Insulin Resistance In Semi-Urban South Western Nigeria And It’s Relationship With Indices Of Obesity

Abstract

The International Diabetes Federation (IDF) estimates that currently more than 246 million people have diabetesworldwide, and this figure is expected to reach 380 million by 2030. Although insulin resistance is a modifiableprecursor of diabetes and potentially of cardiovascular disease, there are scanty reports on its prevalence inNigeria. The aim of this study was to determine the prevalence of insulin resistance and its relationship withindices of obesity in a semi urban Nigeria. Fifty subjects with no prior history of hypertension or diabetes mellituswere evaluated for insulin resistance using the homeostasis model assessment (HOMA) method. The bloodpressure and the anthropometric parameters of the subjects were measured, and fasting plasma glucose andinsulin determined. Insulin resistance was defined at two levels of HOMA scores: score >1 and score >2 and itscorrelation with waist circumference, body mass index and waist to hip ratio were determined. When insulinresistance was defined as HOMA score >1, the prevalence of insulin resistance was 29.2% in males and 53.8% infemales (p>0.05), with a combined prevalence of 42%. When insulin resistance was taken as HOMA score >2 thefemales were significantly more resistant to insulin than the males (females 38.5% vs 12.5%, p <0.05), and thecombined prevalence was 26%. There was positive but weak correlation between the anthropometric indices andinsulin resistance. The correlation between insulin resistance and the anthropometric indices was best with waistcircumference, while it was least with waist-to-hip ratio (0.181 vs. 0.081). Of the three indices of obesity, waistcircumference contributed most to HOMA-IR. Insulin resistance is common in the South Western Nigerianpopulation studied, and insulin resistance was more prevalent among the female than male participants. Therewas a positive but weak correlation between insulin resistance and anthropometric indices.Key Words: insulin resistance, HOMA-IR, obesity