[Sugar substitutes or glucose in peripheral venous hypocaloric nutrition?]

Postoperative hypocaloric peripheral-venous nutrition with the same content of amino acids (1 g/kg BW/d) and carbohydrates (2 g/kg BW/d) was performed in two groups of patients, one group receiving xylitol and sorbitol (1:1), the other pure glucose only. Regarding the behavior of different parameters of the protein metabolism it could be demonstrated, that glucose supply although improving the N-retention by 12% had no significant favourable effect on viscerally synthesized plasma proteins in contrast to the polyols. Because of the nearly identical endogenous insulin stimulation in both groups it can be assumed, that glucose supply inhibits lipolysis completely thus reducing free fatty acids levels in plasma and therefore increasing peripheral insulin sensitivity resulting in enhanced utilisation of the amino acids supplied mainly in muscle. Additionally the improvement in synthesis of visceral proteins supplying polyols can be also due to a specific effect of these substrates, because the known activation of pentose-phosphate-cycle, especially by xylitol, increases RNA-synthesis and therefore lately improving protein synthesis, too.