Body composition in sarcopenic obesity: systematic review of the literature

Although, recently a mounting interest in the literature has been directed to sarcopenic obesity, currently, different definitions of sarcopenic obesity (SO) exist and diagnostic criteria are not universally established. The aim of the present systematic review is to summarize the state of the art according to extant literature about this topic. A systematic review of the literature was performed considering the revision question: "sarcopenic obesity: body composition''. Analysis and presentation of the outcomes were carried out in the form of a narrative resume ' of the reports. Twenty-six studies were considered eligible for the systematic review involving globally more than 23,000 subjects. In all the studies examined, except one, the definition of sarcopenic obesity was based on the co-presence of obesity and sarcopenia. With respect to obesity, different parameters (body mass index, fat mass and visceral fat area) were used (as single parameters or in association to the other adiposity measures). For sarcopenia, the appendicular skeletal muscle mass standardized for height or weight, cross-sectional area at the quadriceps level, muscle strength and/or muscle/fat-free mass indexes were considered. Body composition analysis was performed, depending on the studies, through DXA scan, CT scan bioimpedance analysis, dynamometer test or anthropometric parameters. To date, just few papers provided clear and shared diagnostic criteria of SO. In fact, in our review, criteria adopted by single authors were only partially overlapping. One of the main obstacles is represented by the definition of SO, and especially whether it should be based only on criteria of body composition or also functional criteria should be taken into account.