The risk of hip fractures in patients with primary hyperparathyroidism: a population-based cohort study with a follow-up of 19 years.

Abstract

OBJECTIVE: To evaluate primary hyperparathyroidism (HPT) as a risk factor for hip fractures. DESIGN: A population-based, record-linked, prospective study with a mean observation time of 17 years (women) and 16.5 years (men). SETTING: A cohort obtained from a register of hospital admissions in the Uppsala Health Care Region, Sweden, 1965-1983. PARTICIPANTS: All patients (1373 women and 551 men) who were admitted to hospital with the diagnosis of HPT during the period. Comparisons were made with the entire background population. MEASUREMENTS: Cohort subjects were followed with regard to a first instance of hip fracture prior to or after the diagnosis of HPT. The observed number of cases was compared with that expected on the basis of person-years of observation and incidence rates in the background population. Analyses were made for cervical and trochanteric fractures, and for patients operated and not operated for HPT. MAIN RESULTS: (i) Women. During 23,341 person-years of observation, 67 cases of first hip fractures occurred, yielding a relative risk (RR) of 0.93 (95% confidence interval [CI] 0.72-1.19). The RR for cervical fractures was 0.77 (CI 0.54-1.06), and for trochanteric fractures 1.33 (CI 0.88-1.93). Operation for HPT did not influence the risk of hip fracture. (ii) Men. The total person-years was 9091. Eleven fractures were observed--compared with the expected 7.90 (RR 1.39; CI 0.69-2.50). Men operated for HPT had an increased risk for cervical hip fractures (RR 2.73; CI 1.18-5.39). Owing to the few fractures in this group (n = 8) the relevance of this is uncertain. CONCLUSIONS: This study indicates that HPT is not a risk factor for hip fractures in women.