The importance of age and obesity on the relation between diabetes and left ventricular mass

The study investigated the relation of age with diabetes, obesity and hypertension on left ventricular mass (LVM).

Epidemiological studies demonstrate a general rise of LVM with aging, but whether this phenomenon is independent or a function of coexisting diseases that accompany the aging process is unclear. Although obesity, hypertension and diabetes often coexist and increase in prevalence with age, studies of LVM in diabetics have been reported in mostly nonobese populations, and with little regard to the age-hypertension-obesity interactions and effects on LVM.

We prospectively measured LVM in 875 consecutive, mostly obese individuals (673 men, 202 women). Clinical data were obtained by chart review and clinical history. Echocardiographic measurements of LVM (American Society of Echocardiography criteria) were calculated using the Devereux formula and corrected for height2.7 (LVM/Ht).

Mean age was 49.3+/-12.3 years, body mass index 33.3+/-8.0 kg/m2, and LVM/Ht2.7 41.7+/-13.4 g/m2.7. Of the total cohort, 673 patients were men, 519 obese, 228 hypertensive, and 52 diabetic. Of the 519 obese, 183 were hypertensive and 44 were diabetic (22 of those were hypertensive). Of the 228 hypertensives, 183 were obese and 26 were diabetic. On multivariate analysis, obesity (p = 0.0001), age (p = 0.0001), hypertension (p = 0.0003) and diabetes (p = 0.62) were all independently associated with LVM/Ht2.7. Obesity was the most potent independent predictor of LVM/Ht2.7, associated with an increase of 8.1 g/m2.7 in LVM/Ht2.7. In diabetics, obesity had a synergistic effect on LVM/Ht2.7 (p = 0.006), which was further amplified by age (p = 0.03).

Age, obesity, hypertension and diabetes are all independent determinants of LVM. The magnitude of the effect of diabetes on LVM is mainly consequent to a significant interaction of diabetes with obesity and age.