Abdominal obesity, liver fat and muscle composition in young adult survivors of childhood acute lymphoblastic leukemia.

摘要

Background. Survivors of childhood acute lymphoblastic leukemia (ALL) gain excess body weight in the years following therapy. We sought to determine whether cranial radiotherapy (CRT) and/or sex are associated with elevations in total and abdominal obesity, specifically visceral adipose tissue (VAT), as well as liver and muscle fat accumulation, and altered growth hormone (GH) and leptin status in young adults ALL survivors.; Methods. Abdominal AT, VAT, abdominal subcutaneous AT (SAT) masses were quantified from the L3-L4 to the L4-L5 inter-vertebral space using computed tomography (CT) in 52 male (15 CRT treated) and 62 female (24 CRT treated) young adult ALL survivors. The ratio of mean liver to mean spleen CT attenuation was used as a qualitative measure of liver fat infiltration. Mean muscle attenuation from 11 CT images spanning from 12-18 cm above the patella was used to indicate the degree of muscle fat deposition. Total fat and lean body mass were measured using dual energy x-ray absorptiometry (DEXA). Commercial radio-immunoassays were used to measure serum insulin growth factor-I (IGF-1) and leptin levels. IGF-1 levels were used as a surrogate measure of GH status.; Results. Controlled for age and race, CRT treated ALL survivors had higher VAT, body fat percentage, and leptin levels, but lower lean mass and IGF-1 levels as compared to non-CRT survivors (P 0.05). Among female survivors, CRT was associated with a significantly higher VAT: SAT ratio (P 0.01). Levels of IGF-I were inversely associated with total adiposity, VAT and VAT: SAT ratio in both sexes (P 0.01). Female ALL survivors had less lean mass and VAT but higher fat mass and SAT than males (P 0.05). Neither CRT nor sex was associated with muscle and/or liver fat content.; Conclusion. Among young adult ALL survivors, CRT is a risk factor for elevated total and abdominal obesity, visceral adiposity and reduced fat-free mass in association with an altered IGF-I and leptin levels.