Objective: To study the features and specificity of body fat depot abnormalities in type 2 diabetic patients.
Methods: 366 Chinese aged >or= 40, 287 with type 2 diabetics and 79 without type 2 diabetics, hypertension and dyslipidemia, underwent the following examinations: (1) total body fat depots, defined by body mass index (BMI); (2) regional body fat depots, including waist circumference (W), hip circumference (H), femoral circumference (F), intra-abdominal fat area (VA), abdominal subcutaneous fat area (SA) and femoral subcutaneous fat area (FA); (3) ratio between regional and body fat depots (W/BMI, H/BMI, F/BMI, VA/BMI, SA/BMI and FA/BMI); (4) body fat distribution, including W and H ratio (WHR), W and F ratio (WFR), VA + SA/FA, and VA/SA; and (5) tissue insulin sensitivity, expressed by homeostasis model assessment index for insulin resistance (HOMA-IR).
Results: The body fat depot abnormalities observed in type 2 diabetes were as follows: (1) increase in total body fat depots (BMI) (P = 0.0013); (2) increase in abdominal fat depots (W) (P < 0.0001), mainly accounted for absolute and relative increases in intra-abdominal fat depots (VA, VA/SA and VA/BMI) P = 0.0011, 0.0025, 0.0008 respectively; (3) relative decrease in hip and femoral subcutaneous fat depots (H/BMI, F/BMI and FA/BMI) (P < 0.0001, < 0.00001, = 0.0014 respectively); (4) central distribution of body fat (WHR, WFR and VA + SA/FA) (P < 0.0001, = 0.0002, = 0.0002 respectively) by increase in intra-abdominal fat depots as well as decrease in hip or femoral body fat depots. The degree of abnormalities in body fat depots and the degree of tissue insulin resistance were in parallel with the number of other metabolic diseases (hypertension and dyslipidemia) associated in type 2 diabetic patients. Stepwise regression analysis indicated that increase in total body fat depots was the major independent contibuting factor for tissue insulin resistance. Moreover, increase in intra-abdominal fat depots and decrease in femoral fat depots were also independent contributing factors for insulin resistance.
Conclusion: Increase in intra-abdominal fat depots as well as decrease in femoral subcutaneous fat depots is not only the features of body fat distribution observed in diabetic patients, but also in subjects with metabolic syndrome.