Our laboratory utilizes multiple techniques to determine the effects of age, gender and lifestyle habits on cardiovascular (CV) performance at rest and during exercise. (A) We examined whether age affects midwall systolic left ventricular (LV) performance, a more sensitive marker for determining myocardial dysfunction than standard endocardial measures. In 330 normal BLSA men (n=141) and women (n=189), those older than the median age of 50 years had smaller LV cavities, greater wall thickness, and higher endocardial fractional shortening than younger subjects. However, midwall shortening was not significantly age-related in either sex. Furthermore, the relationship between midwall shortening and end-systolic stress was similar in older versus younger groups. Thus, normative aging appears to have minimal effect on LV systolic performance whether measured at the LV endocardium or the midwall. (B) Longitudinal changes of maximal aerobic capacity (VO2max) were determined in nearly 1,400 Baltimore Longitudinal Study of Aging (BLSA) volunteers without evident cardiac disease, using mixed effects statistical analysis. Per decade, longitudinal declines in VO2max were generally greater than cross-sectional declines, especially in older decades. Gender differences in both absolute VO2max and rates of decline (men>women) are markedly attenuated when VO2max was normalized for fat-free mass rather than body weight. (C) The longitudinal decline in VO2max was determined in 42 older male endurance athletes, initially 64 (plus or minus) 6 years old. Over a mean follow-up of 7.8 years, VO2max declined by 22%, triple the decrease predicted by the baseline cross-sectional data. Within the overall sample, training status during follow-up had a major effect on the change in VO2max: the 6 men who continued to train vigorously had no significant decline in VO2max (0.28%/yr.), the 20 that trained at a lower intensity declined by 2.6% / yr, and the 14 who stopped training declined 4.6% / yr. Thus, physical activity patterns have a major impact on the long-term changes in maximal aerobic capacity in older athletes.
