Waist Circumference as a Measure of Insulin Resistance/Pre-diabetes in KwaZulu-Natal, South Africa: Implications for Forestalling Type 2 Diabetes

Abstract

Background. The World Health Organization reports a grim picture of the type 2 diabetes mellitus (T2DM) epidemic with sub-Saharan Africa bearing the brunt of this outbreak and South Africa is at the forefront. In South Africa, T2DM accounts for 58 deaths per day and is the fifth highest cause of death. Central to this alarming T2DM epidemic is the overweight and obesity tsunami that can be prevented. The purpose of this study was to determine whether the waist circumference cutoff for overweight proposed by the International Diabetes Federation (IDF) are applicable to KwaZulu-Natal in monitoring overweight/obesity in rural and economically disadvantaged communities. Design and methods. Two hundred and forty nine nondiabetic adult subjects attending community health centers in KwaZulu-Natal Province who had not eaten any breakfast participated in the study. Anthropometric measures were done under trained supervision. Blood samples were collected for estimation of fasting insulin and fasting blood glucose levels. The following surrogate measures of insulin resistance were used: Homeostasis model assessment of insulin resistance (HOMA-IR) and Quantitative Insulin sensitivity Check Index (QUICKI. Anthropometric measurements were also taken. Results. The mean waist circumference for both men and women was well above the cutoffs recommended by the IDF. The weight range for men was 47 -133 kg and for women 44 -180 kg. The BMI ranges were 15- 40 for men and 18 – 75 for women. Individuals with waist circumference above the IDF- recommended cutoffs were insulin resistant based on the surrogate indices of insulin resistance. Conclusions. The epidemic of overweight and obesity is indeed a tsunami in this study population of KwaZulu-Natal and we appeal for implementation of educational campaigns to encourage people to monitor their weight gain by simply measuring waist circumference using regular and easily affordable tape measures.