Effects of beta‐hydroxy‐beta‐methylbutyrate supplementation on skeletal muscle in healthy and cirrhotic rats

Abstract

Summary Beta‐hydroxy‐beta‐methylbutyrate (HMB) is a leucine metabolite with protein anabolic effects. We examined the effects of an HMB‐enriched diet in healthy rats and rats with liver cirrhosis induced by multiple doses of carbon tetrachloride (CCl4). HMB increased branched‐chain amino acids (BCAAs; valine, leucine and isoleucine) in blood and BCAA and ATP in muscles of healthy animals. The effect on muscle mass and protein content was insignificant. In CCl4‐treated animals alterations characteristic of liver cirrhosis were found with decreased ratio of the BCAA to aromatic amino acids in blood and lower muscle mass and ATP content when compared with controls. In CCl4‐treated animals consuming HMB, we observed higher mortality, lower body weight, higher BCAA levels in blood plasma, higher ATP content in muscles, and lower ATP content and higher cathepsin B and L activities in the liver when compared with CCl4‐treated animals without HMB. We conclude that (1) HMB supplementation has a positive effect on muscle mitochondrial function and enhances BCAA concentrations in healthy animals and (2) the effects of HMB on the course of liver cirrhosis in CCl4‐treated rats are detrimental. Further studies examining the effects of HMB in other models of hepatic injury are needed to determine pros and cons of HMB in the treatment of subjects with liver cirrhosis.

Amino Acid Profile in Malnourished Patients with Liver Cirrhosis and Its Modification with Oral Nutritional Supplements: Implications on Minimal Hepatic Encephalopathy

“…Recent studies have shown that 12-week HMB supplementation improved muscle performance in compensated cirrhotic patients [25] and increased plasma BCAA in cirrhotic and partially hepatectomized rats [26,27]. However, the effect of oral nutritional supplements (ONS) with HMB on the amino acid profile of patients with decompensated cirrhosis has not been studied.…”

Attenuating Muscle Mass Loss in Critical Illness: the Role of Nutrition and Exercise

“…Skeletal muscle is highly responsive to external stimuli such as nutrition and physical activity interventions [7]. In health, a number of nutritional strategies have been shown effective in stimulating muscle protein synthesis, including essential amino acids or their metabolites (such as leucine and HMB) [18] and higher protein doses [19]. Physical activity and dietary intake are modifiable factors associated with the risk of chronic morbidity and mortality in the general population and can positively impact on muscle mass [20,21].…”