Document Detail


Oral amino acid supplements improve exercise capacities in elderly patients with chronic heart failure.
MedLine Citation:
PMID:  18514618     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
We investigated whether 30 days of oral supplementation with a special mixture of amino acids (AAs), together with conventional therapy, could improve exercise capacity in elderly outpatients with chronic heart failure (CHF). A group of 95 outpatients (12 women and 83 men; New York Heart Association class II-III) aged 65-74 years were studied. This was a randomized, double-blind, placebo-controlled study. The patients performed a basal exercise test and were then randomly assigned to a special oral nutritional mixture of AAs 4 g twice daily (n = 43) or placebo (n = 42). After 30 days we repeated the exercise test. In both tests we measured the following: oxygen consumption (VO2), CO2 production (VCO2), minute ventilation (VE), oxygen cost of ventilation (VO2/VE), CO2 elimination per liter of ventilation (VCO2/VE), respiratory exchange ratio (RER; calculated as VCO2/VO2), oxygen pulse (VO2/heart rate [HR]) and anaerobic metabolism during exercise (ANA-VO2). At day 30, exercise capacity in the AA group had improved (+11 +/- 8 W, p <0.01; +67.5 +/- 44 seconds, p <0.02). This improvement was associated with both reduced circulatory dysfunction and increased peripheral oxygen availability. Indeed, peak VO2 increased by 1.2 +/- 1.1 mL/kg per min (+12.7% +/- 13%; p<0.02) and VO2/HR improved by 1.5 +/- 1.4 mL O2 per heartbeat (p <0.05). ANA-VO2 was reduced by >50% in patients on AAs (from 20.2 +/- 10 mL/kg at day 0 to 10.9 +/- 5 mL/kg at day 30; p <0.02). These variables did not significantly change for patients who received placebo. In conclusion, the study showed that oral AA supplementation, in conjunction with standard pharmacologic therapy, appears to increase exercise capacity by improving circulatory function, muscle oxygen consumption, and aerobic production of energy in elderly outpatients with CHF.
Authors:
Roberto Aquilani; Simona Viglio; Paolo Iadarola; Cristina Opasich; Amidio Testa; Francesco S Dioguardi; Evasio Pasini
Related Documents :
8938578 - Direct and indirect assessment of skeletal muscle blood flow in patients with congestiv...
16540828 - Maximal accumulated oxygen deficit in patients with chronic heart failure.
947578 - Impaired forearm oxygen consumption during static exercise in patients with congestive ...
11283428 - Skeletal muscle oxidative capacity and exercise tolerance in rats with heart failure.
8254268 - Usefulness of anaerobic threshold for evaluating daily life activity and prescribing ex...
11669208 - The effects of changing atmospheric oxygen concentrations and background radiation leve...
Publication Detail:
Type:  Journal Article; Randomized Controlled Trial    
Journal Detail:
Title:  The American journal of cardiology     Volume:  101     ISSN:  0002-9149     ISO Abbreviation:  Am. J. Cardiol.     Publication Date:  2008 Jun 
Date Detail:
Created Date:  2008-06-02     Completed Date:  2008-07-24     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0207277     Medline TA:  Am J Cardiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  104E-110E     Citation Subset:  AIM; IM    
Affiliation:
Metabolic Service and Nutritional Pathophysiology, Foundation S. Maugeri, IRCCS, Scientific Institute of Montescano, Pavia, Italy. direzione.montescano@fsm.it
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Aged
Amino Acids / administration & dosage*
Blood Circulation / physiology
Dietary Supplements*
Double-Blind Method
Exercise Tolerance / drug effects*,  physiology
Female
Heart Failure / physiopathology*
Humans
Male
Muscle, Skeletal / metabolism
Oxygen Consumption / physiology
Chemical
Reg. No./Substance:
0/Amino Acids

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Incompleteness and harm avoidance in OCD symptom dimensions.
Next Document:  Hypercatabolic syndrome: molecular basis and effects of nutritional supplements with amino acids.