Frailty is associated with myosteatosis in obese patients with colorectal cancer

Summary Background & aims We aimed to explore the determinants of muscle fat infiltration and to investigate whether myosteatosis, assessed as muscle fat infiltration percentage (%MFI) and muscle attenuation from computed tomography (CT), is associated with frailty in a group of patients with colorectal cancer (CRC). Methods Cross sectional study including CRC patients. CT scan of the third lumbar vertebra was used to quantify body composition and the degree of %MFI (reported as percentage of fat within muscle area). Frailty was defined by Fried et al. (2001) as the presence of more than 3 criteria: unintentional weight loss, self-reported exhaustion, weakness (low handgrip strength), slow walking speed (gait speed) and low physical activity. Obesity was defined according to sex-and-age-specific body fat percentage (%BF) cutoff. Results A sample of 184 patients (age 60 ± 11 years; 58% men; 29% of patients with frailty) was studied. The sample was divided according to tertiles of MFI% (1st tertile 0 to 2.89%, n = 60; 2nd tertile ≥ 3.9–8.19%, n = 64; 3rd tertile ≥ 8.2–26%, n = 60). Age, females, body mass index, %BF, subcutaneous and visceral adipose tissue and the proportion of patients with frailty were significantly higher in the 3rd %MFI tertile. Phase angle and muscle attenuation were significantly lower in the 3rd %MFI tertile. The determinants of %MFI (r 2  = 0.49), which was log transformed due to its normal distribution, were %BF (β = 0.54; e β  = 1.72; 95% CI: 0.032 to 0.051; P β  = 1.40; 95% CI: 0.016 to 0.032; P β  = 0.87; 95% CI: −0.84 to −0.001; P  = 0.049). In addition, in obese patients (n = 74) presenting 4 or 5 frailty criteria increased the chance of having higher %MFI and lower muscle attenuation, after adjustment for sex, age and comorbidities when compared to none or 1 criteria. Conclusions In a sample of CRC patients, %BF and gait speed were the determinants of %MFI. In addition, markers of myostetatosis were associated with frailty in the obese patients.