Muscle thermogenesis, measured by direct calorimetry on resting biopsy samples, was studied in 28 haemodialysis patients and related to thyroid function variables, plasma lipoprotein concentrations and post-heparin lipase activities. The heat production was decreased in about 40% of the patients and significantly correlated with total thyroxine and free thyroxine index. In addition to a slight to moderate hypercholesterolaemia comparable to that found in subclinical hypothyroidism, the patients had also hypertriglyceridaemia in combination with low lipoprotein lipase activity and impaired fat tolerance. The latter abnormalities were related to the lowered muscle heat production values. The pattern of changes may represent a biological adaptation to the systemic illness for conservation of energy.
Adult Aged