Plasma levels of transthyretin and retinol-binding protein in child-A cirrhotic patients in relation to protein-calorie status and plasma amino acids, zinc, vitamin A and plasma thyroid hormones

RESUMO

Transthyretin and retinol-binding protein are sensitive markers of acute protein-calorie malnutrition both for early diagnosis and dietary evaluation. A preliminary study showed that retinol-binding protein is the most sensitive marker of protein-calorie malnutrition in cirrhotic patients, even those with the mild form of the disease (Child A). However, in addition to being affected by protein-calorie malnutrition, the levels of these short half-life-liver-produced proteins are also influenced by other factors of a nutritional (zinc, tryptophan, vitamin A, etc) and non-nutritional (Sex, aging, hormones, renal and liver functions and inflammatory activity) nature. These interactions were investigated in 11 adult male patients (49.9 + 9.2 years of age) with alcoholic cirrhosis (Child-Pugh grade A) and with normal renal function. Both transthyretin and retinol binding protein were reduced below normal levels in 55 percent of the patients, in close agreement with their plasma levels of retinol. In 67 percent of the patients (4/6), the reduced levels of transthyretin and retinol-binding protein were caused by altered liver function and in 50 percent (3/6) they were caused by protein-calorie malnutrition. Thus, the present data, taken as a whole, indicate that reduced transthyretin and retinol-binding protein levels in mild cirrhosis of the liver are mainly due to liver failure and/or vitamin A status rather than representating an isolated protein-calorie malnutrition indicator.