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Non-insulin-dependent diabetes mellitus (NIDDM) occurs with a higher frequency in Hispanic as compared with non-Hispanic whites. It also appears that there is a higher prevalence of diabetic nephropathy in the Hispanic population when compared with non-Hispanic whites. In the current study, 144 Hispanics and 671 non-Hispanic white NIDDM subjects were studied to determine the possible association of various risk factors and diabetic complications, including overt albuminuria, with diabetic retinopathy. Stereoscopic retinal fundus photographs were obtained and graded by the University of Wisconsin Fundus Photographic Reading Center. We also sought to determine whether risk factors for retinopathy vary between Hispanics and non-Hispanic whites. In the total group, duration of diabetes, glycosylated hemoglobin, neuropathy, diastolic hypertension, use of insulin, and Hispanic ethnicity correlated with the presence of retinopathy. Controlling for severity and duration of diabetes, Hispanics had a significantly increased risk of retinopathy relative to non-Hispanic whites (OR = 2.13, 95% CI = 1.34, 3.37, P = 0.0013). Duration of diabetes and presence of neuropathy were significantly correlated with the presence of diabetic retinopathy in Hispanics and non-Hispanic whites. The presence of overt albuminuria (>200 microg/min), although not related to diabetic retinopathy in non-Hispanic whites, conferred a high risk for diabetic retinopathy in Hispanics (OR = 11.14, CI = 1.20, 103.39, P = 0.0339) independent of other risk factors. In summary, Hispanics with NIDDM have an increased prevalence of diabetic retinopathy when compared with non-Hispanic whites. In addition, overt albuminuria in the Hispanic subjects appears to be a powerful predictor of the diabetic retinopathy.

The ABCD (Appropriate Blood Pressure Control in Diabetes) Trial is a large, prospective, randomized clinical trial of 950 patients with non-insulin-dependent diabetes mellitus (NIDDM) designed to compare the effects of intensive blood pressure control with moderate control on the prevention and progression of diabetic nephropathy, retinopathy, cardiovascular disease, and neuropathy in NIDDM. The secondary objective is to determine equivalency of the effects of a calcium channel blocker (nisoldipine) and an angiotensin-converting-enzyme inhibitor (enalapril) as a first-line antihypertensive agent in the prevention and/or progression of these diabetic vascular complications. The study consists of two study populations aged 40-74 years, 470 hypertensive patients (diastolic blood pressure of > or = 90.0 mmHg at time of randomization) and 480 normotensive patients (diastolic blood pressure of 80.0 mmHg at time of randomization). The study duration is 5 years and is scheduled to end in May of 1998. Patients are randomized to receive either intensive antihypertensive drug therapy or moderate antihypertensive drug therapy. Patients are also randomized to nisoldipine or enalapril, with open-label medications added if further blood pressure control is necessary. The primary outcome measure is glomerular filtration rate as assessed by 24-h creatinine clearance. Secondary outcome measures are urinary albumin excretion, left ventricular hypertrophy, retinopathy, and neuropathy. Cardiovascular morbidity and mortality will also be evaluated. Given the data showing the impact of hypertension on complications in NIDDM, the ABCD Trial is designed to determine if intensive antihypertensive therapy will be more efficacious than moderate antihypertensive therapy on the outcome of diabetic complications in NIDDM.

Objective: The relationship between urinary albumin excretion (UAE) and diabetic complications in NIDDM has not been studied in a large American population. The demonstrated relationship between increased UAE and the development of retinopathy, nephropathy, and neuropathy in IDDM makes this an important issue to also be studied in NIDDM patients., Research Design and Methods: A large population study of 947 NIDDM patients living predominantly in a metropolitan area was undertaken. Three categories of UAE, namely, normal albuminuria (< 20 micrograms/min), microalbuminuria (20-200 micrograms/min), and overt albuminuria (> 200 micrograms/min) were compared with 1) retinopathy as assessed by stereoscopic fundus photographs; 2) cardiovascular disease as assessed by a history of cardiac disease or stroke; ischemic changes on exercise treadmill testing; Q wave myocardial infarction; Estes, Sokolow, or Cornell criteria for left ventricular hypertrophy; positive Rose questionnaire for angina; and an abnormal Doppler exam for peripheral vascular disease; and 3) neuropathy as assessed by neurological symptom and disability scores, autonomic function testing, and quantitative sensory exams involving thermal and vibratory sensation. Selected patient characteristics were then evaluated to determine their effects on the presence of diabetic complications using univariate analyses. Multiple logistic regression analyses were then performed to determine the independent effect of UAE on these diabetic complications., Results: chi 2 analyses revealed that UAE was significantly associated with the presence of retinopathy (P < 0.001), neuropathy (P < 0.001), and cardiovascular disease (P < 0.001). In the multiple logistic regression analyses, UAE had strong independent associations with retinopathy, neuropathy, and cardiovascular disease., Conclusions: Thus, increasing UAE in this large NIDDM population in the U.S. was associated with an increased prevalence of diabetic retinopathy, neuropathy, and cardiovascular disease. This suggests that UAE may be more than an indicator of renal disease in NIDDM patients and, in fact, may reflect a state of generalized vascular damage occurring throughout the body. Prospective studies in NIDDM patients are needed to determine the predictive effect of UAE and the effect of decreasing UAE on future diabetic micro- and macrovascular complications.