Relationship between adiponectin and leptin on osteocalcin in obese adolescents during weight loss therapy

ABSTRACT Objectives: Obesity is a multifactorial disease characterized by the presence of the pro-inflammatory state associated with the development of many comorbidities, including bone turnover marker alterations. This study aimed to investigate the role of the inflammatory state on bone turnover markers in obese adolescents undergoing interdisciplinary weight loss treatment for one year. Subjects and methods: Thirty four post-pubescent obese adolescents with primary obesity, a body mass index (BMI) greater than > 95th percentile of the CDC reference growth charts, participated in the present investigation. Measurements of body composition, bone turnover markers, inflammatory biomarkers and visceral and subcutaneous fat were taken. Adolescents were submitted to one year of interdisciplinary treatment (clinical approach, physical exercise, physiotherapy intervention, nutritional and psychological counseling). Results: Reduction in body mass, body fat mass, visceral and subcutaneous fat, as well as, an increase in the body lean mass and bone mineral content was observed. An improvement in inflammatory markers was seen with an increase in adiponectin, adiponectin/leptin ratio and inteleukin-15. Moreover, a positive correlation between the adiponectin/leptin ratio and osteocalcin was demonstrated. Further, both lean and body fat mass were predictors of osteocalcin. Negative associations between leptin with osteocalcin, adiponectin with Beta CTX-collagen, and visceral fat with adiponectin were observed. Conclusions: It is possible to conclude that the inflammatory state can negatively influence the bone turnover markers in obese adolescents. In addition, the interdisciplinary weight loss treatment improved the inflammatory state and body composition in obese adolescents. Therefore, the present findings should be considered in clinical practice.

摘要
目的：肥胖是一种多因素疾病，以促炎状态为特征，该状态与包括骨转换标志物（bone turnover marker）改变在内的多种合并症的发生发展密切相关。本研究旨在探讨接受为期1年跨学科减重治疗的肥胖青少年中，炎症状态对骨转换标志物的影响。
研究对象与方法：本研究纳入34名青春期后原发性肥胖青少年，其体质量指数（Body Mass Index, BMI）超过美国疾病控制与预防中心（Centers for Disease Control and Prevention, CDC）参考生长图表的95百分位。检测指标涵盖身体成分、骨转换标志物（bone turnover marker）、炎症生物标志物（inflammatory biomarker）以及内脏与皮下脂肪含量。所有受试者均接受为期1年的跨学科干预治疗，包括临床诊疗、体育锻炼、物理治疗、营养与心理咨询。
结果：研究观察到受试者体质量、体脂总量、内脏及皮下脂肪均显著降低，而身体瘦体重与骨矿物质含量则有所提升。炎症标志物水平得到改善：脂联素（adiponectin）、脂联素/瘦素（leptin）比值以及白细胞介素-15（interleukin-15）均呈升高趋势。此外，本研究证实脂联素/瘦素比值与骨钙素（osteocalcin）呈正相关关系；瘦体重与体脂量均为骨钙素的独立预测因子。同时还观察到瘦素与骨钙素、脂联素与β-胶原C端肽（Beta CTX-collagen）、内脏脂肪与脂联素之间存在显著负相关。
结论：本研究结果表明，炎症状态可对肥胖青少年的骨转换标志物产生负面影响。此外，跨学科减重治疗可有效改善肥胖青少年的炎症状态与身体成分。因此，本研究发现可为临床实践提供参考依据。