The Relationship between Serum Levels of Leptin and Bone Mineral Density in Patients with Chronic Liver Diseases

Abstract

Metabolic bone diseases in the form of osteoporosis are important complication of chronic liver disease and many risk factors have been implicated in its development in such group of patients. Leptin has emerged as a major factor linking food intake with bone metabolism. Leptin can regulate bone formation through both central (hypothalamic) and peripheral (direct) pathways, and leptin deficiency, in the form of either caloric restriction or a congenital absence of leptin, is associated with low bone mass. From this point we designed our study to detect the relationship between circulating level of leptin and BMD in patients with CLD, that included 50 patients with CLD (35 males and 15 females) with Mean age 52.30 ± 12.47 years, and 20 healthy controls (6 males and 14 females) with Mean age 53.25 ± 8.43years. All patients underwent history taking and clinical examination. Laboratory investigations were done including AST, ALT, ALP, bilirubin, PT, albumin, Calcium and phosphorus, CBC, complete urine analysis and serum urea and creatinine, and radiological examination included X-ray of the thoraco-lumbar spine and abdominal ultrasound. Serum leptin, BMI and BMD were measured for both patients and controls. Data were collected, tabulated and statistical analysis was done and revealed higher frequency of osteoporosis among patients with CLD (48%) compared to control with only 5% had osteoporosis. We recorded, trabecular bones are affected more frequently and severely than cortical bones (mean T-score at lumbar spine was -2.21 ± 1.46 compared to -1.14 ± 1.41 at femoral neck, 44% had osteoporosis at lumbar spine compared to 20% at femoral neck). We recorded absence of significant association between degree of bone loss and severity of CLD according to Child-Pugh score and classification. In our study serum leptin level in patients ranged from 1.20 – 100.0 ng/mL with Mean ± SD 15.93 ± 23.02, while in controls the range was 1.20 to 90.0 ng/mL with Mean ± SD 26.40 ± 25.69. Despite lower serum leptin level in chronic liver disease patients compared to controls, there was no statistically significant difference between them with p value 0.079. In our study there was no significant association between serum leptin level and age or gender in CLD patients. We reported no significant association between serum leptin level and severity of liver disease according to Child-Pugh score, and no significant correlation with direct bilirubin, PT, and albumin.