged 25-45 enrolled in the Modeling the Epidemiologic Transition Study (METS), from the US, Ghana, Jamaica, and the Seychelles. Dietary intake was measured using two 24 h recalls from the Nutrient Data System for Research (NDSR). The prevalence of cardiometabolic risk was analyzed by comparing the lowest and highest quartile of omega-3 (EPA+ DHA) consumption and by comparing participants who consumed a ratio of arachidonic acid (AA)/EPA + DHA ≤4:1 and >4:1. Data were analyzed using multiple variable logistic regression adjusted for age, gender, activity, calorie intake, alcohol intake, and smoking status. The lowest quartile of EPA + DHA intake is associated with cardiometabolic risk 2.16 (1.45, 3.2), inflammation 1.59 (1.17, 2.16), and obesity 2.06 (1.50, 2.82). Additionally, consuming an AA/EPA + DHA ratio of >4:1 is also associated with cardiometabolic risk 1.80 (1.24, 2.60), inflammation 1.47 (1.06, 2.03), and obesity 1.72 (1.25, 2.39). Our findings corroborate previous research supporting a beneficial role for monounsaturated fatty acids in reducing cardiometabolic risk.
Assuntos
População Negra , Fatores de Risco Cardiometabólico , Gorduras na Dieta/administração & dosagem , Ácidos Graxos Monoinsaturados/administração & dosagem , Ácidos Graxos Ômega-3/administração & dosagem , Ácidos Graxos Ômega-6/administração & dosagem , Adulto , Fibras na Dieta/administração & dosagem , Ácidos Docosa-Hexaenoicos/administração & dosagem , Ácido Eicosapentaenoico/administração & dosagem , Ácido Eicosapentaenoico/análogos & derivados , Feminino , Gana/epidemiologia , Humanos , Inflamação/epidemiologia , Jamaica/epidemiologia , Masculino , Pessoa de Meia-Idade , Obesidade/epidemiologia , Estudos Prospectivos , Seicheles/epidemiologia , Estados Unidos/epidemiologiaRESUMO
OBJECTIVES: To investigate associations between self-reported sleep duration and cardiometabolic (CM) risk factors in African-origin adults residing in five countries spanning the epidemiologic transition. DESIGN: Cross-sectional. SETTING AND PARTICIPANTS: Ghanaian (nâ¯=â¯491), South African (nâ¯=â¯503), Jamaican (nâ¯=â¯508), Seychellois (nâ¯=â¯501) and American (nâ¯=â¯480) men and women. MEASUREMENTS: Self-reported sleep duration was obtained using questionnaires. Sex- and site-stratified logistic regression analyses investigated relationships between sleep duration, individual CM risk factors and a binary CM risk variable (presence of ≥3 CM risk factors), adjusting for age, physical activity and education. RESULTS: Sleep duration distributions varied by cohort: 44.5%, 41.4%, 35.9%, 16.8% and 2.5% of American, Jamaican, Seychellois, Ghanaian and South African men reported <7â¯h sleep per night respectively (pâ¯<â¯0.001). Similarly, 42.6%, 28.6%, 25.2%, 12.8% and 1.5% of American, Jamaican, Seychellois, Ghanaian and South African women reported <7â¯h sleep respectively (pâ¯<â¯0.001). American men reporting ≤6â¯h sleep were more likely to be in the elevated CM risk group (OR: 2.52, 95%CI: 1.02, 6.22, pâ¯=â¯0.045) and to have a high waist circumference (OR: 2.44, 95%CI: 1.07, 5.57, pâ¯=â¯0.034) compared to those reporting 8â¯h sleep. Jamaican women reporting ≤6â¯h sleep (OR: 2.53, 95%CI: 1.19, 5.36, pâ¯=â¯0.016) and American women reporting 7â¯h sleep (OR: 2.71, 95%CI: 1.17, 6.26, pâ¯=â¯0.002) were more likely to be obese than those reporting 8â¯h sleep. CONCLUSIONS: Associations between short sleep and CM risk factors were only evident in the American men and women and Jamaican women. Future interventions to address CM risk and sleep health may need to be country-specific when targeting high-risk populations.
Assuntos
População Negra/estatística & dados numéricos , Negro ou Afro-Americano/estatística & dados numéricos , Fatores de Risco Cardiometabólico , Síndrome Metabólica/etnologia , Sono , Adulto , Estudos Transversais , Feminino , Gana/epidemiologia , Humanos , Jamaica/epidemiologia , Masculino , Fatores de Risco , Autorrelato , Seicheles/epidemiologia , África do Sul/epidemiologia , Inquéritos e Questionários , Fatores de Tempo , Estados Unidos/epidemiologiaRESUMO
Oral and fecal microbial biomarkers have previously been associated with cardiometabolic (CM) risk, however, no comprehensive attempt has been made to explore this association in minority populations or across different geographic regions. We characterized gut- and oral-associated microbiota and CM risk in 655 participants of African-origin, aged 25-45, from Ghana, South Africa, Jamaica, and the United States (US). CM risk was classified using the CM risk cut-points for elevated waist circumference, elevated blood pressure and elevated fasted blood glucose, low high-density lipoprotein (HDL), and elevated triglycerides. Gut-associated bacterial alpha diversity negatively correlated with elevated blood pressure and elevated fasted blood glucose. Similarly, gut bacterial beta diversity was also significantly differentiated by waist circumference, blood pressure, triglyceridemia and HDL-cholesterolemia. Notably, differences in inter- and intra-personal gut microbial diversity were geographic-region specific. Participants meeting the cut-points for 3 out of the 5 CM risk factors were significantly more enriched with Lachnospiraceae, and were significantly depleted of Clostridiaceae, Peptostreptococcaceae, and Prevotella. The predicted relative proportions of the genes involved in the pathways for lipopolysaccharides (LPS) and butyrate synthesis were also significantly differentiated by the CM risk phenotype, whereby genes involved in the butyrate synthesis via lysine, glutarate and 4-aminobutyrate/succinate pathways and LPS synthesis pathway were enriched in participants with greater CM risk. Furthermore, inter-individual oral microbiota diversity was also significantly associated with the CM risk factors, and oral-associated Streptococcus, Prevotella, and Veillonella were enriched in participants with 3 out of the 5 CM risk factors. We demonstrate that in a diverse cohort of African-origin adults, CM risk is significantly associated with reduced microbial diversity, and the enrichment of specific bacterial taxa and predicted functional traits in both gut and oral environments. As well as providing new insights into the associations between the gut and oral microbiota and CM risk, this study also highlights the potential for novel therapeutic discoveries which target the oral and gut microbiota in CM risk.
Assuntos
Doenças Cardiovasculares/microbiologia , Microbioma Gastrointestinal , Doenças Metabólicas/microbiologia , Boca/microbiologia , Adulto , Doenças Cardiovasculares/epidemiologia , Feminino , Gana/epidemiologia , Humanos , Jamaica/epidemiologia , Masculino , Doenças Metabólicas/epidemiologia , Pessoa de Meia-Idade , Fatores de Risco , África do Sul/epidemiologia , Estados Unidos/epidemiologia , Circunferência da CinturaRESUMO
The greatest burden of cardiovascular disease is now carried by developing countries with cardiometabolic conditions such as metabolic syndrome, obesity and inflammation believed to be the driving force behind this epidemic. Dietary fiber is known to have protective effects against obesity, type 2 diabetes, cardiovascular disease and the metabolic syndrome. Considering the emerging prevalence of these cardiometabolic disease states across the epidemiologic transition, the objective of this study is to explore these associations of dietary fiber with cardiometabolic risk factors in four countries across the epidemiologic transition. We examined population-based samples of men and women, aged 25â»45 of African origin from Ghana, Jamaica, the Seychelles and the USA. Ghanaians had the lowest prevalence of obesity (10%), while Jamaicans had the lowest prevalence of metabolic syndrome (5%) across all the sites. Participants from the US presented with the highest prevalence of obesity (52%), and metabolic syndrome (22%). Overall, the Ghanaians consumed the highest dietary fiber (24.9 ± 9.7 g), followed by Jamaica (16.0 ± 8.3 g), the Seychelles (13.6 ± 7.2 g) and the lowest in the USA (14.2 ± 7.1 g). Consequently, 43% of Ghanaians met the fiber dietary guidelines (14 g/1000 kcal/day), 9% of Jamaicans, 6% of Seychellois, and only 3% of US adults. Across all sites, cardiometabolic risk (metabolic syndrome, inflammation and obesity) was inversely associated with dietary fiber intake, such that the prevalence of metabolic syndrome was 13% for those in the lowest quartile of fiber intake, compared to 9% those in the highest quartile of fiber intake. Notably, twice as many of participants (38%) in the lowest quartile were obese compared to those in the highest quartile of fiber intake (18%). These findings further support the need to incorporate strategies and policies to promote increased dietary fiber intake as one component for the prevention of cardiometabolic risk in all countries spanning the epidemiologic transition.
Assuntos
Doenças Cardiovasculares/epidemiologia , Fibras na Dieta/administração & dosagem , Síndrome Metabólica/epidemiologia , Obesidade/epidemiologia , Adulto , Diabetes Mellitus Tipo 2/epidemiologia , Exercício Físico , Feminino , Gana/epidemiologia , Humanos , Inflamação/epidemiologia , Jamaica/epidemiologia , Masculino , Pessoa de Meia-Idade , Razão de Chances , Fatores de Risco , Seicheles/epidemiologia , Estados Unidos/epidemiologiaRESUMO
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.
Assuntos
População Negra/estatística & dados numéricos , Doenças Cardiovasculares/epidemiologia , Países em Desenvolvimento/estatística & dados numéricos , Desenvolvimento Econômico/estatística & dados numéricos , Adulto , Chicago/epidemiologia , Estudos Epidemiológicos , Europa (Continente) , Feminino , Gana/epidemiologia , Humanos , Jamaica/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , Seicheles/epidemiologia , Fatores Socioeconômicos , África do Sul/epidemiologiaRESUMO
OBJECTIVE: This study examined the association of 25-hydroxyvitamin D [25(OH)D] levels and blood pressure above and below 25(OH)D levels of 20âng/ml in young adults with African ancestry. METHODS: This cross-sectional analysis utilized data from a pooled sample of 2242 adults with African ancestry from five different latitudes (403 in the United States, 474 in South Africa, 479 in Ghana, 448 in Jamaica, and 438 in Seychelles). Piecewise linear regression models with a single knot were fitted to determine above and below a 25(OH)D level of 20âng/ml the slope of SBP and DBP while adjusting for covariates including calcium intake and site. RESULTS: The mean age was 34.4 (6.1) years, and 46.3% were men. Mean SBP and DBP were 118.1 (15.6) and 73.2 (12.2)âmmHg, respectively, and were significantly higher among the United States vs Ghana, Jamaica, and Seychelles groups (Pâ<â0.001 for all comparisons). 25(OH)D levels were significantly lower in the United States vs all other sites (Pâ<â0.001 for all comparisons). When 25(OH)D levels were less than 20âng/ml, slopes of SBP [-0.33 (95% confidence interval (CI) -0.57, -0.07)] and DBP [-0.21 (95% CI -0.40, -0.02)] were negative and significantly different from zero after adjustment for covariates. In contrast, with 25(OH)D levels above 20âng/ml, the slopes of SBP [-0.03 (95% CI -0.13, 0.06)] and DBP [-0.04 (-0.11, 0.03)] did not differ significantly from zero. CONCLUSION: The cross-sectional association of 25(OH)D with blood pressure is strongest when 25(OH)D levels are less than 20âng/ml in young adults with African ancestry.
Assuntos
População Negra , Pressão Sanguínea , Vitamina D/análogos & derivados , Adulto , Estudos Transversais , Feminino , Gana , Humanos , Jamaica , Modelos Lineares , Masculino , Seicheles , África do Sul , Estados Unidos , Vitamina D/sangue , Deficiência de Vitamina D/fisiopatologiaRESUMO
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.
Assuntos
Automóveis/estatística & dados numéricos , População Negra/estatística & dados numéricos , Exercício Físico , Renda , Propriedade , Adulto , Estudos Epidemiológicos , Feminino , Gana , Humanos , Jamaica , Masculino , Pessoa de Meia-Idade , Prevalência , Seicheles , Fatores Socioeconômicos , África do SulRESUMO
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.
Assuntos
Registros de Dieta , Dieta , Ingestão de Energia , Adulto , Índice de Massa Corporal , Doença Crônica , Deutério , Metabolismo Energético , Reações Falso-Negativas , Feminino , Gana , Humanos , Jamaica , Masculino , Rememoração Mental , Pessoa de Meia-Idade , Avaliação Nutricional , Hipernutrição/diagnóstico , Isótopos de Oxigênio , População Rural , Seicheles , África do Sul , Inquéritos e Questionários , Estados Unidos , População Urbana , ÁguaRESUMO
OBJECTIVES: Blood pressures in persons of African descent exceed those of other racial/ethnic groups in the United States. Whether this trait is attributable to the genetic factors in African-origin populations, or a result of inadequately measured environmental exposures, such as racial discrimination, is not known. To study this question, we conducted a multisite comparative study of communities in the African diaspora, drawn from metropolitan Chicago, Kingston, Jamaica, rural Ghana, Cape Town, South Africa, and the Seychelles. METHODS: At each site, 500 participants between the age of 25 and 49 years, with approximately equal sex balance, were enrolled for a longitudinal study of energy expenditure and weight gain. In this study, we describe the patterns of blood pressure and hypertension observed at baseline among the sites. RESULTS: Mean SBP and DBP were very similar in the United States and South Africa in both men and women, although among women, the prevalence of hypertension was higher in the United States (24 vs. 17%, respectively). After adjustment for multiple covariates, relative to participants in the United States, SBP was significantly higher among the South Africans by 9.7âmmHg (Pâ<â0.05) and significantly lower for each of the other sites: for example, Jamaica: -7.9âmmHg (Pâ=â0.06), Ghana: -12.8âmmHg (Pâ<â0.01) and Seychelles: -11.1âmmHg (Pâ=â0.01). CONCLUSION: These data are consistent with prior findings of a blood pressure gradient in societies of the African diaspora and confirm that African-origin populations with lower social status in multiracial societies, such as the United States and South Africa, experience more hypertension than anticipated based on anthropometric and measurable socioeconomic risk factors.
Assuntos
População Negra/estatística & dados numéricos , Pressão Sanguínea , Hipertensão/etnologia , Adulto , Tamanho Corporal , Metabolismo Energético , Estudos Epidemiológicos , Feminino , Gana/epidemiologia , Humanos , Jamaica/epidemiologia , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , População Rural , Seicheles/epidemiologia , Fatores Socioeconômicos , África do Sul/epidemiologia , Estados Unidos/epidemiologiaRESUMO
BACKGROUND: Metals are known endocrine disruptors and have been linked to cardiometabolic diseases via multiple potential mechanisms, yet few human studies have both the exposure variability and biologically-relevant phenotype data available. We sought to examine the distribution of metals exposure and potential associations with cardiometabolic risk factors in the "Modeling the Epidemiologic Transition Study" (METS), a prospective cohort study designed to assess energy balance and change in body weight, diabetes and cardiovascular disease risk in five countries at different stages of social and economic development. METHODS: Young adults (25-45 years) of African descent were enrolled (N = 500 from each site) in: Ghana, South Africa, Seychelles, Jamaica and the U.S.A. We randomly selected 150 blood samples (N = 30 from each site) to determine concentrations of selected metals (arsenic, cadmium, lead, mercury) in a subset of participants at baseline and to examine associations with cardiometabolic risk factors. RESULTS: Median (interquartile range) metal concentrations (µg/L) were: arsenic 8.5 (7.7); cadmium 0.01 (0.8); lead 16.6 (16.1); and mercury 1.5 (5.0). There were significant differences in metals concentrations by: site location, paid employment status, education, marital status, smoking, alcohol use, and fish intake. After adjusting for these covariates plus age and sex, arsenic (OR 4.1, 95% C.I. 1.2, 14.6) and lead (OR 4.0, 95% C.I. 1.6, 9.6) above the median values were significantly associated with elevated fasting glucose. These associations increased when models were further adjusted for percent body fat: arsenic (OR 5.6, 95% C.I. 1.5, 21.2) and lead (OR 5.0, 95% C.I. 2.0, 12.7). Cadmium and mercury were also related with increased odds of elevated fasting glucose, but the associations were not statistically significant. Arsenic was significantly associated with increased odds of low HDL cholesterol both with (OR 8.0, 95% C.I. 1.8, 35.0) and without (OR 5.9, 95% C.I. 1.5, 23.1) adjustment for percent body fat. CONCLUSIONS: While not consistent for all cardiometabolic disease markers, these results are suggestive of potentially important associations between metals exposure and cardiometabolic risk. Future studies will examine these associations in the larger cohort over time.
Assuntos
Arsênio/sangue , Peso Corporal/efeitos dos fármacos , Doenças Cardiovasculares/epidemiologia , Diabetes Mellitus/epidemiologia , Exposição Ambiental , Poluentes Ambientais/sangue , Metais Pesados/sangue , Adulto , África/epidemiologia , Biomarcadores , Doenças Cardiovasculares/induzido quimicamente , Chicago/epidemiologia , Diabetes Mellitus/induzido quimicamente , Feminino , Humanos , Jamaica/epidemiologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de RiscoRESUMO
BACKGROUND: This difference in how populations living in low-, middle or upper-income countries accumulate daily PA, i.e. patterns and intensity, is an important part in addressing the global PA movement. We sought to characterize objective PA in 2,500 participants spanning the epidemiologic transition. The Modeling the Epidemiologic Transition Study (METS) is a longitudinal study, in 5 countries. METS seeks to define the association between physical activity (PA), obesity and CVD risk in populations of African origin: Ghana (GH), South Africa (SA), Seychelles (SEY), Jamaica (JA) and the US (suburban Chicago). METHODS: Baseline measurements of objective PA, SES, anthropometrics and body composition, were completed on 2,500 men and women, aged 25-45 years. Moderate and vigorous PA (MVPA, min/d) on week and weekend days was explored ecologically, by adiposity status and manual labor. RESULTS: Among the men, obesity prevalence reflected the level of economic transition and was lowest in GH (1.7%) and SA (4.8%) and highest in the US (41%). SA (55%) and US (65%) women had the highest levels of obesity, compared to only 16% in GH. More men and women in developing countries engaged in manual labor and this was reflected by an almost doubling of measured MPVA among the men in GH (45 min/d) and SA (47 min/d) compared to only 28 min/d in the US. Women in GH (25 min/d), SA (21 min/d), JA (20 min/d) and SEY (20 min/d) accumulated significantly more MPVA than women in the US (14 min/d), yet this difference was not reflected by differences in BMI between SA, JA, SEY and US. Moderate PA constituted the bulk of the PA, with no study populations except SA men accumulating > 5 min/d of vigorous PA. Among the women, no sites accumulated >2 min/d of vigorous PA. Overweight/obese men were 22% less likely to engage in manual occupations. CONCLUSION: While there is some association for PA with obesity, this relationship is inconsistent across the epidemiologic transition and suggests that PA policy recommendations should be tailored for each environment.
Assuntos
Países Desenvolvidos , Países em Desenvolvimento , Exercício Físico , Obesidade/prevenção & controle , Esforço Físico , Trabalho , Adiposidade , Adulto , Índice de Massa Corporal , Chicago/epidemiologia , Feminino , Gana/epidemiologia , Humanos , Jamaica/epidemiologia , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Atividade Motora , Obesidade/epidemiologia , Obesidade/etiologia , Ocupações , Sobrepeso , Fatores Sexuais , Seicheles/epidemiologia , África do Sul/epidemiologia , Fatores de TempoRESUMO
BACKGROUND: Patients with sickle cell disease in the USA have been noted to have lower levels of vitamin D - measured as 25-hydroxyvitamin D (25(OH)D) - compared to controls. Average serum 25(OH)D levels are also substantially lower in African Americans than whites, while population distributions of 25(OH)D among Jamaicans of African descent and West Africans are the same as among USA whites. The purpose of this study was to examine whether adult patients with sickle cell disease living in tropical regions had reduced 25(OH)D relative to the general population. METHODS: We analyzed serum 25(OH)D in stored samples collected from studies in Jamaica and West Africa of adult patients with sickle cell disease and adult population controls. RESULTS: In samples of 20 Jamaicans and 50 West Africans with sickle cell disease mean values of 25(OH)D were 37% and 39% lower than controls, respectively. Metabolic abnormalities in the absorption and conversion pathways are possible causes for the consistent relative deficiency of 25(OH)D in sickle cell disease. CONCLUSIONS: Low 25(OH)D levels in tropical Africa where the burden of sickle cell disease is highest, deserve further investigation, and a randomized trial is warranted to address efficacy of supplementation.
RESUMO
BACKGROUND: The vitamin D-endocrine system is thought to play a role in physiologic processes that range from mineral metabolism to immune function. Serum 25-hydroxyvitamin D [25(OH)D] is the accepted biomarker for vitamin D status. Skin color is a key determinant of circulating 25(OH)D concentrations, and genes responsible for melanin content have been shown to be under strong evolutionary selection in populations living in temperate zones. Little is known about the effect of latitude on mean concentrations of 25(OH)D in dark-skinned populations. OBJECTIVE: The objective was to describe the distribution of 25(OH)D and its subcomponents in 5 population samples of African origin from the United States, Jamaica, Ghana, South Africa, and the Seychelles. DESIGN: Participants were drawn from the Modeling of the Epidemiologic Transition Study, a cross-sectional observational study in 2500 adults, ages 25-45 y, enrolled between January 2010 and December 2011. Five hundred participants, â¼50% of whom were female, were enrolled in each of 5 study sites: Chicago, IL (latitude: 41°N); Kingston, Jamaica (17°N); Kumasi, Ghana (6°N); Victoria, Seychelles (4°S); and Cape Town, South Africa (34°S). All participants had an ancestry primarily of African origin; participants from the Seychelles trace their history to East Africa. RESULTS: A negative correlation between 25(OH)D and distance from the equator was observed across population samples. The frequency distribution of 25(OH)D in Ghana was almost perfectly normal (Gaussian), with progressively lower means and increasing skewness observed at higher latitudes. CONCLUSIONS: It is widely assumed that lighter skin color in populations outside the tropics resulted from positive selection, driven in part by the relation between sun exposure, skin melanin content, and 25(OH)D production. Our findings show that robust compensatory mechanisms exist that create tolerance for wide variation in circulating concentrations of 25(OH)D across populations, suggesting a more complex evolutionary relation between skin color and the vitamin D pathway.
Assuntos
25-Hidroxivitamina D 2/sangue , Calcifediol/sangue , Modelos Biológicos , Pigmentação da Pele , Pele/efeitos da radiação , Raios Ultravioleta , Deficiência de Vitamina D/epidemiologia , 25-Hidroxivitamina D 2/metabolismo , Adulto , Biomarcadores/sangue , População Negra , Calcifediol/análogos & derivados , Calcifediol/metabolismo , Chicago/epidemiologia , Estudos Transversais , Feminino , Gana/epidemiologia , Humanos , Jamaica/epidemiologia , Masculino , Pessoa de Meia-Idade , Risco , Seicheles/epidemiologia , Pele/metabolismo , África do Sul/epidemiologia , Luz Solar , Deficiência de Vitamina D/sangue , Deficiência de Vitamina D/metabolismoRESUMO
We longitudinally explored the relationship of body size and adiponectin levels in 393 community-dwelling Afro-Jamaicans. Adiponectin levels were greater in women, increased with age and declined with abdominal adiposity. Multivariate regression analyses suggest that subcutaneous fat in women may contribute significantly to the variance in their adiponectin levels.
Assuntos
Adiponectina/sangue , Tecido Adiposo/anatomia & histologia , População Negra/estatística & dados numéricos , Distribuição da Gordura Corporal , Adulto , Idoso , Estatura , Peso Corporal , Feminino , Humanos , Resistência à Insulina , Jamaica , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Análise de Regressão , Caracteres Sexuais , População UrbanaRESUMO
Genome-wide association (GWA) studies have identified common variants that are associated with a variety of traits and diseases, but most studies have been performed in European-derived populations. Here, we describe the first genome-wide analyses of imputed genotype and copy number variants (CNVs) for anthropometric measures in African-derived populations: 1188 Nigerians from Igbo-Ora and Ibadan, Nigeria, and 743 African-Americans from Maywood, IL. To improve the reach of our study, we used imputation to estimate genotypes at approximately 2.1 million single-nucleotide polymorphisms (SNPs) and also tested CNVs for association. No SNPs or common CNVs reached a genome-wide significance level for association with height or body mass index (BMI), and the best signals from a meta-analysis of the two cohorts did not replicate in approximately 3700 African-Americans and Jamaicans. However, several loci previously confirmed in European populations showed evidence of replication in our GWA panel of African-derived populations, including variants near IHH and DLEU7 for height and MC4R for BMI. Analysis of global burden of rare CNVs suggested that lean individuals possess greater total burden of CNVs, but this finding was not supported in an independent European population. Our results suggest that there are not multiple loci with strong effects on anthropometric traits in African-derived populations and that sample sizes comparable to those needed in European GWA studies will be required to identify replicable associations. Meta-analysis of this data set with additional studies in African-ancestry populations will be helpful to improve power to detect novel associations.
Assuntos
População Negra/genética , Negro ou Afro-Americano/genética , Variações do Número de Cópias de DNA , Estudo de Associação Genômica Ampla , Adolescente , Adulto , Idoso , Antropometria , Genótipo , Humanos , Illinois , Jamaica , Pessoa de Meia-Idade , Modelos Estatísticos , Nigéria , Polimorfismo de Nucleotídeo Único , Adulto JovemRESUMO
OBJECTIVES: Adiponectin and ghrelin are associated with adiposity and type 2 diabetes in several studies. We sought to prospectively determine the interaction of adiponectin and ghrelin in the development of adiposity and hyperglycaemia. DESIGN: Prospective observational study. PARTICIPANTS: 393 community-dwelling Afro-Jamaicans (mean age 47 +/- 13 years; BMI 27.3 +/- 6.3 kg/m(2); 63% women) without glucose intolerance at baseline. MEASUREMENTS: Anthropometry, fasting plasma glucose, 2-h plasma glucose, insulin resistance (HOMA-IR), adiponectin and ghrelin concentrations were measured at baseline and 4.1 +/- 0.9 years later. Multivariate analyses were used to explore the associations of HOMA-IR, adiponectin and ghrelin with weight change and glycaemia. Results The mean weight change was 2.6 +/- 5.5 kg. There were 114 incident cases of impaired glucose tolerance (IGT) and 35 cases of diabetes mellitus. Adiponectin was positively correlated with age and female sex (P-values < 0.01). After adjusting for age and sex, adiponectin and ghrelin were significantly correlated with weight at baseline and follow-up. However, they were not associated with weight change even after further adjustment for baseline weight. Adiponectin, but not ghrelin, was associated with 2-h glucose concentrations at follow-up even after adjusting for age, sex, HOMA-IR and BMI (P = 0.04). In the fully adjusted logistic regression model, adiponectin predicted incident IGT (OR 0.93; 95% CI: 0.87-0.99) and attenuated the effect of BMI on incident IGT. CONCLUSIONS: These longitudinal data show that adiponectin and ghrelin may not be causally involved in the development of obesity. However, adiponectin is independently associated with decreased risk of incident IGT.
Assuntos
Adiponectina/sangue , Adiposidade/fisiologia , Grelina/sangue , Intolerância à Glucose/fisiopatologia , Aumento de Peso/fisiologia , Adulto , Idoso , População Negra/etnologia , Glicemia/metabolismo , Feminino , Seguimentos , Intolerância à Glucose/etnologia , Humanos , Hiperglicemia/fisiopatologia , Resistência à Insulina/fisiologia , Jamaica , Modelos Logísticos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Estudos ProspectivosRESUMO
BACKGROUND: Angiotensin I-converting enzyme (ACE) plays an important role in cardiovascular homeostasis. There is evidence from different ethnic groups that circulating ACE levels are influenced by a quantitative trait locus (QTL) at the ACE gene on chromosome 17. The finding of significant residual familial correlations in different ethnic groups, after accounting for this QTL, and the finding of support for linkage to a locus on chromosome 4 in Mexican-American families strongly suggest that there may well be QTLs for ACE unlinked to the ACE gene. METHODS: A genome-wide panel of microsatellite markers, and a panel of biallelic polymorphisms in the ACE gene were typed in Nigerian families. Single locus models with fixed parameters were used to test for linkage to circulating ACE with and without adjustment for the effects of the ACE gene polymorphisms. RESULTS: Strong evidence was found for D17S2193 (Zmax = 3.5); other nearby markers on chromosome 17 also showed modest support. After adjustment for the effects of the ACE gene locus, evidence of "suggestive linkage" to circulating ACE was found for D4S1629 (Zmax = 2.2); this marker is very close to a locus previously shown to be linked to circulating ACE levels in Mexican-American families. CONCLUSION: In this report we have provided further support for the notion that there are QTLs for ACE unlinked to the ACE gene; our findings for chromosome 4, which appear to replicate the findings of a previous independent study, should be considered strong grounds for a more detailed examination of this region in the search for genes/variants which influence ACE levels.The poor yields, thus far, in defining the genetic determinants of hypertension risk suggest a need to look beyond simple relationships between genotypes and the ultimate phenotype. In addition to incorporating information on important environmental exposures, a better understanding of the factors which influence the building blocks of the blood pressure homeostatic network is also required. Detailed studies of the genetic determinants of ACE, an important component of the renin-angiotensin system, have the potential to contribute to this strategic objective.
RESUMO
We assessed activity energy expenditure (AEE) in Mexican-American (MA) and European-American (EA) children. Total energy expenditure (TEE) was measured using the doubly-labeled water method; AEE was calculated as the difference between TEE and resting EE (REE), and physical activity level (PAL) was calculated as TEE/REE. Groups were comparable for age, sex and body mass index (BMI). REE did not differ between groups. The boys did not differ in TEE, AEE, or PAL (MA vs. EA, respectively: TEE, 7.9+/-1.5 vs. 7.5+/-0.9 MJ x d(-1); AEE: 64.9+/-24.7 vs. 65.3+/-22.3 kJ x kg(-1) x d(-1); PAL: 1.57+/-0.18 vs. 1.58+/-0.19 kJ x kg(-1) x d(-1)). MA girls had lower TEE, AEE, and PAL than EA girls (TEE: 6.8+/-0.9 vs. 8.1+/-0.8 MJ x d(-1); AEE, 37.3+/-15.9 vs. 64.9+/-24.7 kJ x kg(-1) x d(-1); PAL, 1.40+/-0.12 vs. 1.57+/-0.18; P <0.005). Results suggest that these MA girls were expending less energy than EA children of comparable body size due to a reduced activity energy expenditure.