Dexter L. Jung

The Association of Changes in Physical-Activity Level and Other Lifestyle Characteristics with Mortality among Men

BACKGROUND Recent trends toward increasing physical exercise, stopping cigarette smoking, and avoiding obesity may increase longevity. We analyzed changes in the lifestyles of Harvard College alumni and the associations of these changes with mortality. METHODS Men who were 45 to 84 years of age in 1977 and who had reported no life-threatening disease on questionnaires completed in 1962 or 1966 and again in 1977 were classified according to changes in lifestyle characteristics between the first and second questionnaires. We analyzed changes in their level of physical activity, cigarette smoking, blood pressure, and body weight, and the relation of these factors to mortality between 1977 and 1985. RESULTS Of the 10,269 men, 476 died during this period (which totaled 90,650 man-years of observation). Beginning moderately vigorous sports activity (at an intensity of 4.5 or more metabolic equivalents) was associated with a 23 percent lower risk of death (95 percent confidence interval, 4 to 42 percent; P = 0.015) than not taking up moderately vigorous sports. Quitting cigarette smoking was associated with a 41 percent lower risk (95 percent confidence interval, 20 to 57 percent; P = 0.001) than continuing smoking, but with a 23 percent higher risk than constant nonsmoking. Men with recently diagnosed hypertension had a lower risk of death than those with long-term hypertension (relative risk, 0.75; 95 percent confidence interval, 0.55 to 1.02; P = 0.057), as did men with consistently normal blood pressure (relative risk, 0.52; 95 percent confidence interval, 0.40 to 0.68; P < 0.001). Maintenance of lean body mass was associated with a lower mortality rate than long-term, recent, or previous obesity. The associations between changes in lifestyle and mortality were independent and were largely undiminished by age. Our findings on death from coronary heart disease mirrored those on death from all causes. CONCLUSIONS Beginning moderately vigorous sports activity, quitting cigarette smoking, maintaining normal blood pressure, and avoiding obesity were separately associated with lower rates of death from all causes and from coronary heart disease among middle-aged and older men.

Physical Activity and Hypertension: An Epidemiological View

We examined patterns of physical activity and other characteristics that might deter hypertension or delay all-cause mortality among university alumni, 1962-1985. Collegiate sports play did not alter hypertension incidence, nor did contemporary walking, stair-climbing, or light sports play among 5463 University of Pennsylvania alumni, 739 of whom developed hypertension. But vigorous sports play reduced hypertension incidence; and overweight, gain in weight, history of parental hypertension, or any combination of these, increased it. Among 819 hypertensive Pennsylvania alumni (138 died during follow-up), vigorous sports play had minimal influence on mortality; but freedom from overweight and cigarette smoking deferred death. Among 16,936 Harvard College alumni, of whom 2614 died during follow-up, lack of vigorous sports play, or presence of hypertension, cigarette smoking, and overweight increased risk of premature mortality, heightened by any combination of these adverse characteristics. Overall, we found an inverse relationship between vigorous sports participation and hypertension risk but a direct relationship between risk and weight-for-height, weight gain, or parental hypertension. With regard to all-cause mortality, cigarette smoking and hypertension were most hazardous for the individual; smoking and lack of vigorous recreational play were most hazardous for the alumnus population as a whole.

Reliability of recalled physical activity, cigarette smoking, and alcohol consumption

Reliability of recalled measures of physical activity and alcohol and tobacco use was examined in a cohort of 873 men and women in three California communities. In personal interviews in 1972, participants provided baseline data on these three habits. In repeat interviews in 1983, they recalled their habits in 1972 and reported their current habits. On average, recalled physical activity levels significantly exceeded those originally reported (1899 kcal/d versus 1345 kcal/d, P < 0.001) and were similar to current reported levels (1822 kcal/d). Similarly, recalled alcohol and cigarette consumption was higher than the original reports (alcohol: 126 versus 119 g/wk; cigarettes: 8.5 versus 6.2/d). By contrast, current reported alcohol (103 g/wk) and cigarette consumption (4.6/d) were lower than at baseline. Analysis of variance was used to partition the variation in recalled and original habits into components due to interpersonal variation in true measures, errors in recall, and residual reporting error. Interpersonal variation accounted for only 20% of the total variation in physical activity, but for 48 to 60% of total variation in cigarette smoking and alcohol consumption. These results suggest that inconsistencies among studies of chronic disease and physical activity may arise from either large random measurement errors in individual assessments or from homogeneity of activity levels among the populations studied.