Objective: To assess the relationship between thyrotoxicosis and osteoporotic fractures in men and women.
Design: Register-based cohort study in patients with a TSH measurement in the region of Funen 19962010. All determinations were done in the same lab serving all hospitals and GP practices. Persons with raised TSH or a history of thyroid/pituitary disease were not included.
Results: The study population consisted of 222 138 (96%) persons with normal and 9217 (4%) with low TSH. During a median follow-up of 7.5 years, 13.5% of the low TSH group and 6.9% of the normal TSH group sustained major osteoporotic fractures (MOF), P<0.01. A single, low TSH at baseline was associated with increased risk of hip fractures (Table 1) but less strongly with MOF (HR 1.06, 95% CI 0.991.12, P=0.058). There was a significant association also with duration of thyrotoxicosis. In euthyroid patients, the risk of hip fractures (HR 1.45, 95% CI 1.221.71, P<0.001) and MOFs (HR 1.32, 95% CI 1.191.46, P<0.001) increased with each SD unit of TSH decrease.
|Single, low TSH measurement||Per 6 mo of low TSH|
|All||1.16 (1.071.26); P<0.01||1.07(1.041.10); P<0.01|
|Women||1.17 (1.061.28); P<0.01||1.07 (1.041.10); P<0.01|
|Men||1.17 (0.951.42); P=0.1||1.07 (0.991.14); P=0.05|
Conclusion: In a population-based cohort, a single, first measurement of decreased TSH in a patient without known thyroid disease was associated with an increased long term risk of hip fracture, which remained significant in women but not in men after adjusting for confounders. Moreover, the risk of both hip fracture and MOF increased exponentially by the length of time during which TSH had remained low.
17 May 2014 - 20 May 2014