Microalbuminuria is associated with the insulin resistance syndrome independent of hypertension and type 2 diabetes in the Korean population

To investigate whether microalbuminuria in is associated with the insulin r esistance syndrome independent of hypertension and type 2 diabetes, we stud ied the association between microalbuminuria and features of insulin resist ance syndrome in Korean general population. We selected 1006 subjects by a random cluster sampling among residents: aged > 40 years living in the Chun g-Up district, a rural area of South Korea. Subjects were stratified by ora l glucose tolerance status [normal glucose tolerance (NGT), impaired glucos e tolerance (IGT), and diabetes mellitus], and by the presence or absence o f hypertension. Urinary albumin excretion rate (UAER) was determined using timed overnight urine collection. Various cardiovascular risk factors inclu ding anthropometric indices, serum lipid, true insulin and proinsulin conce ntrations were also measured. The prevalence of microalbuminuria (UAER betw een 20 and 200 mug/min) increased as the glucose tolerance worsened (6.0% i n NGT, 11.8% in IGT, and 21.8% in diabetes; x(2) trend = 25.9, P < 0.001). Subjects with microalbuminuria had a higher body mass index (BMI), waist-to -hip circumference ratio (WHR). systolic and diastolic blood pressure (BP), fasting and 2 h plasma glucose, fasting plasma insulin and proinsulin leve ls, and lower HDL-cholestrol level than subjects without microalbuminuria. In multiple regression analysis, BMI diastolic BP, 2 h plasma glucose, and fasting plasma insulin levels were found to be independent factors associat ed with UAER. Multiple logistic regression analysis showed that not only di abetes mellitus and hypertension, but also Fasting hyperinsulinemia and wai st-to-hip ratio were independent factors associated with the presence of mi croalbuminuria. When the normotensive, non-diabetic subjects were analyzed separately, fasting hyperinsulinemia and impaired glucose tolerance remaine d independent variables associated with the presence of microalbuminuria. T hese results show that microalbuminuria in the Korean general population is associated with hyperinsulinemia and central obesity, and suggest that mic roalbuminuria is a feature of the insulin resistance syndrome independent o f hypertension or type 2 diabetes. (C) 2001 Elsevier Science Ireland Ltd. A ll rights reserved.