Epidemiology of Primary Hyperparathyroidism and its Non-classical Manifestations in the City of Recife, Brazil

Before the introduction of routine measurements of serum calcium in ambulatory services, PHTP (primary hyperparathyroidism) was symptomatic with classic bone disease (known as osteitis fibrosa cystica) nephrolithiasis, and acute neuropsychiatric syndrome with severe hypercalcemia. Currently, PHPT presents few unspecific symptoms. This cross-sectional study was conducted from December 1, 2007, through August 31, 2008 to estimate the prevalence of primary hyperparathyroidism and to describe the clinical and laboratory characteristics of patients receiving ambulatory care. From 4207 patients, we found a prevalence of PHTP of 0.78 (95% confidence interval [CI], 0.52-1.04) of which 81.8% were asymptomatic and 18.2% symptomatic. The female:male ratio was 7.2:1, and 89.7% of the women were postmenopausal. Mean age was 61.12 ± 15.73 years, mean serum calcium was 10.63 ± 1.33 mg/dL, and mean serum parathyroid hormone (PTH) was 182.48 ± 326.51 pg/mL. We found a high prevalence of PHTP at reference centers and a high prevalence of hypertension and type 2 diabetes.