Increased left atrial size relative to left ventricular size in young women with insulin-dependent diabetes; a pre-clinical sign of the specific heart disease of diabetes?

Echocardiography was performed on 71 young (mean age 26 years) insulin-dependent diabetic women without clinical evidence of heart disease and on 36 healthy women of the same age. 39 diabetic women had microvascular complications and 9 of them also had abnormalities in autonomic function tests. The diabetic women had smaller left ventricular (LV) end-diastolic diameters (44 vs. 47 mm, p less than 0.001) than the controls, although the left atrial sizes did not differ between the groups. They also had higher heart rates (80 vs. 70 bpm, p less than 0.001) and shortening fractions (35 vs. 33%, p less than 0.01), smaller stroke volumes (66 vs. 76 ml, p less than 0.01) and thicker interventricular septae (9 vs. 8 mm, p less than 0.01) than the controls. The diminution of LV size was most prominent in patients with severe microvascular complications. These data suggest that the myocardial contractility of young insulin-dependent diabetic women is not depressed, but rather exaggerated. The observed diminution of LV size in combination with normal left atrial diameter may reflect increased LV wall stiffness, a possible pre-clinical manifestation of the specific heart disease of diabetes.