beta-Adrenoceptor-mediated thermogenesis and lipolysis in patients with chronic obstructive pulmonary disease.
The present study investigated whether development or maintenance of a relatively increased fat mass in normal-weight patients with chronic obstructive pulmonary disease (COPD), despite periods of weight loss, may be related to impaired beta-adrenoceptor-mediated responses in lipid utilization and thermogenesis. Nine COPD patients and nine healthy controls (body mass index: 23.0 +/- 1.3 vs. 23.8 +/- 0.6 kg/m2, not significant; fat mass: 19.0 +/- 2.1 vs. 11.9 +/- 1.5 kg, P < 0.01) received consecutive 30-min infusions of 6, 12, and 24 ng x kg fat free mass(-1) x min(-1) isoproterenol. During beta-adrenergic stimulation, nonesterified fatty acid levels increased significantly less in COPD patients (P < 0.001). Respiratory exchange ratio decreased similarly in both groups, indicating a similar change in the rate of lipid to carbohydrate oxidation. Energy expenditure increased similarly in both groups during beta-adrenergic stimulation. However, because plasma isoproterenol concentrations were significantly higher in COPD patients, thermogenesis related to isoproterenol concentration was significantly reduced in this group (P < 0.05). In conclusion, beta-adrenoceptor-mediated lipolysis and thermogenesis are impaired in COPD patients. This may play a role in the development or maintenance of their relatively increased fat mass.
Schiffelers
S L
SL
Department of Human Biology, Maastricht University, PO Box 616, NL-6200 MD Maastricht, The Netherlands. s.schiffelers@hb.unimaas.nl
Blaak
E E
EE
Baarends
E M
EM
Van Baak
M A
MA
Saris
W H
WH
Wouters
E F
EF
Schols
A M
AM
D000318:Adrenergic beta-Agonists / Q000097:blood / Q000494:pharmacology; D001833:Body Temperature Regulation / Q000502:physiology*; D004734:Energy Metabolism; D005230:Fatty Acids, Nonesterified / Q000097:blood; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007545:Isoproterenol / Q000097:blood / Q000494:pharmacology; D008066:Lipolysis / Q000502:physiology*; D008173:Lung Diseases, Obstructive / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine / Q000097:blood; D011659:Pulmonary Gas Exchange / Q000187:drug effects; D011943:Receptors, Adrenergic, beta / Q000502:physiology*; D012016:Reference Values
D000318:Adrenergic beta-Agonists; D005230:Fatty Acids, Nonesterified; D011943:Receptors, Adrenergic, beta; D007545:Isoproterenol; D009638:Norepinephrine