Urinary albumin and insulin as predictors of coronary artery disease: An angiographic study

Microalbuminuria has been associated with cardiovascular risk factors, even ts, and mortality. It also clusters with hyperinsulinemia and the metabolic syndrome. How urinary albumin excretion and the fasting serum insulin leve l relate to coronary artery disease (CAD) has not been previously determine d, In 308 patients undergoing elective coronary angiography, the albumin to creatinine ratio was measured in urine from an early morning void. The fas ting serum insulin level was also determined. CAD was assessed by angiograp hy, Urinary albumin excretion was 28 +/- 5 mg/g (mean +/- SE) in patients w ith CAD and 10 +/- 1 mg/g in those without CAD (P < 0.001). Fasting serum i nsulin levels were also greater in patients with CAD compared with those wi thout CAD; 20 +/- 3 and 13 +/- 1 mu U/mL, respectively (P = 0.016). Urinary albumin excretion and fasting serum insulin levels increased progressively with severity of CAD. In patients without diabetes (n = 255), significant relationships of urinary albumin excretion and the fasting serum insulin le vels to CAD were observed, but they were more pronounced when patients with diabetes (n = 53) were included. In multiple regression analysis, the odds ratios for severe CAD were 2.2 (95% confidence interval, 1.1 to 4.5) for m icroalbuminuria and 2.2 (95% confidence interval, 1.3 to 3.8) for hyperinsu linemia. In summary, urinary albumin excretion and the fasting serum insuli n levels were directly related to angiographic evidence of CAD. Microalbumi nuria and hyperinsulinemia predict a significantly elevated risk for corona ry atherosclerosis. (C) 1999 by the National Kidney Foundation, Inc.