Low Thyroid Stimulating Hormone Levels Are Associated with Low Bone Mineral Density in Femoral Neck in Elderly Women.

BACKGROUND AND AIMS: To determine the relationship between thyroid stimulating hormone (TSH) and bone mineral density (BMD) in elderly women.

METHODS: This is a retrospective cross-sectional population cohort study of women aged ≥65 years. All 1097 subjects had no overt thyroid dysfunction, 47 had subclinical hyperthyroidism and 100 had subclinical hypothyroidism. Overall, 167 had normal BMD, 594 had osteopenia and 336 had osteoporosis.

RESULTS: The femoral neck (FN) BMD was lower in women with lower TSH, with a high prevalance of osteoporosis and osteopenia (p = 0.036).The prevalence of osteoporosis and osteopenia was significantly low in the lowest quartile compared with the third quartile (p = 0.023) and the fourth quartile (p = 0.002), and the second low quartile, compared with the fourth quartile (p = 0.028). The differences were not significant among subclinical hyperthyroid, subclinical hypothyroid and euthyroid women. Low TSH was related to low BMDs at FN by multiple logistic regression analysis corrected for age and BMI. TSH in the lower two quartiles were independently related to osteoporosis (OR: 1.960, p = 0.023 and OR: 1.800, p = 0.037) and osteopenia (OR: 2.108, p = 0.005 and OR: 1.723, p = 0.030). Low TSH quartile (β: 0.007, p = 0.013) predicting low BMDs at FN.

CONCLUSION: Low TSH was independently related to decreased BMDs at FN in elderly women without overt thyroid dysfunction.