Cachexie bij kanker: stoornissen in de eiwit- en aminozuurstofwisseling

- Cancer-induced cachexia is characterized by complex changes in the intermediary metabolism. There is a raised basal metabolism with increased turnover of lipids, carbohydrates and proteins.

- In this altered metabolic milieu, protein catabolism occurs in peripheral tissue resulting in release of amino acids for the benefit of visceral organs. These as a rule increase in protein mass and also produce more plasma proteins.

- The amino acid glutamine plays a central part in this. It is released in large amounts from muscle tissue and is consumed to a high degree by visceral organs and immune cells.

- Although biochemically glutamine is not an essential amino acid, in cancer-induced cachexia it appears to be a ‘conditionally’ essential amino acid.

- Changes in the protein metabolism appear to be controlled by chronically increased neuroendocrine and inflammatory activity (exerted among other things by tumour necrosis factor α, interleukins 1 and 6 and catecholamines).

- Fundamental research, animal experiments and certain clinical trials show that the metabolism altered by these mediators can be corrected using hormonal preparations such as growth hormone, β₂-adrenergic agonists and insulin.

- In the future it may conceivably be possible to correct the metabolic disturbance with drugs and the depletion of nutrients with specific nutritional supplements.