Endocrine Abstracts

Introduction: It has been reported that vitamin D deficiency is common in patients with primary hyperparathyroidism (pHPT), and this could affect the clinical expression of the disease. However only few studies addressed this issue and refer to American or North European patients. In these studies, only about one third of the patients showed a vitamin D replete state.

Subjects and methods: In 207 consecutive pHPT patients (M/F=45/162, age (mean ±S.D.): 60.1±13.6 years, PTH=216.1±202.8 pg/ml, calcium=11.1±1.2 mg/dl, asymptomatic/symptomatic=89/118)) we have assessed vitamin D status by measuring plasma 25-OH vitamin D (25-OHD) levels. Vitamin D deficiency was defined as 25-OHD <20 ng/ml, whereas vitamin D insufficiency was defined as 25-OHD >20 to <30 ng/ml.

Results: In our series 36.2% of the patients showed 25-OHD deficiency and 21.3% showed 25-OHD insufficiency. 37% of female patients resulted 25-OHD deficient and 19.8% insufficient. 33.3% of male patients resulted 25-OHD deficient and 26.7% insufficient. 38.1% of symptomatic patients resulted 25-OHD deficient and 22.1% insufficient. 33.7% of asymptomatic patients resulted 25-OHD deficient and 20.2% insufficient. 25-OHD levels were significantly related with BMD at forearm, at femur and at spine (R=0.27, P<0.0003 at forearm; R=0.16, P<0.04 at femur, R=0.20, P<0.009 at lumbar spine). Moreover 25OHD-levels were negatively related with PTH (R=−0.38, P<0.000001), calcium (R=−0.27, P<0.00009) and bone turnover markers levels (R=−0.21, P<0.003 for osteocalcin, R=−0.38, P<0.0004 for cross-links). No seasonal variability was observed in 25-OHD levels.

Conclusions: In this ‘Southern European’ pHPT case series the proportion of 25OHD deficiency is lower than that reported for North American and North European studies. These differences could be due to the different latitude/skin UV exposure. 25-OHD status is related to biochemical indexes of the disease but it does not seem to affect classical pHPT manifestations.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.