Exercise in Adolescents Improves Risk of Osteoporosis Later in Life

A study published in JAMA Network Open found that high-intensity physical activity early in life may prevent osteoporosis later in life.

The prospective birth cohort Avon Longitudinal Study of Parents and Children study initially recruited pregnant women residing in southwest England who had an expected delivery date between April 1, 1991, and December 31, 1992.

A total of 15,454 eligible pregnant women were enrolled, and 15,589 infants were delivered, 14,901 of which were alive at one year. The current analysis examined 2,569 healthy offspring (1,588 female participants; 62%) who had valid physical activity measurements obtained during a clinical assessment for at least one age (12, 14, 16, and/or 25 years), with up to four repeated accelerometer assessments performed.

Male participants more often experienced moderate- to vigorous-intensity activity at each age and had greater adult femur neck bone mineral density (BMD) than female participants.

Three moderate- to vigorous-intensity trajectory subgroups and three light-intensity trajectory subgroups were identified for both men and women. With regard to the moderate- to vigorous-intensity trajectories, most male participants (85%) were in the low adolescent subgroup, with 6% and 9% in the high early-adolescent and high mid-adolescent subgroups, respectively. Moderate- to vigorous-intensity trajectories in female participants were divided into low adolescent-low adult (73%), low adolescent-high adult (8%), and high adolescent (19%) subgroups.

Femur neck BMD in male participants was greater in the high early-adolescent subgroup (0.38 g/cm2; 95% confidence interval [CI], 0.11-0.66) and the high mid-adolescent subgroup (0.33 g/cm2; 95% CI, 0.07-0.60) compared with the low adolescent (reference) subgroup.

Femur neck BMD in female participants was greater in the high adolescent subgroup (0.28 g/cm2; 95% CI, 0.15-0.41) but not in the low adolescent-high adult subgroup (−0.12 g/cm2; 95% CI, −0.44 to 0.20) compared with the low adolescent-low adult (reference) subgroup.

Light-intensity trajectories were not associated with femur neck BMD. Differences in femur neck BMD between the high decreasing and low non-linear subgroups were 0.16 g/cm2 (95% CI, −0.08 to 0.40) in male participants and 0.20 g/cm2 (95% CI, −0.05 to 0.44) in female participants.

“Supporting high-intensity physical activity throughout early life may help to maximize peak hip strength and prevent osteoporosis in later life,” the researchers concluded.