Epidemiology of primary hyperparathyroidism in Tayside, Scotland, UK

To evaluate prevalence and incidence of diagnosed primary hyperparathyroidism (PHPT) in adults between 1997 and 2006 in Tayside, Scotland, UK.

Population-based incidence and prevalence study.

All Tayside residents aged 20 years and over with an increased serum calcium level (> 2.55 mmol/l) between 1997 and 2006 were included as potential participants. Using a unique patient identifier, data-linkage enabled a data set of PHPT patients to be created from an algorithm of biochemistry records, nuclear scan records, histology records, hospital clinic letters and community based prescription records. Persons having tertiary hyperparathyroidism (14.0%) were also identified and were excluded.

Age and sex adjusted incidence density and period prevalence were calculated for each year.

We identified 2709 patients (70.8% female) diagnosed with PHPT by the end of 2006. The mean age of women (68 years SD = 14) was older than that of men (64 years SD = 15) at baseline. The prevalence of diagnosed PHPT in Tayside increased from 1.82 per 1000 population in 1997 to 6.72 per 1000 population in 2006 (P < 0.001). Prevalence of PHPT is higher in females, and the female preponderance increases with age; the annual prevalence ratio between women and men is stable at around 2.5 each year. There was a 3-4-year cyclical incidence rate varying from 4.13 to 11.30 per 10 000 person-years.

We observed a general increase in the prevalence of diagnosed PHPT in Tayside, Scotland. The incidence of diagnosis is greater in females than in males and increases with age. The annual incidence followed an apparent cyclic curve during the study period.