Early enteral nutrition with whey protein or casein in elderly patients with acute ischemic stroke: a double-blind randomized trial

Abstract

Objective: The aim of this study was to investigate the effects of an early enteral formula containing whey protein, in comparison to a standard enteral formula containing casein as the protein source, on the levels of glutathione and inflammatory markers in aged patients with acute ischemic stroke.

Methods: Thirty-one elderly patients (12 males and 19 females; median age = 74 [range,65-90] y old) with ischemic stroke were randomized to receive early nasogastric feeding (35 kcal/kg/d and 1.2 g of protein/kg/d) with either a formula containing polymeric [corrected] casein (casein group, n =16) or another isocaloric and isonitrogenous formula containing hydrolyzed whey protein (WP group, n = 15) for 5 d. The primary endpoints of the study were the changes in the serum levels of glutathione peroxidase, C-reactive protein (CRP), and interleukin 6 (IL-6).

Results: Twenty-five patients completed the study (10 in the WP group and 15 in the casein group). Mortality was similar between groups (33%; P = 1.00) and was associated with higher serum IL-6 (73.7 ± 24.7 versus 16.6 ± 2.4 pg/dL; P = 0.04) and CRP (82.0 ± 35.6 versus 48.3 ± 14.5 mg/L; P = 0.02) levels. Albumin levels dropped from the first to the fifth feeding day only in the casein group (P < 0.01). Serum IL-6 decreased (62.7 ± 47.2 to 20.6 ± 10.3 pg/dL; P = 0.02) and glutathione increased (32.2 ± 2.1 to 39.9 ± 6.8 U/G Hb; P = 0.03) only in the WP group. Serum IL-6 was lower (P = 0.03) and glutathione was higher (P = 0.03) in whey protein-fed patients than in the casein group.

Conclusion: Enteral formula containing whey protein may decrease inflammation and increase antioxidant defenses in elderly patients with ischemic stroke, compared to casein-containing formula.