Introduction:Prior research has indicated a correlation between hypothalamic-pituitary endocrine secretion and bone health. However, the relationship between thyroid hormone levels and lumbar spine bone density in adults remains incompletely understood. The objective of the present study was to examine this relationship and to assess the moderating effects of factors such as gender, age, and depressive symptoms on it.
Methods:Cross-sectional analyses were conducted using data from the National Health and Nutrition Examination Survey (NHANES), conducted between 2007 and 2012. Weighted linear regression models and multiple logistic regression models were employed to evaluate the correlation between lumbar spine bone density and indicators of thyroid function in 4996 adults aged 20-80 years. Additionally, the study investigated the effect of thyroid hormones on lumbar spine bone density in depressed adults.
Results and conclusions:In adults, a significant negative correlation was observed between lumbar spine bone density and FT3 levels, but not with any of the other thyroid hormones. The correlation between lumbar bone density and TT3, TT4, and Tg was found to be interactive with regard to gender. No significant interaction was observed between age and depressive symptoms with regard to lumbar bone density and thyroid hormones. Subgroup analyses revealed that the inverse relationship between bone mineral density (BMD) and free triiodothyronine (FT3) was exclusive to younger adults and was not statistically significant in older adults. In the fully adjusted model, a significant negative correlation was observed between BMD and TT4 in adult males (p=0.027), whereas no significant correlation was identified in adult females. In the fully adjusted model, BMD was significantly negatively correlated with FT4 and FT3 in non-depressed patients (p=0.040, p=0.027). Additionally, it was found that although thyroid hormones correlate with both depression and BMD, thyroid hormones do not cause changes in BMD solely because of depressive states. Therefore, further comprehensive research is required to elucidate the specific mechanism of hypothalamic-pituitary-thyroid on bone health.
