RISK-FACTORS FOR NEPHROPATHY AND CARDIOVASCULAR-DISEASE IN DIABETIC NORTHERN MINNESOTA AMERICAN-INDIANS

Although complications of diabetes are common among Southwest American Indians, little is known about diabetes and associated risk factors f or nephropathy and cardiovascular disease in other genetically distinc t tribes. We conducted a retrospective analysis of 665 diabetic patien ts at two Chippewa Indian reservations in northern Minnesota to evalua te the prevalence of risk factors for diabetic nephropathy, and cardio vascular disease. In 79 patients, a more detailed study was carried ou t, including an assessment of renal function and urinary albumin excre tion (UAE). The overall prevalences of proteinuria and hypertension we re 47.9% and 62.6%, respectively. Proteinuria was observed more often in hypertensive than in non-hypertensive patients (55.2% us 44.4%, p < 0.05), and in patients with diabetes for longer than 10 years (57% vs 40% for diabetes less than 10 years, p < 0.05). Although hypercholest erolemia (total cholesterol greater than or equal to 200 mg/dl) was ob served in 54% of patients, there was no relationship between hyperchol esterolemia and proteinuria. In the 79 patients studied in more detail , UAE was greater in hypertensive patients compared to non-hypertensiv e patients (606 +/- 1560 mg/24 h vs 101 +/- 157 mg/24 h, p < 0.05), an d in patients with diabetes for 10 years or longer compared to patient s in the first decade of disease (748 +/- 1732 mg/24 h vs 96 +/- 171 m g/24 h, p < 0.05). Hypercholesterolemia and elevated LDL-cholesterol ( > 130 mg/dl) were observed in 56% and 49% of patients, respectively, b ut were not associated with increased UAE. In contrast, hypertriglycer idemia (> 250 mg/dl) was associated with an elevated UAE (932 +/- 2150 mg/24 h us 245 +/- 735 mg/24 h, p < 0.05). Increased lipoprotein(a) w as found in patients with overt albuminuria. In summary, the prevalenc e of risk factors for diabetic nephropathy and associated cardiovascul ar disease is high in Chippewa American Indians in northern Minnesota. Although detecting abnormal UAE may be useful in identifying high-ris k patients who may benefit from early intervention, traditional risk f actors such as hypercholesterolemia may not explain the risk associate d with increased UAE.