n‐3 fatty acids are reduced in advanced cancer patients with sarcopenia

Little is known about the essential fatty acid status of cancer patients at diagnosis and throughout treatment. Sarcopenia (depletion of skeletal muscle) is associated with physical disability and mortality in aging and chronic diseases but the relationship between body composition and nutritional status in cancer is unclear. The objective of this study was to measure n‐3 and n‐6 fatty acids in plasma phospholipids of advanced non‐small cell lung cancer patients. Total skeletal muscle cross‐sectional area (n=22) was evaluated using lumbar CT images. Cut‐points [?: <55.4 cm 2 /m 2 ; ?: <38.9cm 2 /m 2 ; Mourtzakis et al Appl Physiol Nutr Metabol 2008] were used to classify subjects as sarcopenic (n=13) or non‐sarcopenic (n=9). Phospholipids were isolated from plasma lipids using thin layer chromatography. Amounts and types of fatty acids were determined using gas liquid chromatography. Total n‐3 fatty acids of sarcopenic subjects were lower than non‐sarcopenic subjects (16±11µg/mL versus 35±10 µg/mL, p =0.001), with 45% lower 20:5n‐3(p=0.005) and 54% lower 22:6n‐3 (p=0.0098). This resulted in a two‐fold higher n6:n3 ratio (p=0.05) in the sarcopenic versus non‐sarcopenic subjects. Cancer patients with sarcopenia have pronounced alterations in lipid metabolism, specifically n‐3 fatty acids, suggesting an important relationship between muscle atrophy and essential fatty acid metabolism. (Supported by CIHR). Grant Funding Source Canadian Institute for Health Research