Nature Publishing Group, publisher of Nature, and other science journals and reference works NATURE.COM NATURE NEWS NATUREJOBS NATUREEVENTS ABOUT NPG
Help Nature.com site index  
International Journal of Obesity
SEARCH     advanced search my account e-alerts subscribe register
Journal home
Advance online publication
Current issue
Archive
Press releases
For authors
For referees
Contact editorial office
About the journal
For librarians
Subscribe
Advertising
naturereprints
Contact NPG
Customer services
Site features
NPG Subject areas
Access material from all our publications in your subject area:
Biotechnology Biotechnology
Cancer Cancer
Chemistry Chemistry
Dentistry Dentistry
Development Development
Drug Discovery Drug Discovery
Earth Sciences Earth Sciences
Evolution & Ecology Evolution & Ecology
Genetics Genetics
Immunology Immunology
Materials Materials Science
Medical Research Medical Research
Microbiology Microbiology
Molecular Cell Biology Molecular Cell Biology
Neuroscience Neuroscience
Pharmacology Pharmacology
Physics Physics
Browse all publications
 
April 1999, Volume 23, Number 4, Pages 411-418
Table of contents    Previous  Abstract  Next   Article  PDF
Paper
Substrate utilization and thermogenic responses to bold beta-adrenergic stimulation in obese subjects with NIDDM
E E Blaak1, W H M Saris1 and B H R Wolffenbuttel2

1Department of Human Biology, Maastricht University, Maastricht, The Netherlands

2Department of Endocrinology, University Hospital Maastricht, Maastricht, The Netherlands

Correspondence to: Dr E E Blaak, Dept of Human Biology, Nutrition Research Centre, Maastricht University, PO Box 616, 6200 MD Maastricht, The Netherlands

Abstract

OBJECTIVE: This study intended to investigate disturbances in beta-adrenergically-mediated substrate utilization and thermogenesis in obese subjects with mild non insulin-dependent diabetes mellitus (NIDDM).

DESIGN: Following a baseline period of 30 min, the beta-agonist isoproterenol (ISO) was administered in increasing doses of 6, 12, and 24 ng/kgFFM.min, each dose for 30 min.

SUBJECTS: Nine healthy lean males (CON, 50.6±2.4 y, % body fat: 16.0±1.8) and 10 obese subjects with NIDDM (51.8±2.4 y, % body fat 34.1±1.9).

RESULTS: Basal non esterified fatty acid concentrations (NEFA) and basal fat oxidation (absolute or expressed per unit fat free mass, FFM) were significantly higher in NIDDM as compared to CON, whereas basal carbohydrate (CHO) oxidation was significantly lower. The ISO-induced increase in NEFA-concentrations was blunted in NIDDM (Delta at 24 ng/kgFFM.min: CON: 717±59 mumol/l vs NIDDM: 358±97 mumol/l, P<0.01). The non-protein respiratory exchange ratio (RER) did not change in NIDDM and significantly decreased in CON during ISO-infusion (P<0.05), reflecting the tendency towards a blunted increase in fat oxidation in NIDDM (Delta fat ox at 24 ng; CON: 0.025±0.005 g/min vs NIDDM 0.016±0.007 g/min). The ISO-induced thermogenic response was comparable in NIDDM and CON (at 24 ng %increase above baseline: CON: 16.8±2.2% vs NIDDM: 14.7±0.9%). At all time points, there were no significant differences in circulating ISO and noradrenaline concentrations. Basal adrenaline (A) concentrations and A concentrations during ISO-infusion were significantly lower in NIDDM (basal A; CON: 64±15 pg/ml vs NIDDM: 25±2 pg/ml, P<0.001).

CONCLUSION: There appear to be deviations in beta-adrenoceptor mediated fat utilization and adrenal medulla function in obesity-associated NIDDM. The impairments in sympathetically mediated fat utilization have previously been observed in 'simple' obese subjects, indicating that these disturbances are confined to the obese state per se.

Keywords

beta-adrenergic stimulation; NIDDM; obesity; fat metabolism; thermogenesis; sympathetic nervous system

Received 6 July 1998; revised 20 November 1998; accepted 2 December 1998
April 1999, Volume 23, Number 4, Pages 411-418
Table of contents    Previous  Abstract  Next   Article  PDF
Privacy Policy © 1999 Nature Publishing Group