C-reactive protein genotype affects exercise training-induced changes in insulin sensitivity.
An etiologic role for chronic inflammation in the development of insulin resistance has been hypothesized. We determined whether the -732A/G and +219G/A C-reactive protein (CRP) gene variants affect insulin and glucose measures and whether these variants affect training-related changes in insulin sensitivity and glucose measures. Men and women 50 to 75 years old (n = 61) underwent baseline testing that included glucose tolerance, maximal oxygen consumption, body composition, CRP levels, and genotyping assessments. Tests were repeated after 24 weeks of aerobic exercise training. In bivariate analyses, CRP -732A/G G allele carriers had significantly lower baseline postprandial plasma glucose and after-training CRP levels. After exercise training, the -732A/G G allele carriers had approximately 28% increase in insulin sensitivity index (ISI) and approximately 26% reduction in insulin area under the curve (AUC), compared with the approximately 7% increase in ISI and approximately 15% reduction in insulin AUC in the A allele homozygotes (P = .03). The significant enhancement of ISI in -732A/G G allele carriers remained evident in analyses limited to those with normal glucose tolerance. Multivariate analyses adjusted for demographic and biologic variables confirmed the significant enhancement of training-induced improvement in ISI by the CRP gene variant. In addition, the CRP -732A/G and +219G/A haplotype significantly associated with training-induced improvements in ISI and insulin AUC in separate multivariate models. In conclusion, the CRP -732A/G variant modulates exercise training-related improvements in ISI and glucose AUC, and the haplotype of the CRP -732A/G and +219G/A variants significantly affected training-induced changes in ISI and insulin AUC.
Department of Kinesiology, University of Maryland, College Park, MD 20742, USA. tobisesan@howard.edu
Thomas O
TO
Obisesan
Christiaan
C
Leeuwenburgh
Robert E
RE
Ferrell
Dana A
DA
Phares
Jennifer A
JA
McKenzie
Steven J
SJ
Prior
James M
JM
Hagberg
D000368:Aged; D019540:Area Under Curve; D001786:Blood Glucose / Q000032:analysis; D002097:C-Reactive Protein / Q000235:genetics* / Q000378:metabolism; D005260:Female; D005787:Gene Frequency; D014644:Genetic Variation; D005838:Genotype; D006239:Haplotypes; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010806:Physical Education and Training
D001786:Blood Glucose; D007328:Insulin; D002097:C-Reactive Protein