Impaired left ventricular systolic function during exercise in middle-aged insulin-dependent and noninsulin-dependent diabetic subjects without clinically evident cardiovascular disease

Abstract

Equilibrium radionuclide angiocardiography was performed on 19 men and 17 women with insulindependent diabetes mellitus (IDDM) and on 24 men and 15 women with noninsulin-dependent diabetes mellitus (NIDDM) and on 24 male and 24 female control subjects aged 46 to 67 years. All were without clinically evident cardiovascular disease. No significant differences were found in left ventricular (LV) ejection fraction at rest between men with IDDM (56 ± 1%; mean ± standard error of the mean) or NIDDM (58 ± 1%) and control men (58 ± 1%), whereas LV ejection fraction was higher in women with IDDM (63 ± 1%; p < 0.01) and NIDDM (64 ± 2%; p < 0.01) than in control women (58 ± 1%). An abnormal LV ejection fraction response to dynamic exercise (an increase of <5% units or a decrease) was observed in 1 control man (4%), in 8 men with IDDM (42%, p < 0.01) and in 10 men with NIDDM (42%, p < 0.01). The respective figures were 4 (17%) for control women, 7 (44%, difference not significant) for women with IDDM and 10 (71%, p < 0.01) for women with NIDDM. Abnormal LV ejection fraction response to exercise in diabetic patients was not related to the metabolic control of diabetes, presence of microangiopathy or abnormalities in the autonomic nervous function. Myocardial perfusion scintigraphy performed in 18 diabetic patients in whom LV ejection fraction decreased during exercise showed a reversible perfusion defect in only 5 (28%). These results indicate that LV dysfunction on exercise may occur in both types of diabetic patients without any evidence of myocardial ischemia.