EFFECT OF RISK-FACTORS ON EXERCISE CAPACITY IN NIDDM

Exercise capacity has been used as a noninvasive parameter for predict ing 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 NID DM patients who underwent graded exercise testing with expired gas ana lysis were studied to determine the possible influences of demographic and cardiac risk factors on exercise capacity. Univariate and multipl e Linear regression analyses were performed on baseline patient charac teristics with respect to peak oxygen consumption (VO2). In the regres sion analyses, African-American race was strongly associated with a de crease 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, -0.0 7, 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-A merican subjects had increased prevalence, longer duration, and higher systolic and diastolic hypertension than the non-Hispanic and Hispani c whites. Other independent predictors of peak VO2 (reported as change in peak VO, in milliliters per kilogram per minute) were BMI (men: -0 .39 kg/m(2) [-0.52, -0.29],P < 0.0001; women: -0.39 kg/m(2) [-0.48, -0 .31], P < 0.0001), age (men: -0.16/year [-0.23, -0.09], P < 0.0001; wo men: -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: -0.0 3/mmHg [-0.06, -0.01],P < 0.05), and pack-years smoking (men: -0.04/pa ck-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, smokin g cessation, and aggressive blood pressure control, particularly in Af rican-Americans with NIDDM, would appear to be important in improving exercise capacity and potentially improving the increased cardiovascul ar mortality associated with an impaired exercise capacity.