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PURPOSE: Waist circumference (WC) and waist-to-height ratio (WHtR) are widely used as indicators of abdominal adiposity and the cut-off values have been validated primarily in Caucasians. In this study we identified the WC and WHtR cut-off points that best predicted cardiometabolic risk (CMR) in groups of African (Benin) and African ancestry (Haiti) Black subjects. METHODS: This cross-sectional study included 452 apparently healthy subjects from Cotonou (Benin) and Port-au-Prince (Haiti), 217 women and 235 men from 25 to 60 years. CMR biomarkers were the metabolic syndrome components. Additional CMR biomarkers were a high atherogenicity index (total serum cholesterol/high density lipoprotein cholesterol ≥4 in women and ≥5 in men); insulin resistance set at the 75th percentile of the calculated Homeostasis Model Assessment index (HOMA-IR); and inflammation defined as high-sensitivity C-reactive protein (hsCRP) concentrations between 3 and 10 mg/L. WC and WHtR were tested as predictors of two out of the three most prevalent CMR biomarkers. Receiver operating characteristic (ROC) curves, Youden's index, and likelihood ratios were used to assess the performance of specific WC and WHtR cut-offs. RESULTS: High atherogenicity index (59.5%), high blood pressure (23.2%), and insulin resistance (25% by definition) were the most prevalent CMR biomarkers in the study groups. WC and WHtR were equally valid as predictors of CMR. Optimal WC cut-offs were 80 cm and 94 cm in men and women, respectively, which is exactly the reverse of the generic cut-offs. The standard 0.50 cut-off of WHtR appeared valid for men, but it had to be increased to 0.59 in women. CONCLUSION: CMR was widespread in these population groups. The present study suggests that in order to identify Africans with high CMR, WC thresholds will have to be increased in women and lowered in men. Data on larger samples are needed.
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INTRODUCTION: Elevated circulating homocysteine (Hcy) is considered as an independent cardiovascular disease risk factor. Hyperhomocysteinaemia (HHcy) is influenced by nutritional, genetic, and environmental factors. The purpose of the study was to assess HHcy prevalence in Benin, its association with intakes of B-vitamins (B2, B6, B9, B12), alcohol intake, and socio-economic status (SES), and its links with other factors of cardio-metabolic risk. METHODS: The cross-sectional study included 541 apparently healthy subjects, aged 25 to 65 years, from three sites: the main city, a small city and a rural area. Hcy was measured with an ELISA test kit. The HHcy cut-off was 12 µmol/L. Dietary intake was assessed with three 24-hour recalls. We used a structured questionnaire to assess alcohol consumption, demographics, and SES according to education and an amenity score as income proxy. Criteria for obesity, hypertension, dyslipidemia and hyperglycemia were primarily those of World Health Organization (WHO) and the International Diabetes Federation. RESULTS: Mean age was 38.1 ± 10.1 years. The prevalence of HHcy was 52.2% in men and 24.7% in women. In multiple linear regression models, Hcy in men was positively associated with alcohol intake, but only alcohol in beer. In women, Hcy was negatively related to vitamin B12 intake. According to multivariate models of cardio-metabolic risk factors, HHcy was associated in women with more than twice the odds of hypertension and with high TC/HDL-c ratio. In men, Hcy was positively and independently associated with diastolic blood pressure and with LDL-cholesterol and total cholesterol in linear regression models. DISCUSSION: The prevalence of HHcy is high in Benin, when compared with other studies, and it was as expected higher in men than in women. Elevated Hcy was associated with inadequate intake of vitamin B12 in women, whereas alcohol consumption and its negative correlation with B12 intake was also involved in men. Although HHcy was independently associated with hypertension (in women) and more adverse cholesterol profile, no inference can be made because of the cross-sectional design of the study.