LEFT-VENTRICULAR SYSTOLIC FUNCTION IN MIDDLE-AGED PATIENTS WITH DIABETES-MELLITUS

In cross-sectional studies of asymptomatic diabetic patients, multiple abnormalities in left ventricular (LV) function have been found. Long -term significance of these abnormalities is unknown because follow-up studies have not been previously performed. LV ejection fraction (EF) by radionuclide angiocardiography was examined in middle-aged control subjects (n = 44), in patients with insulin-dependent (IDDM) (n = 32) and non-insulin-dependent (NIDDM) (n = 32) diabetes mellitus at basel ine and after 4-year follow-up. At baseline, all study subjects were f ree from cardiovascular disease. LVEF at rest did not differ between t he groups at baseline. The decrease in LVEF at rest during follow-up w as 1.1 +/- 1.1% (mean +/- SEM) in control subjects, 3.1 +/- 1.3% (p = NS, compared with control subjects) in patients with IDDM, and 7.2 +/- 1.4% (p <0.01) in patients with NIDDM. At follow-up examination, abno rmally low LVEF at rest (<50%) was found in 7% of control subjects, 13 % of patients with IDDM (p = NS), and in 31% of patients with NIDDM (p <0.05). Compared with control subjects, the prevalence of an abnormal LVEF response to exercise (an increase by <5%, or a decrease) was hig her in diabetic groups at both examinations. This prevalence increased in control subjects from 10% at baseline to 26% at follow-up examinat ion. In patients with IDDM, the respective increase was from 43% to 52 % (p = NS, compared with control subjects), and in patients with NIDDM from 53% to 73% (p = NS). Duration and metabolic control of diabetes, presence of diabetic complications, and LVEF at rest or during exerci se at baseline did not differ in either diabetic group between the pat ients who had normal or abnormal LVEF at rest or in response to exerci se at follow-up examination. No study subject experienced clinical hea rt failure during follow-up, but 7% of control subjects, 37% of patien ts (p = 0.001) with IDDM and 34% of patients (p = <0.01) with NIDDM ha d coronary artery disease at follow-up examination. In conclusion, LVE F at rest deteriorated significantly during 4-year follow-up in patien ts with NIDDM but not in patients with IDDM. A high prevalence of subc linical LV systolic dysfunction became evident both in patients with I DDM and patients with NIDDM as an abnormal LVEF response to exercise b oth at baseline and follow-up examinations.