Do different obesity-criteria result in different phenotypes in older people?

Abstract

Rationale: Sarcopenic obesity is a public health concern but identification of obesity in older age is challenging.1 The aim of this study was to identify and compare obesity phenotypes using two different criteria.

Methods: In a sample of Scottish community dwellers aged ≥65 y, body composition (assessed using dual Bioelectrical Impedance Analysis) and strength (measured using handgrip dynamometry) were compared, defining obesity as (a) Body Mass Index (BMI) >30 kg*m−2 or (b) %body fat (%BF) >28% (m) and >40% (f ).2 A Mann-Whitney test was used to detect differences in obese vs non-obese phenotypes.

Results: 108 participants, median (IQR) age 70 (67, 75)y, were screened. Based on BMI classification, obese adults had a significantly higher skeletal muscle mass (SMM) than the non-obese, however strength was not different between the groups (Table 1). Based on %BF the opposite pattern was observed; the non-obese adults had higher SMM and were also stronger than the obese. %BF identified more cases of obesity

Conclusion: Classification of the older obese phenotype is dependent upon method of assessment. A consensus for the definition criteria of obesity in older age is crucial in order to identify obesity and sarcopenic obesity.