Endurance training and GH administration in elderly women: effects on abdominal adipose tissue lipolysis.
In the present study, the effect of endurance training alone and endurance training combined with recombinant human growth hormone (rhGH) administration on subcutaneous abdominal adipose tissue lipolysis was investigated. Sixteen healthy women [age 75 +/- 2 yr (mean +/- SE)] underwent a 12-wk endurance training program on a cycle ergometer. rhGH was administered in a randomized, double-blinded, placebo-controlled design in addition to the training program. Subcutaneous abdominal adipose tissue lipolysis was estimated by means of microdialysis combined with measurements of subcutaneous abdominal adipose tissue blood flow (ATBF; (133)Xe washout). Whole body fat oxidation was estimated simultaneously by indirect calorimetry. Before and after completion of the training program, measurements were performed both at rest and during 60 min of continuous cycling at a workload corresponding to 60% of pretraining peak oxygen uptake. Endurance training alone did not affect subcutaneous abdominal adipose tissue lipolysis either at rest or during exercise, as reflected by identical levels of interstitial adipose tissue glycerol, subcutaneous abdominal ATBF, and plasma nonesterified fatty acids before and after completion of the training program. Similarly, no effect on subcutaneous abdominal adipose tissue lipolysis was observed when combining endurance training with rhGH administration. However, in both the placebo and the GH groups, fat oxidation was significantly increased during exercise performed at the same absolute workload after completion of the training program. We conclude that the changed lipid metabolism during exercise observed after endurance training alone or after endurance training combined with rhGH administration is not due to alterations in subcutaneous abdominal adipose tissue metabolism in elderly women.
Lange
K H
KH
Sports Medicine Research Unit, Bispebjerg Hospital, DK-2400 Copenhagen NV, Denmark. klange@dadlnet.dk
Lorentsen
J
J
Isaksson
F
F
Juul
A
A
Rasmussen
M H
MH
Christensen
N J
NJ
Bülow
J
J
Kjaer
M
M
D000005:Abdomen; D000273:Adipose Tissue / Q000098:blood supply / Q000378:metabolism*; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers; D001786:Blood Glucose; D001823:Body Composition; D002153:Calorimetry, Indirect; D004837:Epinephrine / Q000097:blood; D005080:Exercise Test; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005260:Female; D005990:Glycerol / Q000097:blood; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D006400:Hematocrit; D019382:Human Growth Hormone / Q000008:administration & dosage* / Q000097:blood; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D007335:Insulin-Like Growth Factor II / Q000378:metabolism; D019344:Lactic Acid / Q000097:blood; D008066:Lipolysis / Q000187:drug effects* / Q000502:physiology; D017551:Microdialysis; D009638:Norepinephrine; D010101:Oxygen Consumption / Q000187:drug effects / Q000502:physiology; D010807:Physical Endurance / Q000187:drug effects* / Q000502:physiology*; D012039:Regional Blood Flow / Q000187:drug effects / Q000502:physiology
D015415:Biomarkers; D001786:Blood Glucose; D005230:Fatty Acids, Nonesterified; D018972:Insulin-Like Growth Factor Binding Protein 3; D019382:Human Growth Hormone; D019344:Lactic Acid; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II; D005990:Glycerol; D009638:Norepinephrine; D004837:Epinephrine