Weight gain is accompanied by increasing TSH, and weight loss in women is related to decreasing TSH.

Objective: To study the relationship between TSH and forearm bone mineral density (BMD) in a general female population. Design: Cross-sectional, population-based study. Methods: In a substudy of the Nord-Trøndelag Health Study 1995-1997 (HUNT 2), 5778 women without and 944 with self-reported thyroid disease aged R40 years had their serum TSH and distal and ultra-distal forearm BMD measured. In range-based categories of TSH, excluding women with previous thyroid disease, a general linear model was used to calculate adjusted mean BMD, and a logistic regression model to compute adjusted odds ratio (OR) for osteopenia and osteoporosis. Corresponding models were used to compare BMD in women with self-reported hypothyroidism or hyperthyroidism to euthyroid women. Results: In women without self-reported thyroid disease, those with TSH !0.5 mU/l had 10.7 mg/cm 2 (95% confidence interval (CI) 0.2-21.1) lower distal and 9.1 mg/cm 2 (95% CI K0.7-18.9) lower ultra-distal BMD than women in the reference category (TSH 0.50-1.49 mU/l). No differences were found between the categories with TSH R0.50 mU/l. Compared to self-reported euthyroid women, self-reported hyperthyroid women had increased odds for osteoporosis both distally (OR 1.35, 95% CI 1.00-1.82) and ultra-distally (OR 1.48, 95% CI 1.10-1.99). Conclusion: Women with the lowest TSH (!0.5 mU/l) had lower forearm BMD than the reference category. No differences were observed between the TSH categories R0.50 mU/l. The prevalence of osteoporosis was higher in women who reported hyperthyroidism than in women without selfreported thyroid disease.

Objective: To prospectively study the relation between TSH and risk of hip and forearm fractures. Design: A population-based cohort study. Methods: In a substudy of the second survey of the Nord Trøndelag Health Study, Norway (HUNT2, 1995-97), linked with a hospital-based fracture registry, we investigated the relation between baseline TSH and risk of hip and/or forearm fractures. Population: A total of 16 610 women and 8595 men aged 40 years or more, without previous self-reported thyroid disease and hip or forearm fractures. Results: During 12.5 years follow-up, a total of 1870 women and 342 men experienced hip or forearm fractures. Overall, there was no relation between baseline TSH and fracture risk. However, there was weak evidence that women with TSH !0.5 and O3.5 mU/l had a slightly increased risk of hip fractures (hazard ratio (HR) 1.30, 95% CI 0.97-1.94 and HR 1.19, 95% CI 0.93-1.52) compared with the reference group with TSH of 1.5-2.4 mU/l. Supplementary analyses showed higher hip fracture risk in women with TSH O4.0 mU/l and negative thyroid peroxidase antibodies (TPOAb) compared with the reference group (HR 1.75, 95% CI 1.24-2.46). Conclusion: We found no statistically significant relation between baseline TSH and subsequent fracture risk, but the data suggest a weak positive association with hip fracture risk among women with both low and high TSH. The latter association was confined to women with negative TPOAb status.