Involvement of visceral fat in the pathogenesis of albuminuria in patients with type 2 diabetes with early stage of nephropathy

Visceral obesity has been implicated in the pathogenesis of diabetic nephropathy. Waist circumference has been used as a surrogate measure of visceral fat mass; however, subcutaneous fat mass is also correlated with waist circumference. We therefore conducted this cross-sectional study to clarify the relationship between directly measured sizes of visceral and subcutaneous fat and microalbuminuria in patients with type 2 diabetes (T2DM). We studied a total of 208 adult Japanese individuals with T2DM, 99 women and 109 men, with a mean +/- A standard deviation (SD) age of 56 +/- A 13 years. Patients with macroalbuminuria, defined as a urinary albumin-to-creatinine ratio (ACR) a parts per thousand yen300 mg/g creatinine, and those with an estimated glomerular filtration rate < 15 ml/min/1.73 m(2) were excluded. Visceral and subcutaneous fat areas were measured by abdominal computed tomography. In the univariate correlational analysis, logarithmically transformed urinary ACR was significantly associated with visceral fat area (r = 0.14, p = 0.047) but not with subcutaneous fat area (r = 0.08, p = 0.237). In the multiple regression analysis with stepwise selection procedure, visceral fat area but not subcutaneous fat area was selected as an independent variable that was statistically associated with urinary ACR. This cross-sectional study suggests that increased visceral but not subcutaneous fat is independently associated with microalbuminuria in Japanese adult patients with T2DM.