Sex-specific association between dietary carbohydrate intake and bone mineral density among American adolescents: National Health and Nutrition Examination Survey.

BACKGROUND

The association between dietary carbohydrate intake and bone mineral density (BMD) remains controversial, and research on this topic among adolescents is lacking. This study aimed to examine the relationship between dietary carbohydrate intake and BMD in adolescents.

METHODS

This study examined data from adolescents (12-19 years) in the National Health and Nutrition Examination Survey (NHANES) (2005-2010). Dietary carbohydrate intake was assessed via two 24-hour recalls. BMD at the lumbar spine, total spine, total femur, and femoral neck was measured by dual-energy X-ray absorptiometry (DXA). A two-day dietary weighted multivariate regression analysis was employed to adjusted for covariates and assess the relationship between carbohydrate intake and BMD. The consistency of the associations and potential modifying factors were further evaluated through stratification and interaction analyses, both weighted by the two-day dietary data. Additionally, stratified curve fitting elucidated sex-specific differences in this relationship.

RESULTS

After excluding missing data, 2616 adolescents aged 12-19 years were included in the study. In the fully adjusted two-day dietary sample weighted analysis model, a positive association was observed between dietary carbohydrate intake and BMD among all participants. Dietary carbohydrate intake was positively associated with lumbar spine BMD (β = 1.31, 95 % CI = 0.38-2.23), total spine BMD (β = 1.31, 95 % CI = 0.39-2.24), and femoral neck BMD (β = 0.91, 95 % CI = 0.05-1.77) among all participants. Subgroup analyses revealed a significant sex interaction effect (P < 0.05). Subsequently, stratified curve fitting and sex-specific multivariate regression analyses were conducted. The results indicated a positive correlation between dietary carbohydrate intake and BMD in males, whereas no such correlation was observed in females. The multivariate analysis results further confirmed the sex-specific differences in the relationship between dietary carbohydrate intake and BMD, consistent with the initial findings.

CONCLUSION

Our study demonstrated that carbohydrate consumption significantly enhances BMD during adolescent bone growth. This effect is sex-specific.