Long-term exercise training decreases interleukin-6 (IL-6) serum levels in subjects with impaired glucose tolerance: effect of the -174G/C variant in IL-6 gene.
OBJECTIVE
Exercise training has been shown to have anti-inflammatory effects in patients with type 2 diabetes. Changes in interleukin-6 (IL-6) serum concentrations in response to training could contribute to these beneficial effects. However, there are heterogeneous data on whether circulating IL-6 is altered by exercise training. We therefore hypothesize that genetic factors modify the individual changes in IL-6 levels after long-term training.


METHODS
The -174G/C variant in the IL-6 gene was genotyped in 60 subjects with impaired glucose tolerance. For a 12-month interventional study, patients were randomized into three groups: a control group (n=16) was compared with one group, which underwent a standardized training program (n=24) and another group, which was treated with 4 mg rosiglitazone once daily (n=20). At baseline, after 1, 6, and 12 months, we measured anthropometric parameters and serum concentration of IL-6 and, at baseline and after 12 months, we determined glucose tolerance and fitness level.


RESULTS
Only in subjects carrying the SNP -174C allele did long-term exercise training result in significantly reduced IL-6 serum concentrations. Multivariate linear regression analysis identified the IL-6 genotype as a significant predictor of changes in IL-6 serum concentrations independent of age, gender and improvement in body mass index, hemoglobin (Hb)A(1c), and fitness level in response to training.


CONCLUSIONS
Genetic variants in the IL-6 gene significantly modify changes in IL-6 serum concentrations in response to long-term exercise training programs. Our data suggest that genetic factors are important determinants for the individual response to anti-inflammatory effects of exercise training.
Oberbach
Andreas
A
Department of Medicine, Faculty of Medicine, University of Leipzig, Philipp-Rosenthal-Str. 27, D-04103 Leipzig, Germany.
Lehmann
Stefanie
S
Kirsch
Katharina
K
Krist
Joanna
J
Sonnabend
Melanie
M
Linke
Axel
A
Tönjes
Anke
A
Stumvoll
Michael
M
Blüher
Matthias
M
Kovacs
Peter
P
D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000188:drug therapy / Q000235:genetics; D015536:Down-Regulation / Q000235:genetics; D015444:Exercise / Q000502:physiology*; D005260:Female; D005838:Genotype; D018149:Glucose Intolerance / Q000097:blood* / Q000235:genetics; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use; D015850:Interleukin-6 / Q000097:blood* / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D010807:Physical Endurance / Q000502:physiology; D020641:Polymorphism, Single Nucleotide / Q000502:physiology; D000077154:Rosiglitazone; D045162:Thiazolidinediones / Q000627:therapeutic use; D013997:Time Factors
D007004:Hypoglycemic Agents; D015850:Interleukin-6; D045162:Thiazolidinediones; D000077154:Rosiglitazone