Browsing by Author "Durazo-Arvizu, Ramon"

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    Association between smoking and total energy expenditure in a multi-country study
    (2014-10-04) Gonseth, Semira; Dugas, Lara; Viswanathan, Barathi; Forrester, Terrence; Lambert, Vicki; Plange-Rhule, Jacob; Durazo-Arvizu, Ramon; Luke, Amy; Schoeller, Dale A; Bovet, Pascal
    Abstract Background The association between smoking and total energy expenditure (TEE) is still controversial. We examined this association in a multi-country study where TEE was measured in a subset of participants by the doubly labeled water (DLW) method, the gold standard for this measurement. Methods This study includes 236 participants from five different African origin populations who underwent DLW measurements and had complete data on the main covariates of interest. Self-reported smoking status was categorized as either light (andlt;7 cig/day) or high (and#8805;7 cig/day). Lean body mass was assessed by deuterium dilution and physical activity (PA) by accelerometry. Results The prevalence of smoking was 55% in men and 16% in women with a median of 6.5 cigarettes/day. There was a trend toward lower BMI in smokers than non-smokers (not statistically significant). TEE was strongly correlated with fat-free mass (men: 0.70; women: 0.79) and with body weight (0.59 in both sexes). Using linear regression and adjusting for body weight, study site, age, PA, alcohol intake and occupation, TEE was larger in high smokers than in never smokers among men (difference of 298and#160;kcal/day, pand#8201;=and#8201;0.045) but not among women (162and#160;kcal/day, pand#8201;=and#8201;0.170). The association became slightly weaker in men (254and#160;kcal/day, pand#8201;=and#8201;0.058) and disappeared in women (and#8722;76and#160;kcal/day, pand#8201;=and#8201;0.380) when adjusting for fat-free mass instead of body weight. Conclusion There was an association between smoking and TEE among men. However, the lack of an association among women, which may be partly related to the small number of smoking women, also suggests a role of unaccounted confounding factors.
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    Vitamin D levels are low in adult patients with sickle cell disease in Jamaica and West Africa
    (2014-08-16) Tayo, Bamidele O; Akingbola, Titilola S; Salako, Babatunde L; McKenzie, Colin A; Reid, Marvin; Layden, Jennifer; Osunkwo, Ifeyinwa; Plange-Rhule, Jacob; Luke, Amy; Durazo-Arvizu, Ramon; Cooper, Richard S
    Abstract Background Patients with sickle cell disease in the USA have been noted to have lower levels of vitamin D and#8211; measured as 25-hydroxyvitamin D (25(OH)D) and#8211; 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.