RESUMO
BACKGROUND: Blood pressure (BP) homeostasis involves complex interactions among genetic and nongenetic factors, providing major challenges to dissection of the genetic components that influence BP and hypertension. In this study, we examine the effects of interaction of genetic variants with physical activity on BP in a relatively genetically homogenous cohort of rural Chinese villagers. METHODS: Generalized estimating equations analysis was used to test for associations of systolic blood pressure (SBP) and diastolic blood pressure (DBP) with variants in 24 genes in BP pathways (196 single-nucleotide polymorphisms (SNPs)) among 3,142 Chinese participants divided according to physical activity (active vs. inactive groups). RESULTS: In the physically active group, two SNPs in NR3C2 were significantly associated with lower SBP, and a SNP in SCNN1B was significantly associated with lower SBP and DBP. In the physically inactive group, a SNP in APLNR was associated with lower SBP, a SNP in GNB3 (guanine nucleotide binding protein, ß polypeptide 3) was associated with higher SBP and DBP, and a SNP in BDKRB2 (bradykinin receptor B2) was associated with lower DBP. Cumulative effects in carriers of minor alleles of these SNPs showed reductions of SBP and DBP as large as 8 and 5 mm Hg, respectively, in the active individuals compared to inactive individuals carrying the same number of minor alleles. CONCLUSIONS: We found that physical activity modifies the effects of genetic variants on BP. However, our results also show that active individuals with specific genotypes always have lower BP than inactive individuals with the same genotypes, demonstrating the overall beneficial effects of physical activity on BP.
Assuntos
Pressão Sanguínea/genética , Canais Epiteliais de Sódio/genética , Hipertensão/genética , Atividade Motora/genética , Receptores de Mineralocorticoides/genética , Adolescente , Adulto , Idoso , Receptores de Apelina , Povo Asiático/genética , Estudos de Coortes , Feminino , Proteínas Heterotriméricas de Ligação ao GTP/genética , Humanos , Masculino , Pessoa de Meia-Idade , Atividade Motora/fisiologia , Polimorfismo de Nucleotídeo Único , Receptor B2 da Bradicinina/genética , Receptores Acoplados a Proteínas G/genética , População RuralRESUMO
OBJECTIVE: Although beneficial effects of potassium intake on blood pressure (BP) are well established, little is known about genetic factors that underlie interindividual variability in BP response to dietary potassium. In a previous study, we reported the first evidence for significant heritabilities for BP response in a dietary intervention study in rural Chinese. In this report, we extend our genetic studies to examine associations with polymorphisms in genes in vascular endothelial pathways. METHODS: We genotyped study participants for 23 single nucleotide polymorphisms (SNPs) in endothelin 1 (EDN1), nitric oxide synthase 3, and E selectin (SELE). We tested 17 of these SNPs for associations with BP response to potassium supplementation in 1843 participants. Association tests used population-based [generalized estimation equation (GEE)] and family-based (quantitative transmission disequilibrium test) methods, as well as tests for gene-by-gene (GxG) interaction (generalized multifactor dimensionalilty reduction and GEE). RESULTS: Single SNP analysis identified significant associations for several SNPs in EDN1 with multiple measures of BP response to potassium supplementation. The cumulative effects of the minor EDN1 alleles that showed significant associations were to reduce measures of BP response by 0.5-0.9 mmHg. We found significant evidence for effects of GxG interactions between EDN1 and SELE, even in the absence of individual associations with SELE variants. CONCLUSION: Our results implicate variability in EDN1 and SELE as genetic factors that influence BP response to potassium intake. Although such epidemiological studies do not allow direct determination of physiologic mechanisms, our findings of joint effects identify EDN1 and SELE as targets for functional studies to determine their interactions in BP response to potassium intake.
Assuntos
Pressão Sanguínea/genética , Endotelina-1/genética , Variação Genética , Potássio na Dieta/farmacologia , População Rural/estatística & dados numéricos , Adulto , Alelos , Povo Asiático , Pressão Sanguínea/fisiologia , China , Selectina E/genética , Estudos Epidemiológicos , Feminino , Genótipo , Humanos , Masculino , Óxido Nítrico Sintase Tipo III/genética , Polimorfismo de Nucleotídeo Único , Potássio na Dieta/administração & dosagemRESUMO
OBJECTIVES: Determining physical activity levels in the community provides a context for the development and implementation of programs aimed at increasing these activity levels. Therefore, we assessed overall, work-related, and leisure-time physical activity in a representative sample of Chinese adults, aged 35 to 74 years, using data from the International Collaborative Study of Cardiovascular Disease in Asia. METHODS: Being physically active was defined as participating in 30 or more minutes of moderate or vigorous activity daily. Work-related and leisure-time physical activities were defined as being physically active and participating in any moderate or vigorous activity at work or during leisure time, respectively. RESULTS: In rural and urban China, 78.1% and 21.8% of residents, respectively, were physically active; 75.8% and 16.5%, respectively, participated in work-related activity; and 28.9% and 7.9%, respectively, participated in leisure-time physical activity. In both rural and urban settings, younger adults, men, and southern residents were more likely to be physically active and to participate in work-related and leisure-time physical activity than older adults, women, and northern residents. CONCLUSIONS: Intervention strategies to promote leisure-time physical activity, especially among urban residents, should be considered a major health priority in China.
