INCREASED URINARY ALBUMIN EXCRETION AGGREGATES WITH ATHEROSCLEROTIC RISK-FACTORS IN TYPE-2 (NON-INSULIN-DEPENDENT) DIABETES-MELLITUS

Supranormal urinary albumin excretion (microalbuminuria) is an early i ndicator of microangiopathy, i.e. diabetic nephropathy, and is associa ted with higher cardiovascular mortality in both type 1 and type 2 dia betes. The relationship between the presence of microalbuminuria and s ome atherosclerotic risk factors has been evaluated in 318 (170 male, 148 female) type 2 (non-insulin-dependent) diabetic subjects [age 63 /- 10 years; known duration of diabetes 10.9 +/- 8.8 years; age at dia betes diagnosis 52 +/- 11 years; systolic blood pressure (BP) 150 +/- 23 mmHg; diastolic BP 86 +/- 11 mmHg (mean +/-SD)]. In ''early morning '' urine samples, albumin (immunonephelometry) and creatinine were ass ayed. On the basis of the albumin/creatinine ratio (A/C, mg/mmol), pat ients were categorized as normoalbuminuric (Na; A/C < 2.0; n = 159, 50 %), microalbuminuric (ma; A/C 2-20; n = 135, 42.5%) or macroalbuminuri c (Ma; A/C > 20; n = 24, 7.5%). The three groups were closely matched for age, age at diagnosis, duration of diabetes, and fasting plasma an d urinary glucose levels. Systolic and diastolic BP rose progressively with increasing urinary A/C ratio levels. While high-density lipoprot ein (HDL) cholesterol was unaffected by albuminuria, total cholesterol (218 +/- 45 vs 198 +/- 43 mg/dl, P < 0.001) and low-density lipoprote in (LDL) cholesterol (145 +/- 42 vs 131 +/- 38 mg/dl, P < 0.05) levels were higher in microalbuminuric than in normoalbuminuric patients. Fu rther, a significant correlation (r = 0.16, P < 0.01) existed between albuminuria and triglyceride concentrations. Prevalence of arterial hy pertension, defined as BP greater-than-or-equal-to 160/95 mmHg and/or drug treatment (Na, 51%; ma, 65%, Ma, 78%; P < 0.001) and obesity, def ined as body mass index (BMI) > 30 (Na, 15%; ma, 26%; Ma, 32%; P < 0.0 5) rose with increasing A/C ratios. Both coronary heart disease (30% v s 15%) and intermittent claudication (18% vs 7%) were more frequent in microalbuminuric than in normoalbuminuric subjects. Finally, multiple stepwise regression analysis showed that urinary albumin excretion is significantly and independently associated with coronary heart diseas e and intermittent claudication, also taking into account hypertension and other established cardiovascular risk factors. In type 2 diabetes microalbuminuria tends to aggregate with risk factors for atheroscler otic vascular disease, e.g. increased prevalence of hypertension and o besity, elevated total and LDL cholesterol, and raised triglycerides l evels. These abnormalities may only explain the excess of cardiovascul ar morbidity and mortality in part. Microalbuminuria per se may be an important and independent cardiovascular risk factor.