Sedentary behavior patterns and bone health among overweight/obesity older women: a cross-sectional study

Recent studies have indicated an association between sedentary behavior (SB), particularly patterns of SB, and bone health. However, it remains uncertain how different patterns of SB in overweight/obesity older women impact their bone health. This study aimed to investigate the association between objectively measured SB patterns and bone health in Chinese community-dwelling overweight/obesity older women.

Cross-sectional data were obtained from a baseline survey of Physical Activity and Health in Older Women Study. Quantitative ultrasound was used to measure speed of sound (SOS), broadband ultrasound attenuation (BUA), bone quality index (BQI) and T value to evaluate bone health. SB patterns were measured using triaxial accelerometers, including sedentary time in SB bouts of ≥ 10, 30, and 60 min, number of SB bouts ≥ 10, 30, and 60 min. Multiple linear regression was used to examine the associations of different SB patterns with bone health.

After adjusting for confounders, sedentary time in SB bouts ≥ 60 min, number of SB bouts ≥ 60 min were significantly associated with bone health, with a lower SOS [β = -2.75, 95% confidence interval (CI): -4.96 to -0.53, P = 0.015], BUA (β = -1.20, 95% CI: -2.14 to -0.26, P = 0.013), BQI (β = -1.56, 95% CI: -2.63 to -0.49, P = 0.004), T value (β = -0.08, 95% CI: -0.14 to -0.03, P = 0.004) per 60 min increase of sedentary time in SB bouts ≥ 60 min, and a lower SOS (β = -3.97, 95% CI: -7.54 to -0.40, P = 0.029), BUA (β = -1.80, 95% CI: -3.44 to -0.16, P = 0.031), BQI (β = -2.28, 95% CI: -4.08 to -0.47, P = 0.014) and T value (β = -0.12, 95% CI: -0.22 to -0.03, P = 0.013) per bout increase of SB bouts ≥ 60 min, respectively.

Limiting the duration of prolonged sedentary bouts and minimizing the occurrence of number of SB bouts ≥ 60 min could be essential in bone health management, especially for those older people who are overweight/obesity.