Importance of overweight in studies of left ventricular hypertrophy and diastolic function in mild systemic hypertension

Abstract

The relations of Metropolitan Life Insurance Co. Relative Weight values and blood pressure (BP) to minimal forearm vascular resistance, ventricular septal and posterior wall thickness, left ventricular (LV) mass index and cardiac diastolic function were assessed in 31 men, 37 ± 2 (mean ±standard error of the mean) years of age. Eighteen patients with untreated mild hypertension were compared with 13 normotensive control subjects of similar age and weight. The hypertensives had higher clinic (137 ± 3 96 ± 2 vs 121 ± 4 81 ± 3 mm Hg, p < 0.001 < 0.001 ) and home (p < 0.001) BP. Despite higher BP, the hypertensives did not have significantly greater values than normotensives, respectively, for minimal forearm vascular resistance (2.20 ± 0.12 vs 2.04 ± 0.11 U), ventricular septal (9.9 ± 0.5 vs 10.2 ± 0.3 mm) and posterior wall thickness (10.2 ± 0.4 vs 10.0 ± 0.3 mm) or LV mass index (106 ± 6 vs 107 ± 6 g/m 2). Furthermore, diastolic peak filling rate, an index of LV diastolic function, was virtually identical in the 2 groups (2.71 ± 0.14 vs 2.69 ± 0.07 liters/s, difference not significant). Correlates of peak filling rate included relative weight (r = −0.62, p < 0.001), posterior wall thickness (r = −0.51, p < 0.01) and age (r = −0.45, p < 0.05). Relative weight also correlated significantly with posterior wall (r = 0.59, p < 0.005), ventricular septal (r = 0.47, p < 0.005) and LV mass index (r = 0.38, p < 0.05). Although dink systolic BP correlated directly with posterior wall thickness (r = 0.45, p < 0.05), neither systolic nor diastolic BP in the clinic or at home correlated significantly with peak filling rate (r = −0.26 to +0.02, difference not significant). The results suggest that relative weight is an important determinant of diastolic function and LV dimensions. These findings highlight the importance of controlling for weight in comparative studies of cardiovascular structure and function.