Sarcopenic obesity and amino acids: Concord Health and Ageing in Men Project.

Although characteristic changes in amino acid concentrations occur in obesity and sarcopenia, amino acids concentrations have not been reported in sarcopenic obesity. We studied n=831 men aged 75 years and older from the five-year follow-up of the Concord Health and Ageing in Men Project (CHAMP). Sarcopenia was defined using the Foundation of the National Institutes of Health (FNIH) criteria and obesity was defined as >30% fat mass. There were 31 men (3.7%) who had sarcopenic obesity. Branched chain amino acids were elevated in the obese (but not sarcopenic) group (n=348) but reduced in both the sarcopenic (but not obese) (n=44) and the sarcopenic obese groups. Apart from this, most of the amino acid concentrations were between those for the obese and the sarcopenic groups. Yet despite low concentrations of branched chain amino acids, the sarcopenic obese group had indications of insulin resistance and diabetes mellitus (fasting glucose and insulin concentrations, homeostatic model assessment (HOMA-IR) and percentage of participants taking diabetes medications) that were similar to the obese group. In summary, sarcopenic obese subjects did not have a unique amino acid signature. In obesity, elevated branched chain amino acids are not a prerequisite for insulin resistance and diabetes if obesity is associated with sarcopenia.