Association of age with muscle mass, fat mass and fat distribution in non-diabetic haemodialysis patients

Background. In the general population, aging induces changes in body composition, such as sarcopenia or a relative increase in visceral fat, but it remains unclear if similar changes occur in elderly haemodialysis (HD) patients. Methods. Age-related changes in muscle and fat mass and fat distribution in the thigh and abdomen were cross-sectionally investigated in Japanese HD patients. The thigh muscle area (TMA), thigh intermuscular fat area (IMFA), thigh subcutaneous fat area (TSFA), abdominal muscle area (AMA), abdominal visceral fat area (AVFA) and abdominal subcutaneous fat area (ASFA) were measured by computed tomography in 134 non-diabetic patients between 21 and 82 years on HD. AMA, AVFA and ASFA were also measured in 70 age-matched controls. Results. Muscle mass, fat mass and fat distribution differed significantly with age in both HD patients and controls, without significant differences in BMI. In both male and female HD patients, TMA and AMA showed significant negative correlations with age. All measures of subcutaneous fat—including TSFA, ASFA and the triceps skinfold thickness, were inversely associated with age in the female patients. In contrast, both IMFA and AVFA showed significant positive correlations with age in both male and female patients. The increase in the AVFA/ASFA ratio with age suggests progression of visceral fat accumulation in the elderly HD patients. Controls showed similar relationships between age and muscle mass and visceral fat accumulation. Conclusions. We found an association between age and decrease in muscle mass as well as increase in visceral and intermuscular fat in non-diabetic HD patients. Such changes may be associated with the metabolic abnormalities and increased mortality in elderly HD patients.