THE RISK OF HIP-FRACTURES IN PATIENTS WITH PRIMARY HYPERPARATHYROIDISM - A POPULATION-BASED COHORT STUDY WITH A FOLLOW-UP OF 19 YEARS

Objective. To evaluate primary hyperparathyroidism (HPT) as a risk fac tor for hip fractures. Design. A population-based, record-linked, pros pective 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. Parti cipants. All patients (1373 women and 551 men) who were admitted to ho spital with the diagnosis of HPT during the period. Comparisons were m ade with the entire background population. Measurements. Cohort subjec ts 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 co mpared with that expected on the basis of person-years of observation and incidence rates in the background population. Analyses were made f or cervical and trochanteric fractures, and for patients operated and not operated for HPT. Main results. (i) Women. During 23341 person-yea rs 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 troch anteric fractures 1.33 (CI 0.88-1.93). Operation for HPT did not influ ence the risk of hip fracture. (ii) Men. The total person-years was 90 91. 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 c ervical hip fractures (RR 2.73; CI 1.18-5.39). Owing to the few fractu res in this group (n = 8) the relevance of this is uncertain. Conclusi ons. This study indicates that HPT is not a risk factor for hip fractu res in women.