Duration of television viewing and bone mineral density in Chinese women

Studies on the relationship between television (TV) viewing and bone mineral density (BMD) in adults are limited. The purpose of this study was to examine whether longer duration of TV viewing increased the risk of lower BMD in Chinese women. A total of 626 female adults were voluntarily recruited into the study. Anthropometric measurements were obtained using standard procedures. Body composition including total body and regional BMD was estimated using dual-energy X-ray absorptiometry. The duration of TV viewing was categorized into 4 groups: <1 h, 1 to <2 h, 2 to <3 h, and ≥3 h. Multiple linear regression models were applied to analyze the associations between duration of TV viewing and total and regional BMD in all subjects and in subjects stratified by age of 45 years, respectively. After adjusting for age, BMI, alcohol use, smoking, education, income, urbanicity, leisure time physical activity, occupational physical activity, and menopause, the significant trend of pelvic BMD across categories of TV viewing was observed in all subjects (p < 0.05). Further analysis revealed that women aged <45 years, the 1 to <2 h group, the 2 to <3 h group, and the ≥3 h group were significantly associated with lower total body and regional BMD compared to women aged <45 years in the <1 h group. We concluded that the duration of TV viewing was negatively associated with BMD in Chinese women, especially in those aged 18-44 years. It might be sensible to reduce TV viewing time to prevent bone loss in young women.