Prospective study of heart disease in untreated maturity onset diabetics.

Abstract

Frequent abnormalities of left ventricular function were demonstrated by systolic time intervals and M-mode echocardiography in 69 maturity onset diabetics without clinical heart disease before and during standard hypoglycemic treatment. The response of the ratio of pre-ejection period (PEP) to left ventricular ejection time (LVET) during the first 2 mo. of treatment identified 2 groups of patients. Group A had a normal or slightly raised ratio which fell with treatment. In group B the ratio was significantly higher and did not change even after 4 mo. treatment. The change in group A apparently was due to the improvement in blood glucose, as the correlation between the random blood glucose before treatment and PEP/LVET ratio was lost with reduction of hyperglycemia. The persistently raised PEP/LVET in group B suggested significant left ventricular dysfunction. Abnormalities of the diastolic closure rate and isovolumic relaxation time were frequently detected and in 9 of 69 patients were within 2 SD from normal. They were more pronounced in group B and were significantly different from group A and normal subjects. Group B could be subdivided into 6 patients (group B1) with outward wall motion in isovolumic relaxation and delayed aortic valve closure caused by incoordination and 9 (group B2) who did not show these changes. An exercise ECG was positive in 2 of 5 group B1 patients and negative in the 7 tested in group B2. Three patients in group B2 and 1 in group A had clinically apparent diabetic microvascular disease. Coronary artery disease was common and 7 patients (6 in group B1 and 1 in group A) demonstrated left ventricular wall dyskinesis in the absence of symptoms; 11 of the original group of 110 were excluded because of symptomatic disease. A smaller group had slow ejection and relaxation, probably due to increased left ventricular stiffness from myocardial involvement by diabetic microvascular disease.