Deriving an optimal threshold of waist circumference for detecting cardiometabolic risk in sub-Saharan Africa

Publication Date: 
Tuesday, October 3, 2017
31. Ekoru K, Murphy GAV, Young EH, Delisle H, Jerome CS, Assah F, Longo-Mbenza B, Nzambi JPD, On'Kin JBK, Buntix F, Muyer MC, Christensen DL, Wesseh CS, Sabir A, Okafor C, Gezawa ID, Puepet F, Enang O, Raimi T, Ohwovoriole E, Oladapo OO, Bovet P, Mollentze W, Unwin N, Gray WK, Walker R, Agoudavi K, Siziya S, Chifamba J, Njelekela M, Fourie CM, Kruger S, Schutte AE, Walsh C, Gareta D, Kamali A, Seeley J, Norris SA, Crowther NJ, Pillay D, Kaleebu P, Motala AA, Sandhu MS

BACKGROUND:
Waist circumference (WC) thresholds derived from western populations continue to be used in sub-Saharan Africa (SSA) despite increasing evidence of ethnic variation in the association between adiposity and cardiometabolic disease and availability of data from African populations. We aimed to derive a SSA-specific optimal WC cut-point for identifying individuals at increased cardiometabolic risk.

METHODS:
We used individual level cross-sectional data on 24 181 participants aged ⩾15 years from 17 studies conducted between 1990 and 2014 in eight countries in SSA. Receiver operating characteristic curves were used to derive optimal WC cut-points for detecting the presence of at least two components of metabolic syndrome (MS), excluding WC.

RESULTS:
The optimal WC cut-point was 81.2 cm (95% CI 78.5-83.8 cm) and 81.0 cm (95% CI 79.2-82.8 cm) for men and women, respectively, with comparable accuracy in men and women. Sensitivity was higher in women (64%, 95% CI 63-65) than in men (53%, 95% CI 51-55), and increased with the prevalence of obesity. Having WC above the derived cut-point was associated with a twofold probability of having at least two components of MS (age-adjusted odds ratio 2.6, 95% CI 2.4-2.9, for men and 2.2, 95% CI 2.0-2.3, for women).

CONCLUSION:
The optimal WC cut-point for identifying men at increased cardiometabolic risk is lower (⩾81.2 cm) than current guidelines (⩾94.0 cm) recommend, and similar to that in women in SSA. Prospective studies are needed to confirm these cut-points based on cardiometabolic outcomes.International Journal of Obesity advance online publication, 31 October 2017; doi:10.1038/ijo.2017.240.

Publisher: 
Int J Obes (Lond)