Evaluation of vitamin D status bone mineral density and dental health in children with cholestasis.

BACKGROUND: Hepatic osteodystrophy caused by vitamin D and calcium malabsorption is thought to develop in children with cholestatic liver disease leading to secondary hyperparathyroidism and rickets or osteomalacia. The aim of this study was to evaluate the dental and bone mineral densities and the serum level of vitamin D in cholestatic infants and children and to correlate this process with clinical and laboratory parameters.

METHODS: This is a cross-sectional study that include 50 patients presenting with cholestasis. Thirty age and sex matched controls recruited not complaining of liver disease. All cases were subjected to full history taking, clinical and dental examination, 25(OH)D level, ALT, AST, bilirubin, albumin, GGT, alkaline phosphatase, PT, INR, calcium, corrected calcium, phosphorus and DXA scan to those above 5 years old. Controls were subjected to measuring the serum levels of 25(OH)D, total bilirubin, direct bilirubin, ALT, GGT, AST, PT, INR, alkaline phosphatase, albumin, calcium and phosphorus.

RESULTS: Out of the 50 cases; 23 were females (46%), with a mean age of 6.17±3.9 years ranging from 1.1 to 17 years. Twenty-eight of the cases had signs of rickets (56%), 6 of them had bone fracture (12%) and 42.8% had milky teeth caries. The level of 25(OH) vitamin D was below normal range in around half of the patients. There was significant difference between cases and controls in calcium and phosphorus levels, ALT and alkaline phosphatase. Low bone mineral density (BMD) was present in 50% and 5 cases (17.9%) were diagnosed as having osteoporosis. There was a negative correlation between the Z-score, BMD of total body, BMD and bone mineral content (BMC) of spine and total and direct bilirubin. There was a positive correlation between (BMD of total body, spine and BMC of spine) and serum phosphorus, alkaline phosphatase and albumin. There was a positive correlation between the Z-score of total body and serum calcium.

CONCLUSION: Decreased level of 25-OH vitamin D is present in more than half of cholestatic patients, and is correlated positively to serum calcium. Decreased BMD was present in more than half of studied cholestatic patients correlated to the low serum calcium rather than the vitamin D level. The decreased BMD and the dental affection in cholestatic children is related to the level of hyperbilirubinemia.