title: The Gly482Ser genotype at the PPARGC1A gene and elevated blood pressure: a meta-analysis involving 13,949 individuals.
abstract: The protein encoded by the PPARGC1A gene is expressed at high levels in metabolically active tissues and is involved in the control of oxidative stress via reactive oxygen species detoxification. Several recent reports suggest that the PPARGC1A Gly482Ser (rs8192678) missense polymorphism may relate inversely with blood pressure. We used conventional meta-analysis methods to assess the association between Gly482Ser and systolic (SBP) or diastolic blood pressures (DBP) or hypertension in 13,949 individuals from 17 studies, of which 6,042 were previously unpublished observations. The studies comprised cohorts of white European, Asian, and American Indian adults, and adolescents from South America. Stratified analyses were conducted to control for population stratification. Pooled genotype frequencies were 0.47 (Gly482Gly), 0.42 (Gly482Ser), and 0.11 (Ser482Ser). We found no evidence of association between Gly482Ser and SBP [Gly482Gly: mean = 131.0 mmHg, 95% confidence interval (CI) = 130.5-131.5 mmHg; Gly482Ser mean = 133.1 mmHg, 95% CI = 132.6-133.6 mmHg; Ser482Ser: mean = 133.5 mmHg, 95% CI = 132.5-134.5 mmHg; P = 0.409] or DBP (Gly482Gly: mean = 80.3 mmHg, 95% CI = 80.0-80.6 mmHg; Gly482Ser mean = 81.5 mmHg, 95% CI = 81.2-81.8 mmHg; Ser482Ser: mean = 82.1 mmHg, 95% CI = 81.5-82.7 mmHg; P = 0.651). Contrary to previous reports, we did not observe significant effect modification by sex (SBP, P = 0.966; DBP, P = 0.715). We were also unable to confirm the previously reported association between the Ser482 allele and hypertension [odds ratio: 0.97, 95% CI = 0.87-1.08, P = 0.585]. These results were materially unchanged when analyses were focused on whites only. However, statistical evidence of gene-age interaction was apparent for DBP [Gly482Gly: 73.5 (72.8, 74.2), Gly482Ser: 77.0 (76.2, 77.8), Ser482Ser: 79.1 (77.4, 80.9), P = 4.20 x 10(-12)] and SBP [Gly482Gly: 121.4 (120.4, 122.5), Gly482Ser: 125.9 (124.6, 127.1), Ser482Ser: 129.2 (126.5, 131.9), P = 7.20 x 10(-12)] in individuals <50 yr (n = 2,511); these genetic effects were absent in those older than 50 yr (n = 5,088) (SBP, P = 0.41; DBP, P = 0.51). Our findings suggest that the PPARGC1A Ser482 allele may be associated with higher blood pressure, but this is only apparent in younger adults.
authors.affiliation: Department of Public Health & Clinical Medicine, Umeå University Hospital, Umeå, Sweden.
authors.forename: Karani Santhanakrishnan
authors.initials: KS
authors.lastname: Vimaleswaran
authors.forename: Jian'an
authors.initials: J
authors.lastname: Luan
authors.forename: Gitte
authors.initials: G
authors.lastname: Andersen
authors.forename: Y Li
authors.initials: YL
authors.lastname: Muller
authors.forename: Eleanor
authors.initials: E
authors.lastname: Wheeler
authors.forename: Ema C
authors.initials: EC
authors.lastname: Brito
authors.forename: Stephen
authors.initials: S
authors.lastname: O'Rahilly
authors.forename: Oluf
authors.initials: O
authors.lastname: Pedersen
authors.forename: Leslie J
authors.initials: LJ
authors.lastname: Baier
authors.forename: William C
authors.initials: WC
authors.lastname: Knowler
authors.forename: Inês
authors.initials: I
authors.lastname: Barroso
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Wareham
authors.forename: Ruth J F
authors.initials: RJ
authors.lastname: Loos
authors.forename: Paul W
authors.initials: PW
authors.lastname: Franks
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001794:Blood Pressure / Q000235:genetics*; D015992:Body Mass Index; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D006360:Heat-Shock Proteins / Q000235:genetics*; D006801:Humans; D006973:Hypertension / Q000208:ethnology / Q000235:genetics* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D010641:Phenotype; D018570:Risk Assessment; D012307:Risk Factors; D012737:Sex Factors; D014157:Transcription Factors / Q000235:genetics*
chemical_list: D006360:Heat-Shock Proteins; C486497:PPARGC1A protein, human; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D014157:Transcription Factors