Impact of Sarcopenia on the Prognosis in Heart Failure

Chronic heart failure (CHF) is an important health issue with high mortality. CHF occurs in 10% or more in the elderly population in developed countries. Since the pathophysiology of CHF involves detrimental levels of catabolism, over 60% of patients with CHF are reported to have muscle weakness and fatigue caused by muscle atrophy. Although obese patients with CHF reportedly have better prognoses compared with lean patients, “obesity paradox” is not observed in case of having insulin resistance. Anker et al reported that prevalence of cardiac cachexia based on body weight loss increases with advancing CHF and is associated with poor prognosis. However, body weight is affected by fluid status. Sarcopenia is defined as skeletal muscle loss and dysfunction during aging and affliction with a chronic disease. Therefore, we evaluated sarcopenia using fat-free mass index (FFMI), which reflects the masses of skeletal muscle, organs, bone, and connective tissue and which is an indicator of resting energy expenditure. Although FFMI is usually measured by bioelectrical impedance analysis or dual-energy X-ray absorptiometry, we estimated FFMI according to the Forbes formula, which simply uses urinary creatinine. Prevalence of sarcopenia was 25% in patients with CHF. Sarcopenia was an independent prognostic factor in patients with CHF. Future research is needed to assess whether therapeutic intervention to ameliorate sarcopenia can improve cardiac prognosis.