Specific bioelectrical vectors pattern in individuals with sarcopenic obesity

Background: Sarcopenic obesity is a common condition in the elderly associated with excessive adiposity and low muscle mass and strength.Aims: This study aims to establish a method for detecting bioelectrical characteristics in individuals with sarcopenic obesity through specific Bioelectrical Impedance Vector Analysis (specific BIVA), while considering the characteristics of individuals with healthy, sarcopenic, and obese conditions.Methods: The sample was composed by 915 Italian adults over 50 years of age (men: 74.6 ± 8.8 y; women:76.3± 8.8 y) living in Sardinia (Italy).A dataset of 1590 US adults aged 21 e 49 years retrieved from the 2003 e 2004 National Health and Nutrition Examination Survey was also considered in a final step of the study.Anthropometric (stature, weight, waist, arm, and calf circumferences) and whole-body bioelectrical variables were taken.In the Italian sample, bioelectrical impedance was applied to estimate the relative content of fat mass and skeletal muscle mass.Groups with healthy body composition (NS-NO), or consistent with sarcopenia (S), sarcopenic obesity (S-O), and obesity (O) were defined based on the cut-offs suggested by European expert guidelines (EWGSOP2 and ESPEN-EASO).Specific BIVA was applied to compare groups and to identify the area for sarcopenic obesity within young-adults tolerance ellipses.The position of the specific vector of US individuals with S-O, selected on the basis of DXA measurements, was also considered.Results: In both sexes of the Italian sample, the bioelectrical characteristics of the four groups were different (p < 0.001).The differences were mainly related to vector length, indicative of higher fat mass, which was longer in the O and S-O groups, and phase angle, a proxy of intracellular/extracellular water and muscle mass, lower in the sarcopenic groups.Bioelectrical vectors of the S-O group fell in the right quadrant, outside of the 95 % tolerance ellipses of young adults.The mean vector of the US sample with S-O fell in the same area.Within the S-O area, women had similar bioelectrical values, while men showed phase angle variability, which was related to the severity of the condition.Conclusions: Specific BIVA detects body composition peculiarities of individuals with sarcopenic obesity, thus allowing their diagnosis when associated with low handgrip strength values.