Effect of beta-hydroxy-beta-methylbutyrate, arginine, and lysine supplementation on strength, functionality, body composition, and protein metabolism in elderly women.

Objective: With advancing age, there is a gradual loss of muscle mass, strength, and functionality. The current studies were conducted to determine whether a mixture of specific nutrients, arginine and lysine, which support protein synthesis, and beta-hydroxy-beta-methylbutyrate (HMB), which can slow protein breakdown, could blunt the gradual loss of muscle that occurs in the elderly, thus improving strength and functionality.

Methods: In double-blind studies conducted at two separate sites, women (mean 76.

Bioelectrical impedance vs air displacement plethysmography and dual-energy X-ray absorptiometry to determine body composition in patients with end-stage renal disease.

Background: Patients with end-stage renal disease (ESRD) have significant shifts in fluid homeostasis that may impair measurements of body composition using methods based upon determinations of body water. Estimates of body water are fundamental for bioelectrical impedance analysis (BIA), which measures electrical resistance to estimate total body water and body composition.

Methods: BIA was compared with 2 other techniques: (1) air displacement plethysmography (ADP), which relies on measurements of body density to estimate body fat and fat-free masses; and (2) dual-energy x-ray absorptiometry (DXA), which depends on the relative attenuation of an x-ray beam to produce images of body fat and bone mineral.

Exercise augments the acute anabolic effects of intradialytic parenteral nutrition in chronic hemodialysis patients.

Decreased dietary protein intake and hemodialysis (HD)-associated protein catabolism are among several factors that predispose chronic hemodialysis (CHD) patients to uremic malnutrition and associated muscle wasting. Intradialytic parenteral nutrition (IDPN) acutely reverses the net negative whole body and forearm muscle protein balances observed during the HD procedure. Exercise has been shown to improve muscle protein homeostasis, especially if performed with adequately available intramuscular amino acids.

Inflammatory signals associated with hemodialysis.

Background: Inflammation is highly prevalent in chronic hemodialysis patients. Because hemodialysis involves the contact of blood with "foreign" surfaces, and the documented activation of several humoral and cellular pathways during the procedure, the hemodialysis procedure has been suggested as a potential source of inflammation in this patient population. Earlier studies did not provide clear-cut evidence of the potential contribution of the hemodialysis procedure to inflammation, as assessed by markers of inflammation such as cytokine levels and acute-phase protein production.

Intradialytic parenteral nutrition improves protein and energy homeostasis in chronic hemodialysis patients.

Decreased dietary protein intake and hemodialysis-associated protein catabolism are among several factors that predispose chronic hemodialysis (CHD) patients to protein calorie malnutrition. Since attempts to increase protein intake by dietary counseling are usually ineffective, intradialytic parenteral nutrition (IDPN) has been proposed as a potential therapeutic approach in malnourished CHD patients. In this study, we examined protein and energy homeostasis during hemodialysis in seven CHD patients at two separate hemodialysis sessions, with and without IDPN administration.