Sex Difference in the Clinical Presentation of Primary Hyperparathyroidism: Influence of Menopausal Status

Context: Female-to-male ratio in primary hyperparathyroidism (PHPT) is 3:1, but data on sex impact on the clinical presentation are limited. Design: We evaluated, retrospectively, sex difference in biochemistry and clinical presentation at diagnosis in a monocentric series of 417 patients with PHPT: 93 men (58.6 +/- 14.5 years), and 324 women (61.7 +/- 12.8 years), of whom 54 were premenopausal (pre-F) and 270 postmenopausal (post-F). Results: Men were significantly younger (P = 0.046) and more frequently symptomatic than women (62.3% vs 47%, P = 0.016). No sex difference was found in serum parathyroid hormone, calcium, creatinine, 25-hydroxy-vitamin D, and urinary calcium levels, whereas serum phosphate was higher in women. Nephrolithiasis (detected by imaging or history of passing stones) was more frequent in men (50.5% vs 33% in women, P = 0.003) and osteoporosis (T-score <-2.5 at any site) was more frequent in women (52.2% vs 35.5% in men, P = 0.0066). Symptomatic patients were 43.3%, 64.8%, and 62.3% in post-F women, pre-F women, and men, respectively. Kidney stones were less frequent and osteoporosis more frequent in post-F women than in pre-F women (28.1% vs 59.2% and 58.9% vs 18.5%, respectively). After combining symptomatic and asymptomatic patients meeting surgical criteria recommended by current guidelines, no sex difference was observed in the proportion of patients to be referred for surgery (84.6% in men vs 84.9% in women). Conclusion: Biochemical activity of PHPT seems to be independent of sex, but clinical presentation is different, mostly due to menopausal state. However, surgical referral was indicated equally in men and women.