Environmental And Genetic Determinants Of Hyperhomocysteinemia In Chinese Hypertensives

Background: Hyperhomocysteinemia (HHcy) is a well established andindependent risk factor for stroke and cardiovascular disease (CVD). Furthermore, anincreased homocysteine (Hcy) level showed a more than multiplicative effect on riskin hypertensive subjects (H-type hypertension) with a relative risk of10-folds forstroke..Objective: To obtain the prevalence of HHcy in rural Chinese hypertensivesubjects and to identify the major determiants of HHcy..Methods: We conducted a community-based cross-sectional study in two ruralregions of Northern (Lianyungang) and Southern (Anqing) China from2008to2009.The Hcy levels were measured by enzyme immunoassay methods and themethylenetetrahydrofolate reductase (MTHFR)677C/T polymorphism wasdetermined by high-throughput TaqMan allelic discrimination assay. Blood pressure(BP), body mass index (BMI) and other related demographic and lifestyle informationwere obtained through a standard questionnaire. Multivariate logistic regressionmodel was performed to evaluate the associations of HHcy with the potential riskfactors.Results: A total of21,373hypertensive patientswith the age range of45to75were available for the data analysis. Overall, the prevalence of HHcy (defined asHcy>10.0umol/L) was65.3%in males and43.0%in women in Chinese ruralhypertensive patients. Gender, age, alcohol consumption, and MTHFR677C/T wereassociated with HHcy risk. On the logistic regression analysis, multivariate modelingfurther identified that among men, the odds ratios of HHcy were significantlyincreased from1.28to3.01with age groups from50-55to70-75yrs of age,compared with the youngest reference group (45-50yrs of age). Similarly the graded increase in odds ratios of HHcy from1.45to5.74were observed with increased agegroups among women. Women in Anqing had a significantly increased prevalence ofHHcy than in Lianyungang (OR=0.85;95%CI:0.68-1.07),but not men. The subjectswith CT and TT genotype had significantly higher risks of HHcy both in men1.32(95%CI:1.19-1.47)and3.92(95%CI:3.39-4.52)Alcohol consumption issignificantly associated was20%reduction in risk of HHcy compared withnon-drinkers. Cigarette smoking is not significantly associated with HHcy in thispopulation.Conclusions: our study found that there was a high prevalence of HHcy in ruralChinese hypertensive patients and that the gender, age, and MTHFR677C/T were themajor determinants of HHcy.