Anthropometric indices: How they compare in screening of cardio- metabolic risks in a Nigerian sub-population

The current anthropometric indices used for diagnosis of cardio-metabolic syndrome (CMS) in sub-Saharan Africa are those widely validated in the western world. We hereby aim to compare the sensitivity and specificity of these tools in identifying risk factors for CMS.

The study assessed body mass index (BMI), waist circumference (WC) and waist-to-height ratio (WHtR). Statistical analyses were performed to determine the sensitivity and specificity of WHtR in comparison with WC cut-off points recommended by the International Diabetes Federation (IDF) and the Third Adult Treatment Panel (ATPIII) as well as BMI cut-offs prescribed by the World Health Organisation (WHO).

WHtR had the highest area under the receiver operating characteristic (ROC) curve in screening CMS. WHtR >0.5 also showed highest sensitivity in both genders in identifying CMS and clusters of >2 CMS risk factors, but with lowest specificity and positive likelihood ratio (LR+). ATPIII WC cut-off revealed lowest sensitivity and highest specificity in screening CMS and >2 CMS risk factors in males (p<0.000l). IDF WC-threshold had the more stable sensitivity and specificity in males (p<0.0001) but not in females.

WHtR>0.5 is more sensitive than WC and BMI recommended values in screening for CMS, but with the least positive likelihood ratio. However, more studies in other nations of sub-Saharan Africa are needed to assure evaluation of different cut points that will yield optimal specificity and sensitivity. This will help curb the problem of over-diagnosis of CMS risk factors and increase better health outcome of the population.