Cumulative associations between midlife health behaviors and physical functioning in early old age: A 17-year prospective cohort study

Abstract

Objectives To examine cumulative associations between midlife health behaviors and walking speed and upper-limb strength in early old age. Setting Whitehall II Study. Design Prospective cohort study. Participants Individuals (mean age 49.1 ± 5.9 in 1991-93) with health behavior data for at least two of the three assessments (1991-93, 1997-99, 2002-04) and physical functioning measures in 2007-09 (mean age 65.9 ± 5.9) (N = 5,671). Measurements A trained nurse assessed walking speed and upper-limb strength. Unhealthy behaviors were defined as current or recent smoking, nonmoderate alcohol consumption (abstinence or heavy drinking), fruit and vegetable consumption less than twice per day, and physical inactivity (<1 h/wk of moderate and <1 h/wk of vigorous physical activity). For each unhealthy behavior, a cumulative score was calculated as the number of times a person reported the behavior over the three assessments divided by 3. The score ranged between 0 (never) and 1 (all three times). Conclusion These findings highlight the importance of duration of unhealthy behaviors, particularly for diet and physical activity, when examining associations with physical functioning. Results In linear regression models adjusted for age, sex, education, marital status, and height, all unhealthy behaviors in 1991-93 were associated with slower walking speed in 2007-09, with differences ranging from 0.10 (nonmoderate alcohol consumption) to 0.25 (physical inactivity) of a standard deviation between participants with and without the unhealthy behavior (Pt-test