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Objective: Exercise capacity has been used as a noninvasive parameter for predicting cardiovascular events. It has been demonstrated previously in NIDDM patients that several risk factors (i.e., obesity, smoking, hypertension, and African-American race) are associated with an impaired exercise capacity. We studied 265 male and 154 female NIDDM patients who underwent graded exercise testing with expired gas analyses to determine the possible influences of diabetic neuropathy, nephropathy, and retinopathy on exercise capacity., Research Design and Methods: Univariate and multiple linear regression analyses were performed to determine the relationship between diabetic neuropathy, urinary albumin excretion (UAE), and retinopathy with respect to peak oxygen consumption (VO2). Neuropathy was assessed by neurological symptom and disability scores, autonomic function testing, and quantitative sensory exams involving thermal and vibratory sensation. Three categories of UAE were used: normal albuminuria (< 20 micrograms/min), microalbuminuria (20-200 micrograms/min), and overt albuminuria (> 200 micrograms/min). Retinopathy was assessed by stereoscopic fundus photographs. Multiple linear regression analyses were then performed controlling for age, sex, length of diagnosed diabetes, duration of hypertension, race and ethnicity, GHb, BMI, and smoking to determine whether there was an independent effect of these diabetic complications on exercise capacity., Results: Univariate analyses revealed that the presence of diabetic retinopathy (P = 0.03), neuropathy (P = 0.002), microalbuminuria (P = 0.04), and overt albuminuria (P = 0.06) were associated with a lower peak VO2. Multiple linear regression analyses were performed to determine independent relationships with peak VO2. The results revealed that increasing retinopathy stage (Parameter estimate [PE] = -0.59 +/- 0.3 ml.kg-1.min-1; P = 0.026) and increasing UAE stage (PE = -0.62 +/- 0.3 ml.kg-1.min-1; P = 0.04) were associated with a decrease in peak VO2., Conclusions: In the present study of NIDDM subjects, a significant independent association was demonstrated between diabetic nephropathy and retinopathy with exercise capacity. These results were obtained controlling for age, sex, length of diagnosed diabetes, hypertension, race, and BMI. Thus the findings in this large NIDDM population without a history of coronary artery disease indicate a potential pathogenic relationship between microvascular disease and exercise capacity.

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.

Exercise capacity has been used as a noninvasive parameter for predicting cardiovascular events. It is known that diabetic patients have an impaired exercise capacity when compared with nondiabetic age-matched control subjects, but the risk factors associated with this impairment have not been thoroughly analyzed. A total of 453 male and female NIDDM patients who underwent graded exercise testing with expired gas analysis were studied to determine the possible influences of demographic and cardiac risk factors on exercise capacity. Univariate and multiple linear regression analyses were performed on baseline patient characteristics with respect to peak oxygen consumption (VO2). In the regression analyses, African-American race was strongly associated with a decrease in peak VO2; the difference in means between African-Americans and other subjects for men was -2.50 ml.kg-1.min-1 (-4.28, -0.07, 95% CI) (P < 0.006) and for women was -2.96 ml.kg-1.min-1 (-4.45, -1.47) (P < 0.0002). Univariate analyses revealed that African-American subjects had increased prevalence, longer duration, and higher systolic and diastolic hypertension than the non-Hispanic and Hispanic whites. Other independent predictors of peak VO2 (reported as change in peak VO2 in milliliters per kilogram per minute) were BMI (men: -0.39 kg/m2 [-0.52, -0.29], P < 0.0001; women: -0.39 kg/m2 [-0.48, -0.31], P < 0.0001), age (men: -0.16/year [-0.23, -0.09], P < 0.0001; women: -0.17/year [-0.24, -0.11], P < 0.0001), baseline resting systolic blood pressure (men: -0.03/mmHg [-0.06, -0.01], P < 0.05; women: -0.03/mmHg (-0.06, -0.01)f1p4< 0.05), and pack-years smoking (men: -0.04/pack-years [-0.04, -0.01], P < 0.01; women: -0.04/pack-years [-0.07, -0.01], P < 0.0001). Thus, in this large NIDDM study, weight loss, smoking cessation, and aggressive blood pressure control, particularly in African-Americans with NIDDM, would appear to be important in improving exercise capacity and potentially improving the increased cardiovascular mortality associated with an impaired exercise capacity.