Measures of general and central obesity and risk of type 2 diabetes in a Ghanaian population

Abstract

Objective: The epidemic of obesity and type 2 diabetes is evident in sub-Saharan Africa (SSA). However, their associations have hardly been examined in this region.

Methods: A hospital-based case-control study in urban Ghana consisting of 1221 adults (542 cases and 679 controls) investigated the role of anthropometric parameters for diabetes. Logistic regression was used for analysis. The discriminative power and population-specific cut-off points for diabetes were identified by receiver operating characteristic curves.

Results: The strongest association with diabetes was observed for waist-to-hip ratio: age-adjusted odds ratios per 1 standard deviation difference were 1.95 (95% confidence interval [CI]: 1.64-2.31) in women and 1.40 [1.01-1.94] in men. Also, among women, the odds of diabetes increased with higher waist circumference (1.35 [1.17-1.57]) and waist-to-height ratio (1.29 [1.12-1.50]). Among men, this was not discernible. Rather, hip circumference was inversely related (0.69 [0.50-0.95]). Body mass index was neither associated with diabetes in women (1.01 [0.88-1.15]) nor in men (0.74 [0.52-1.04]). Among both genders, waist-to-hip ratio showed the best discriminative ability for diabetes in this population and the optimal cut-off points were ≥ 0.88 in women and ≥ 0.90 in men. Recommended cut-off points for body mass index and waist circumference had a poor predictive ability.

Conclusion: Our findings suggest that measures of central rather than general obesity relate to type 2 diabetes in SSA. It remains to be verified from larger population-based epidemiological studies whether anthropometric targets of obesity prevention in SSA differ from those in developed countries.