ANTHROPOMETRIC PARAMETERS AS HELPFUL FACTORS FOR PREDICTION OF TYPE 2 DIABETES ONSET, TEHRAN LIPID AND GLUCOSE STUDY

The aim of this study was to determine the best Anthropometric indices for prediction of the risk of type 2 Diabetes in lower and higher 60 years old population in Tehran. As a prospective study among 4479 non-diabetic men and women over 20 years from the participants of Tehran Lipid and Glucose Study (TLGS) who had complete data of blood pressure, plasma glucose in the fasting state and 2 hours after ingestion of 75 g glucose (2-hPG) as well as fasting serum lipids, anthropometric measurement including body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR) and demographic data at baseline and were followed for a mean duration of 3.6 years. Subjects reevaluated for measurement of fasting Glucose and 2-hPG at follow-up. Diabetes and its associated risk factors were defined according to the ADA criteria. Different measurements of general and central obesity were defined based on the WHO criteria. Logistic regression analysis with stepwise conditional method was used to estimate the Odds Ratio (OR) with 95% CI. A total of 166 new cases of type 2 diabetes (3.7%) were diagnosed during 3.6 years of follow-up, with an approximately one percent per year incidence rate (men=3.7% and women =3.7%, P= 0.95). Diabetic subjects of follow-up were significantly more obese than nondiabetics considering their BMI, WC and WHR. In subjects aged< 60 years high WC was a predictor of diabetes only in model 1 and 2, while general obesity and high WHR predicted diabetes risk in all the 3 models. In these 3 models the OR of general obesity were 5.3(2.9-9.5), 3.4(1.8-6.3), 2.4(1.1-5.1) and the OR of high WHR were 3.5(2.1-5.8), 3.4(1.4-5.8) and 2.6(1.3-4.9), respectively. In subjects aged≥ 60 years general obesity predicted diabetes only in models 1 and 2, while high WHR was a predictor of diabetes risk only in model 1. In this age group, high WC predicted diabetes in all models 1, 2, 3 with the OR of 4.6 (2.3-4.1), 4.5 (2.3-8.9) and 3.8 (1.8-7.7), respectively. General obesity and high WHR in young Iranian subjects (< 60years) and high WC in older ones (≥ 60 years) are the important anthropometric indices for prediction of type 2 diabetes. Age should be considered when using different anthropometric indices for predicting the risk of type 2 diabetes.