Primary Hyperparathyroidism: The Influence of Bone Marrow Adipose Tissue on Bone Loss and of Osteocalcin on Insulin Resistance

Abstract

OBJECTIVES:Bone marrow adipose tissue has been associated with low bone mineral density. However, no data exist regarding marrow adipose tissue in primary hyperparathyroidism, a disorder associated with bone loss in conditions of high bone turnover. The objective of the present study was to investigate the relationship between marrow adipose tissue, bone mass and parathyroid hormone. The influence of osteocalcin on the homeostasis model assessment of insulin resistance was also evaluated.METHODS:This was a cross-sectional study conducted at a university hospital, involving 18 patients with primary hyperparathyroidism (PHPT) and 21 controls (CG). Bone mass was assessed by dual-energy x-ray absorptiometry and marrow adipose tissue was assessed by 1H magnetic resonance spectroscopy. The biochemical evaluation included the determination of parathyroid hormone, osteocalcin, glucose and insulin levels.RESULTS:A negative association was found between the bone mass at the 1/3 radius and parathyroid hormone levels (r = -0.69; p<0.01). Marrow adipose tissue was not significantly increased in patients (CG = 32.8±11.2% vs PHPT = 38.6±12%). The serum levels of osteocalcin were higher in patients (CG = 8.6±3.6 ng/mL vs PHPT = 36.5±38.4 ng/mL; p<0.005), but no associations were observed between osteocalcin and insulin or between insulin and both marrow adipose tissue and bone mass.CONCLUSION:These results suggest that the increment of adipogenesis in the bone marrow microenvironment under conditions of high bone turnover due to primary hyperparathyroidism is limited. Despite the increased serum levels of osteocalcin due to primary hyperparathyroidism, these patients tend to have impaired insulin sensitivity.

Primary hyperparathyroidism in young patients is associated with metabolic disorders: a prospective comparative study

“…But after PTE osteocalcin levels had significantly decreased, while HOMA2-S% did not change [16]. Mendonça M. L. et al did not observe associations between osteocalcin and insulin, glucose levels, HOMA-IR in PHPT group [17]. Therefore, the role of bone remodeling in metabolic processes requires further investigation.…”

Primary Hyperparathyroidism in Young and Middle-age Patients is Associated With Metabolic Disorders: a Prospective Comparative Study

“…This is similar to Chinese study that showed an inverse relationship between serum osteocalcin levels and visceral fat area (26). Mendonça M. L. et al didn't observe associations between osteocalcin and insulin, glucose levels, HOMA-IR in PHPT (27). Therefore the role of bone remodeling in metabolic processes requires further investigation.…”

Metabolic features of young patients with primary hyperparathyroidism

“…Mendonça M.L. et al также при сравнении небольшой группы пациентов с ПГПТ в возрасте 51,1±11,3 года и здорового контроля описывают более высокий уровень остеокальцина и тенденцию к развитию ИР (на основе расчета индекса HOMA-IR) при патологии ОЩЖ, однако статистически значимых связей между перечисленными параметрами исследователи не обнаружили [19]. Напротив, в другом исследовании у больных ПГПТ среднего возраста (n=219) остеокальцин отрицательно коррелировал с глюкозой натощак и положительно -с индексом HOMA2-S% [20].…”