Abdominal obesity and insulin resistance in patients with type 2 diabetes in a Swedish community -: Skaraborg Hypertension and Diabetes Project

Objective. To explore the association between abdominal obesity and insulin resistance in patients with type 2 diabetes. Design. A cross-sectional observational study. Setting. Primary care in Skara, Sweden. Subjects. A total of 198 men and 186 women with type 2 diabetes who consecutively completed an annual check-up in 1992-1993. Main outcome measures. Abdominal obesity was defined according to criteria for the metabolic syndrome using the waist circumference (WC): > 102 cm for men and > 88 cm for women. Insulin resistance was estimated using the Homeostasis Model Assessment (HOMA), and was dichotomized by the 75th percentile (IR). Results. Abdominal obesity was found in 66 men (33%), and in 106 women (57%). Pearson's correlation coefficients between components of the metabolic syndrome and IR were statistically significant for WC, waist-hip ratio, serum triglycerides, and HDL cholesterol, and were higher for WC (0.40) than for waist-hip ratio (0.23) in both genders (p < 0.001). The association between WC and IR was challenged by successively entering other components of the metabolic syndrome into the model in a logistic regression. In the final model, adjusting for differences in age, systolic blood pressure, HbA1c, serum triglycerides, HDL cholesterol, and microalbuminuria, the association remained statistically significant both in men (OR 8.6, 95% CI 3.0-25.2, p < 0.001), and in women (OR 5.6, 95% CI 1.7-18.1, p = 0.004). Conclusions. WC provides a feasible measure for insulin resistance in the vast majority of subjects with type 2 diabetes. It is convenient and less expensive than direct means and could be used as a proxy for insulin resistance in population studies.