Bone Mass, Vitamin D Deficiency, and Hyperparathyroidism in Congestive Heart Failure

Abstract

PURPOSE: In contrast to renal and hepatic failure, congestive heart failure (CHF) has not been associated with a defined metabolic bone disorder. However, low bone mass has been reported in patients with CHF who receive a cardiac transplant. Both the pathophysiology and therapy of CHF may influence bone and mineral homeostasis and evidence that calciotropic hormones may affect cardiovascular function is accumulating. Therefore, we evaluated patients with severe CHF to determine the prevalence of osteoporosis and to characterize relationships between mineral homeostasis, bone turnover, bone mass, and severity of CHF. PATIENTS AND METHODS: One hundred one patients (79 men and 22 women, aged 25 to 70 years) with severe CHF (New York Heart Association functional class III or IV) referred for consideration for cardiac transplantation were evaluated with measurements of serum 25-hydroxyvitamin D (25-OHD), 1,25 dihydroxyvitamin D [1,25(OH)2D], intact parathyroid hormone (PTH), markers of bone turnover (serum osteocalcin, urinary hydroxyproline, and pyridinium crosslinks); bone mineral density (BMD) by dual energy x-ray absorptiometry was measured in 91 patients. Left ventricular ejection fraction (LVEF) and resting cardiac output (CO) were determined in 88 and maximal treadmill exercise testing and peak oxygen consumption were performed in 45 patients. RESULTS: Osteoporosis (T score < or = -2.5) was present in 7% at the lumbar spine, 6% at the total hip, and 19% at the femoral neck. Osteopenia (T scores between -1.0 and -2.5) was present in 43% at the lumbar spine, 47% at the total hip, and 42% at the femoral neck. Women were more severely affected (P = 0.007). Frankly low serum 25-OHD (< or = 9 pg/mL) and 1,25(OH)2D (< or = 15 pg/mL) levels were found in 17% and 26% of the patients, respectively, and elevated serum PTH (> or = 65 pg/mL) in 30%. Both low serum 1,25(OH)2D and increased serum PTH were associated with prerenal azotemia. Low serum vitamin D metabolites were associated with biochemical evidence of increased bone turnover, but BMD did not differ by vitamin D or PTH status. Patients with more severe CHF had significantly lower vitamin D metabolites and higher bone turnover, whereas elevated PTH was associated with better LVEF (21 +/- 1 versus 18 +/- 1%; P = 0.05) and correlated positively with resting CO (R = 0.220; P = 0.04). CONCLUSIONS: Osteopenia or osteoporosis were observed in approximately half of these patients with severe CHF. Abnormal calciotropic hormone concentrations, also common, were associated with evidence of increased bone resorption but were not related to BMD in this cross-sectional study. Abnormal concentrations of calciotropic hormones were related to the severity of cardiovascular compromise. Because both low BMD and low serum concentrations of 25-OHD in patients with CHF are associated with higher rates of bone loss and fracture after cardiac transplantation, patients should be evaluated for and receive appropriate therapy for these disorders.