Endocrine Abstracts

Aim: Osteoporosis is common in postmenopausal women and in primary hyperparathyroidism (PHPT). PHPT is more prevalent in postmenopausal women. Aim of the present study was to investigate possible predictors of bone mineral density (BMD) in women with PHPT.

Methods: 166 consecutive women with PHPT [age: 59.5±13.5 years; Asymptomatic/Symptomatic: 84/82; premenopausal/postmenopausal: 31/135; BMI: 25.6±4.8 kg/m²; PTH: 234.2±287.3 pg/ml; Calcium: 11.2±1.2 mg/dl] were studied. Serum levels of calcium, phosphate, intact parathyroid hormone (PTH), 25 hydroxy-vitamin D (25OHD3), creatinine and creatinine clearance (Ccr) were analyzed and bone densitometry was performed at lumbar spine, hip and forearm.

Results: In univariate analysis, age and menopausal status were negatively related with BMD and T-score at any site. BMI was positively associated with BMD and T-score at femur. PTH levels were negatively associated with T-score and BMD at forearm and lumbar spine, whereas ionized calcium at all the three sites. 25OHD3 was positively associated with BMD at lumbar spine and forearm. Ccr was positively associated with BMD and T-score at all the three sites. In multivariate regression analysis, menopausal status resulted an independent predictor of T-score at any site (forearm: ß=−0.31, P<0.00001; femur: ß=−0.21, P<0.006; lumbar: ß=−0.17, P=0.025), while PTH was an independent predictor of T-score at forearm (ß=−0.33, P=0.010) and lumbar spine (ß=−0.30, P=0.037). Ionized calcium also independently associated with forearm T-score (ß=−0.23, P=0.0025) while Ccr with T-score at forearm (ß=0.15, P=0.035, respectively) and femur (ß=0.24, P=0.0016).

Conclusions: In women with PHPT, menopausal status represents one of the most important predictors of bone mass. However, other factors related to the disease such as PTH, calcium levels or renal function, can each other influence independently bone mass, mainly at cortical level.