Association Between Clock&Bmal1Genes Polymorphisms And Metabolic Syndrome In Primary Hypertension Patients

Objective: To explore and discuss the relationship between Clock&Bmal1genespolymorphisms and metabolic syndrome in primary hypertension patients.Methods:197essential hypertension patients without diabetes (175patients of themhad not taken medicine,22patients only had taken calcium channel blocker) had beenselected from October2011to January2012in the Department of CardiovascularDiseases of Fujian Provincial Hospital. Hypertensive patients were divided into twogroups: metabolic syndrome group (MS, n=91) and non metabolic syndrome group(NMS, n=106). Clinical data, biochemical indicators and ambulatory blood pressuredata were recorded. Polymerase chain reaction (PCR) was used to characterize Clockgenotypes (T/C); PCR and restriction fragment length polymorphism (RFLP) wasemployed to characterize Bmal1genotypes (A/G).Results:(1) The frequency of different genotypes of Clock and Bmal1were in accordancewith Hardy-Weinberg equilibrium in our study.(P＞0.05)(2) Comparison of clinical characteristics: Compared with non-MS group, the waistcircumference, body mass index (BMI), triglyceride (TG), fasting blood glucosepressure (FBG), insulin, insulin resistance index, and glycosylated hemoglobin levelwere high in MS group (P＜0.05), whereas the proportion of women and high-densitylipoprotein cholesterol (HDL-C) were relatively low. The ages, low-densitylipoprotein cholesterol and ambulatory blood pressure monitoring data showed nosignificant difference.(3) Comparison of gene polymorphisms:①Clock gene: Compared with non-MSgroup, Clock gene TT genotype distribution frequency was less in MS group, and(χ~2=10.045, P=0.005) T allelic frequency was also less in MS group.(χ~2=11.333,P=0.001) For carriers with non-TT genotype, the possibility to get MS was twice higher than that of those with TT genotype.(OR=2.616，95%CI：1.395~4.906，P=0.002)②Bmal1gene: Compared with non-MS group, Bmal1gene GG genotypedistribution frequency was more in MS group (χ~2=11.342, P=0.003), and G allelicfrequency was also more in MS group (χ~2=8.602, P=0.001). Carriers with GGgenotype were3times more possible than those without AA genotype to get MS.(OR=3.304,95%CI:1.315~8.305, P=0.009) Compared with the AG genotype,carriers with GG genotype were twice more likely to get MS.(OR=2.715,95%CI:1.423~5.177, P=0.002)(4) The relationship between gene polymorphism and metabolic indicators:①Clockgene: Compared with TT genotype, carriers with C allelic were twice more likely toget hyper-triglyceride (P=0.024, OR=2.022,95%CI:1.090~3.750), twice possible toget impaired fasting glucose (P=0.042, OR=1.970,95%CI:1.019~3.808), twice morelikely to get insulin resistance (P=0.032,OR=2.033,95%CI:1.058~3.907).②Bmal1gene: Compared with non-GG genotype, carriers with GG genotype were twice morelikely to get impaired fasting glucose (P=0.021, OR=2.133,95%CI:1.113~4.090),twice possible to have insulin resistance (P=0.039, OR=1.962,95%CI:1.029~3.739).Conclusion: Among patients with primary hypertension, Clock gene C allelic andBmal1gene GG genotype have a high distribution frequency in metabolic syndromewhich may possibly be caused by genetic susceptible factors of the metabolicsyndrome.