Common SNPs of APM1 Gene Are Not Associated With Hypertension or Obesity in Chinese Population

Objective To investigate whether the common variants 45T/G and 276G/T in APM1 gene were associated with hypertension combined with obesity （HO） and related clinical features in Chinese Han population. Methods A case-control study design was applied. Common polymorphisms of 45T/G and 276G/T were genotyped by PCR product sequencing in 484 cases with HO and 502 controls with normal blood presure and BMI 〈 25. Results The genotype and allele frequencies of 45T/G, 276G/T, and haplotype defined by the two variants in cases did not differ from those in controls. The means of blood pressure, BMI and waist-hip ratio did not differ among genotypes of the two polymorphisms and haplotypes. Among lipid profiles, only serum high-density lipoprotein cholesterol （HDL-C） levels were significantly lower in T allele carders than that in non-T carriers after adjusting possible confounding factors （1.21 vs 1.32 mmol/L, P=0.0001）. Condusion Polymorphisms of 45T/G and 276G/T in APM1 gene are not associated with hypertension or obesity, or their clinical features in Chinese Han population. Common polymorphism of 45T/G might be associated with serum HDL-C levels in Chinese.

Ethnic Differences in Body Mass Index and Prevalence of Obesity in School Children of Urumqi City, Xinjiang, China

Objective To investigate the prevalence of obesity and distribution of body mass index （BMI） in school children of four ethnic groups in Urumqi, Xinjiang, China. Methods A total of 55 508 school children of Han, Hui, Uygur and Kazak nationalities aged 8-18 years were selected by a cluster sampling from a districts of Urumqi City for anthropometrie measurement and demographic survey. Prevalence of obesity and overweight and distribution of body mass index （BMI） by gender, age, and nationality were analyzed and compared. Cutoff points of BMI for defining obesity and overweight were based on the proposal set by the Working Group on Obesity in China （WGOC） to assess age-, gender- and nationality-specific prevalence of obesity and overweight. Results Prevalence of obesity was 5.34%, 6.78%, 3.39 %, and 1.22% for boys and 2.61%, 1.83%, 1.78%, and 1.40% for girls of Han, Hui, Uygur and Kazak nationalities, respectively. Prevalence of obesity tended to decrease with age overall, whereas that of overweight increased with age in Han children. Conclusions Prevalence of obesity in school children in Urumqi varies with their nationalities and is lower than that of an average national level and a level of western countries. Obesity is more prevalent in boys than in girls of Urmuqi overall, which is just the opposite in Kazak children. Han boys and Hui girls have the highest prevalence of obesity and Kazak boys and girls have the lowest ones. Prevalence of obesity decreases with age, but that of overweight shows a different trend.

Linkage analysis of chromosome 14 and essential hypertension in Chinese population

Background Hypertension is a complex biological trait that influenced by multiple factors. The encouraging results for hypertension research showed that the linkage analysis can be used to replicate other studies and discover new genetic risk factors. Previous studies linked human chromosome 14 to essential hypertension or blood pressure traits. With a Chinese population, we tried to replicate these findings.Methods A linkage about lO centi Morgen analysis and exclusion was performed with the scan was performed on chromosome 14 with 14-microsatellite markers with a density of （cM） in 147 Chinese hypertensive nuclear families. Muhipoint non-parametric linkage mapping were performed with the GENEHUNTER software, whereas quantitative analysis variance component method integrated in the SOLAR package.Results In the qualitative analysis, the highest non-parametric linkage score is 1.0 （ P=0.14） at DI4S261 in the single point analysis, and no loci achieved non-parametric linkage score more than 1.0 in the multipoint analysis. Maximum-likelihood mapping showed no significant results, either. Subsequently the traditional exclusion criteria of the log-of-the-odds score-2 were adopted, and the chromosome 14 with λs≥ 2.4 was excluded. In the quantitative analysis of blood pressure with the SOLAR software, two-point analysis and multipoint analysis suggested no evidence for linkage occurred on chromosome 14 for systolic and diastolic blood pressure.Conclusion There was no substantial evidence to support the linkage of chromosome 14 and essential hypertension or blood pressure trait in Chinese hypertensive subjects in this study.

Association study of the endothelial nitric oxide synthase gene polymorphisms with essential hypertension in northern Han Chinese

Background Nitric oxide （NO） synthesized by endothelial nitric oxide synthase （eNOS） plays an important role in both the regulation of endothelial function and the control of blood pressure. Up to now, there has been conflicting data regarding the association between three clinically relevant polymorphisms （T-786C, intron4b/a and G894T） of the eNOS gene and essential hypertension.

Modulation of KCNQ1 current by atrial fibrillation-associated KCNE4 (145E/D) gene polymorphism

Background Atrial fibrillation is a common arrhythmia with multi-factorial pathogenesis. Recently, a single nucleotide polymorphism （G/T） at position 1057 in the KCNE4 gene, resulting in a glutamic acid （Glu, E）/aspartic acid （Asp, D） substitution at position 145 of the KCNE4 peptide, was found in our laboratory to be associated with idiopathic atrial fibrillation （atrial fibrillation more frequent with KCNE4 145D）. However, the functional effect of the KCNE4 145E/D polymorphism is still unknown. Methods We constructed KCNE4 （145E/D） expression plasmids and transiently co-transfected them with the KCNQ1 gene into Chinese hamster ovary-K1 cells and performed whole-cell patch-clamping recording to identify the possible functional consequences of the single nucleotide polymorphism. Quantitative data were analyzed by Student＇s t test. Probability values less than 0.05 were considered statistically significant. Results A slowly activating, non-inactivating voltage-dependent current （（24.0±2.9） pA/pF, at ＋60 mV）） could be recorded in the cells transfected with KCNQ1 alone. Co-expression of wild type KCNE4 inhibited the KCNQ1 current （（7.3± 1.1 ） pA/pF））. By contrast, co-expression of KCNE4 （145D） augment the KCNQ 1 current （（42.9 ±3.7） pA/pF））. The V1/2 of activation for the KCNQI/KCNE4 （145D） current was shifted significantly towards the depolarizing potential compared to that for the KCNQ1 current （（-2.3±0.2） mv vs （-13.0±1.5） mv, P 〈 0.01）） without changing the slope factorK. Furthermore, KCNE4 （145D） also affected the activation and deactivation kinetics of KCNQ1 channels. Conclusion We provide experimental evidence that the KCNE4 （145E/D） polymorphism exerts the effect of ＂gain of function＂ on the KCNQ1 channel. It may underlie the genetic mechanism of atrial fibrillation. Further studies on the functional association between IKs and KCNE4 （145D） polymorphism in cardiac myocytes are suggested.