Thyroid function and bone mineral density among Indian subjects.

Area of Science:

• Endocrinology
• Bone Metabolism
• Mineral Density

Background:

• Thyroid hormones influence bone remodeling.
• Limited data exists on thyroid function and bone mineral density (BMD) in euthyroid individuals.
• This study investigates thyroid function's correlation with BMD in euthyroid and subclinically hypothyroid subjects.

Purpose of the Study:

• To evaluate the correlation between thyroid function and BMD.
• To assess the impact of normal thyroid function and subclinical hypothyroidism on BMD.
• To explore the relationship between thyroid hormones (TSH, FT4, FT3) and BMD.

Main Methods:

• Cross-sectional study of 1290 subjects divided into normal thyroid function and subclinical hypothyroidism groups.
• Assessed serum levels of 25(OH)D, parathyroid hormone, calcium, phosphorus, and alkaline phosphatase.
• Measured BMD at the lumbar spine, femur, and forearm.

Main Results:

• BMD was comparable across all measured sites (radius, femur, spine) between groups.
• No significant difference in BMD was observed when subjects were stratified by TSH tertiles.
• In euthyroid subjects, FT4 and TSH positively associated with radius BMD, while FT3 negatively associated with femoral neck BMD.
• In subclinically hypothyroid subjects, no TSH-BMD association was found.
• Across all subjects, FT4 and FT3 positively correlated with lumbar spine and radius BMD, respectively.

Conclusions:

• Thyroid stimulating hormone (TSH) does not influence BMD in euthyroid or subclinically hypothyroid individuals.
• Thyroid hormones demonstrate a more significant positive impact on cortical bone compared to trabecular bone in euthyroid subjects.