HIP-FRACTURES AND THE THYROID - A CASE-CONTROL STUDY

Objective. To investigate the prevalence of thyroid illness - especial ly hyperthyroidism - and exposure to thyroid hormones in patients with hip fracture. Design. A case-control study. Setting. Two surgical/ort hopaedic hospital units and 22 facilities for the aged in a moderately iodine-deficient region of Germany. Subjects. A total of 116 postmeno pausal females with hip fracture and 402 postmenopausal female control s. Main outcome measures. Hip fracture; thyroid disease confirmed by m easurement of serum thyrotropin, total and free thyroxine and triiodot hyronine; history of thyroid disease and thyroid medication obtained b y a questionnaire. Results. Of the hip fracture patients 4.3% had over t untreated hyperthyroidism, and 6.9% gave a history of past hyperthyr oidism (total, 11.2%), The corresponding figures for the controls were 2.0 and 2.7%, respectively (total, 4.7%). 7.8% of the cases had been exposed to levo-thyroxine for 3-29 years, compared to 11.2% of the con trols. The odds ratio for hyperthyroidism (present and past) was 2.5 ( 1.2-5.3, 95% confidence interval), and the odds ratio for levothyroxin e exposure was 0.67 (0.32-1.41) in the hip fracture patients. Conclusi ons. Hyperthyroidism is found 2.5-fold more often in hip fracture pati ents than in controls. Hence, hyperthyroidism appears to be a signific ant risk factor for hip fracture and should be investigated by clinica l and, when necessary, laboratory means in hip fracture patients. In c ontrast, no increased risk for hip fracture could be detected after ex posure to levothyroxine.