Disturbances of Calcium Homeostasis Consistent with Mild Primary Hyperparathyroidism in Premenopausal Women and Associated Morbidity

Abstract

Primary hyperparathyroidism (PHPT) and associated morbidity are comprehensively assessed in elderly females; however, less is known of the disease in younger women. Our objectives were to estimate the prevalence of mild disturbances in calcium homeostasis, which could be analogous with early PHPT, in a premenopausal population, and determine the potential presence of associated morbidity. Initial results from this longitudinal study are from 2002-2004. We conducted a population-based screening of serum (s)-calcium in conjunction with routine mammography. Participants included premenopausal women, 40-50 yr of age (n = 1900). Cases fulfilling previously evaluated biochemical criteria for PHPT (n=214) were matched to controls (n = 214). All participants underwent investigation, including screening of parameters of calcium homeostasis, dual x-ray absorptiometry, and body mass index assessment, and filled out extensive health and quality of life (SF-36) questionnaires. Participants were divided into four groups depending on the relation between s-calcium/intact PTH. Statistical comparisons between cases and controls as well as among the four groups were performed to evaluate morbidity. The prevalence of assumed mild PHPT, i.e. inappropriate intact PTH value in relation to total s-calcium, was estimated to be 5.1% (n = 96). Women with mild disturbances in calcium homeostasis had statistically significant lower bone mineral density in the proximal femur and femoral neck, higher body mass index, and lower scores for vitality and general health in the analysis of SF-36. Mild disturbances in calcium homeostasis in premenopausal women were more prevalent than previously thought and were associated with obesity, lower bone mineral density, and decreased quality of life.