Is there a relationship between exercise systolic blood pressure response and left ventricular mass? The Framingham Heart Study

Abstract

Objective: To assess the association between an exaggerated exercise systolic blood pressure response and the occurrence of left ventricular hypertrophy in healthy, normotensive individuals.

Design: Cross-sectional survey using M-mode echocardiography to measure left ventricular mass and to detect left ventricular hypertrophy.

Setting: The Framingham Heart Study.

Subjects: Eight-hundred sixty men and 1118 women were studied who were free of cardiovascular or pulmonary disease, who were not taking any antihypertensive or cardiovascular medications, and who successfully achieved at least 90% of their age-predicted maximum heart rate during a monitored exercise treadmill test. All subjects had normal baseline and exercise electrocardiograms.

Measurements and main results: Men with a peak exercise systolic blood pressure of 210 or more and women with a peak exercise systolic blood pressure of 190 or more were considered to have an "exaggerated" blood pressure response; 122 men and 67 women met these criteria. Subjects with an exaggerated exercise systolic blood pressure response had 10% higher left ventricular mass than those with a normal exercise systolic blood pressure response (in men: 115 +/- 25 compared with 105 +/- 24 g/m, P less than 0.001; in women: 86 +/- 22 compared with 73 +/- 16 g/m, P less than 0.001); they also had a higher prevalence of left ventricular hypertrophy (in men: odds ratio, 1.34, 95% CI, 1.00 to 1.80; in women: odds ratio, 2.12, CI, 1.48 to 3.03). After adjusting for age, resting systolic blood pressure, and body mass index, however, subjects with an exaggerated exercise systolic blood pressure response had only 5% higher left ventricular mass (in men: 111 +/- 2.1 compared with 106 +/- 0.8 g/m, P = 0.02; in women: 80 +/- 1.8 compared with 74 +/- 0.4 g/m, P = 0.002), and they no longer had a statistically increased prevalence of left ventricular hypertrophy (in men: odds ratio, 1.21, CI, 0.87 to 1.67; in women: odds ratio, 1.30, CI, 0.84 to 2.01).

Conclusions: The apparent relation between exercise systolic blood pressure response and left ventricular mass is confounded by age, resting systolic blood pressure, and body mass; the degree of confounding is such that the biologic significance of this relationship should be questioned.