Determination of left ventricular mass by echocardiography in a normal population: effect of age and sex in addition to body size.

OBJECTIVE

In this study, we determined the effect of age, sex, and body size on left ventricular mass.

DESIGN

Two-dimensional-guided M-mode echocardiography was used in an assessment of 111 healthy, normal adults.

MATERIAL AND METHODS

Left ventricular mass was calculated with the cube function formula corrected by a regression equation to agree with autopsy estimates of left ventricular mass. Calculated left ventricular mass, indexed by body surface area and by height, was analyzed on the basis of sex and age of the study participants. Age was analyzed as a dichotomous, trichotomous, and continuous variable. The effects of age, sex, and obesity, as well as interactions, were tested within a multiple linear regression model framework.

RESULTS

Left ventricular mass, when indexed for either body surface area or height, was greater in men than in women. For women, but not men, we found a small but significant increase in left ventricular mass with advancing age. Body mass index, an indicator of obesity, increased with aging in women but not in men and affected left ventricular mass. No significant changes were noted in left ventricular cavity size with advancing age, and the increase in left ventricular mass in women was due to increased ventricular wall thickness.

CONCLUSION

The findings in this study suggest that left ventricular mass, as assessed by two-dimensional-guided M-mode echocardiography, is affected not only by sex and body size but also by age in women. This phenomenon may be related to an increase in body mass index with advancing age in women. In clinical studies that use echocardiographic left ventricular mass to diagnose left ventricular hypertrophy, these observations should be considered.