Can simple measures from clinical practice serve as a proxy for sarcopenic obesity and identify mortality risk?

Abstract

Sarcopenic obesity is a condition where loss of muscle mass occurs alongside fat gain, and it is considered a risk factor for mortality. However, the use of various definitions for this condition has led to conflicting results. To investigate whether the coexistence of low muscle mass and abdominal obesity, defined using two simple measures employed in clinical practice, is a risk factor for mortality in individuals aged 50 or older. A longitudinal study with a 14-year follow-up was conducted involving 5,440 participants of the English Longitudinal Study of Ageing. Abdominal obesity and low muscle mass were respectively defined based on high waist circumference and low skeletal muscle mass index (SMMI) determined by an equation. The sample was divided into four groups: non-low muscle mass/non-abdominal obesity (NLMM/NAO), non-low muscle mass/abdominal obesity (NLMM/AO), low muscle mass/non-abdominal obesity (LMM/NAO), and low muscle mass/abdominal obesity (LMM/AO). Cox regression models were used to estimate the mortality risk as a function of muscle mass and abdominal obesity status. LMM/AO increased the risk of death by 83% (HR:1.83; 95%CI: 1.35-2.66) compared to those in the NLMM/NAO group. AO alone was not associated with a greater risk of mortality (HR:1.09; 95%CI: 0.93-1.27), whereas LMM alone increased the risk by 40% (HR:1.40; 95%CI:1.18-1.66). Identifying LMM/AO in individuals aged 50 or older can be crucial for predicting the risk of mortality. Simple and easily applicable measures can serve as a proxy for sarcopenic obesity and aid in implementing the necessary interventions.