PREDICTORS OF MICROALBUMINURIA IN INDIVIDUALS WITH IDDM

OBJECTIVE- To examine the relationships between microalbuminuria and t he development of overt diabetic nephrology, elevated blood pressure, and a more atherogenic lipid profile; and to identify risk factors for the development of microalbuminuria in individuals with IDDM. Microal buminuria has been associated with the subsequent development of overt diabetic nephropathy in individuals with IDDM. it is associated with elevated blood pressure and a more atherogenic lipid profile, but the temporal relationship between the development of microalbuminuria and the changes in these factors is unclear. RESEARCH DESIGN AND METHODS - Baseline characteristics were examined in 256 individuals with IDDM w ho had normal albumin excretion (urinary AER less-than-or-equal-to 20 mug/min in greater-than-or-equal-to 2 timed urine collections) and wer e re-examined 2 yr later. RESULTS- At follow-up, 24 had developed micr oalbuminuria (AER 20-200 mug/min in greater-than-or-equal-to 2 timed u rine collections) and 1 had developed overt nephropathy (AER > 2 00 mu g/min). Overall, the significant independent predictors of microalbumi nuria were HbA1 (P < 0.001), low-density lipoprotein (P < 0.01), durat ion of IDDM (P < 0.05), and systolic blood pressure (P = 0.05). Sex-sp ecific analyses showed HbA1, age, and baseline AER were particularly i mportant for men; whereas, for women, the main predictors were duratio n of IDDM and triglycerides. Duration-specific analyses showed that Hb A, was an important predictor both for individuals with < and > 20-yr duration. Low-density lipoprotein cholesterol was more important for s ubjects with shorter durations; whereas triglycerides were important f or those with longer durations. CONCLUSIONS- These results suggest tha t glycemic control, age or duration of IDDM, disturbed lipids, and pos sibly elevated blood pressure all may contribute to the development of microalbuminuria; and, further, that the adverse cardiovascular risk profile seen in individuals with overt nephropathy may begin to develo p even before the detection of microalbuminuria.