Lifelong physical activity in maintaining bone strength in older men and women of the Age, Gene/Environment Susceptibility-Reykjavik Study

Abstract

We examined if lifelong physical activity is important for maintaining bone strength in the elderly. Associations of quantitative computerized tomography-acquired bone measures (vertebral and femoral) and self-reported physical activity in mid-life (mean age, 50 years), in old age (≥65 years), and throughout life (recalled during old age) were investigated in 2,110 men and 2,682 women in the AGES-Reykjavik Study. Results conclude lifelong physical activity with continuation into old age (≥65 years) best maintains better bone health later in life.

Introduction: Skeletal loading is thought to modulate the loss of bone in later life, and physical activity is a chief means of affecting bone strength by skeletal loading. Despite much discussion regarding lifelong versus early adulthood physical activity for preventing bone loss later in life, inconsistency still exists regarding how to maintain bone mass later in life (≥65 years).

Methods: We examined if lifelong physical activity is important for maintaining bone strength in the elderly.

Results: The associations of quantitative computerized tomography-acquired vertebral and femoral bone measures and self-reported physical activity in mid-life (mean age, 50 years), in old age (≥65 years), and throughout life (recalled during old age) were investigated in 2,110 men and 2,682 women in the AGES-Reykjavik Study.

Conclusion: Our findings conclude that lifelong physical activity with continuation into old age (≥65 years) best maintains better bone health in the elderly.

Fig. 1

Associations between PA from different stages of life as reported at older age (≥65 years) and QCT bone measures—results from backward stepwise regression models for men and women. Notes: (1) Fig. 1 reports results from backward stepwise multiple regression models—four models for women on the left and four models for men on the right of the figure. In the eight regression models, the QCT bone variables (VBMD vertebral BMD, NCSA femoral neck minimum cross-sectional area, CorTh femoral neck cortical thickness, FNTB femur neck trabecular BMD) were the outcome variables (one model for each variable), and the PA variables from four stages (current life, ≥65 years; late middle, 50–64 years; early middle, 35–49 years; young adulthood, 20–34 years) of life were the independent variables. β with 95%CI for the last remaining variable from each model is represented in the figure. Current life PA remained as the last variable in all of the models except in the model with FNTB* for men where early middle age PA remained as the last variable. (2) The control variable for each model was men and women who reported <4 h/week PA for that particular stage of life. Models were adjusted for age, height at age 25 years, weight, education, smoking, alcohol use, self-reported health status, bone-promoting medication use, ADL, leg muscle strength, and walking speed