Bone mineral metabolism, bone mineral density, and body composition in patients with chronic pancreatitis and pancreatic exocrine insufficiency.

Abstract

Calcium and vitamin D homeostasis seem to be abnormal in patients with exocrine pancreatic dysfunction resulting from cystic fibrosis. Only a few studies have evaluated and described bone mineral metabolism in patients with chronic pancreatitis and pancreatic insufficiency. Thirty-two patients with chronic pancreatitis and residual exocrine pancreatic function (group 1) and 26 patients with pancreatic exocrine insufficiency (i.e., meal-stimulated intraduodenal lipase <10% of lowest normal range and steatorrhea) (group 2) were studied. Serum levels of total calcium, phosphate, 25 (OH)D, 1.25(OH)2D, alkaline phosphatase, and parathyroid hormone were measured. Bone mineral density (BMD), bone mineral content (BMC), lean body mass (LBM), and fat mass (FM) were measured using a dual-energy X-ray absorptiometry (DXA) scanner. Alcohol was a causative factor in 79% of the patients. Fifty-six percent in group 1 and 69% in group 2 had Z-scores of the BMD < -1. The mean Z-score was -1.16 +/- 1.29 in group 1 and -1.32 +/- 0.90 in group 2. The mean Z-score of the BMC was -1.02 +/- 1.17 vs -1.39 +/- 0.987. In both groups mean 25 (OH)D and mean 1.25(OH)2D were below reference range. Plasma concentrations of albumin-corrected calcium, alkaline phosphatase, and parathyroid hormone were in the upper range of the reference range. Mean Z-scores of LBM were -0.69 +/- 1.34 in group 1 vs -1.01 +/- 1.12 in group 2 and Z-scores of FM were -0.27 +/- 1.70 in group 1 vs -0.95 +/- 1.01 in group 2 (p <0.05). Patients with chronic pancreatitis, in particular patients with advanced disease and steatorrhea, are at risk of developing significant bone loss. Despite normal body mass index the patients are characterized by loss of lean body mass and fat mass. The present study shows that these patients have decreased serum levels of vitamin D metabolites and low bone mass.