Anthropometric and metabolic phenotypes in relation to the ADRA2B deletion/insertion polymorphism in Chinese population

Blood pressure and urinary sodium excretion in relation to 16 genetic polymorphisms in the natriuretic peptide system in Chinese

We systematically investigated the association between single nucleotide polymorphisms (SNPs) in the natriuretic peptide system (NPPA, NPPB, NPPC, NPRA, NPRC, and Corin genes) and blood pressure in a Chinese population. The study population was recruited from a mountainous area 500 km south of Shanghai from 2003 to 2009. Using the ABI SNapShot method, we first genotyped 951 subjects enrolled in 2005 for 16 SNPs and then the remaining 1355 subjects as validation for 5 SNPs selected from the primary study. Overall, the association of the studied genetic polymorphisms with blood pressure and urinary excretion of cations was weak or non-significant. However, in the primary study, there was significant (Pint = 0.003) interaction between the rs198358 polymorphism and age in relation to diastolic blood pressure. After adjustment for covariates, diastolic blood pressure was significantly higher in the G allele carriers than AA homozygotes in 176 subjects aged 60 years or older (77.8 ± 1.72 vs 73.9 ± 1.54 mmHg, P = 0.001). In the primary combined with validation studies, this interaction remained statistically significant (Pint = 0.02). The odds ratio of hypertension for carrying the G allele versus AA homozygotes was 1.25 (95% CI: 1.03-1.52; P = 0.03) in all subjects, and 0.85 (0.51-1.41; P = 0.53), 1.30 (0.98-1.73; P = 0.06), and 1.45 (0.95-2.22; P = 0.08) in the subjects younger than 40 years, 40-59 years, and 60 years or older, respectively. Some of the genetic polymorphisms in the natriuretic peptide system might be associated with blood pressure. However, not only the size, but also the direction of the association may change with age.

A functional common polymorphism of the ABCB1 gene is associated with chronic kidney disease and hypertension in Chinese

BACKGROUND

Permeability glycoprotein is encoded by the ATP-binding cassette B1 gene (ABCB1) and is an extruder of toxic metabolites in the kidney. A functional common polymorphism (C3435T, rs1045642) in the human ABCB1 gene has been found to be associated with allograft outcome in kidney transplant patients. In this study, we investigated the association of the C3435T polymorphism with renal function and blood pressure (BP) in 2 Chinese populations.

METHODS

The discovery and replication populations were recruited from a mountainous area (Zhejiang Province) and a newly urbanized suburban area (Shanghai), respectively. We genotyped all subjects using the ABI SNapShot method. Chronic kidney disease (CKD) was defined as an estimated glomerular filtration rate <60 ml/min × 1.73 m(2) or 24-hour urinary albumin excretion ≥30 mg.

RESULTS

In the discovery population of 1,987 subjects, after adjustment for covariables, TT homozygosity (n = 217) was associated with a higher risk of CKD (n = 369; odds ratio (OR) = 1.73; P = 0.003) and with higher systolic BP (+3.1 mm Hg; P = 0.03) and pulse pressure (+3.4 mm Hg; P = 0.001). These associations were dependent on age (Pint ≤ 0.05). In subjects aged ≥60 years (n = 374), the corresponding OR or difference was 2.40 for CKD, 15.1 mm Hg for systolic BP, and 12.4 mm Hg for pulse pressure (P < 0.001). In similar adjusted analyses in the replication population of 2,427 elderly (≥60 years) subjects, TT homozygosity was also associated with a higher risk of CKD (OR = 1.39; P = 0.02) and an enhanced association of hypertension with CKD (OR = 1.50; P = 0.04).

CONCLUSIONS

The ABCB1 C3435T polymorphism might predict CKD, especially in the elderly.

Physical activity modifies the association between CYBA gene polymorphisms and small artery elasticity in a Chinese population

Emerging evidence suggests that increased superoxide production is responsible for a significant proportion of endothelial dysfunction. The relationship between variants of the CYBA gene and cardiovascular diseases is currently debated. In the present study, we investigated the influence of CYBA polymorphisms (rs1049255 and rs7195830) on arterial elasticity in a Chinese population. In the 2178 participants enrolled in the GaoYou study, we measured large artery elasticity (C1) and small artery elasticity (C2) non-invasively, genotyped the CYBA polymorphisms and calculated energy expenditure. The AA genotype of the rs1049255 polymorphism was associated with a lower C2 than were the GG/AG genotypes (5.31±0.11 vs. 5.52±0.06 ml mm Hg(-1) × 100; P=0.01). Further analyses revealed an interaction between CYBA polymorphisms and physical activity with respect to C2 (P=0.007 for rs1049255 and P=0.038 for rs7195830). In less physically active participants, the AA genotype of the rs1049255 polymorphism was associated with a significantly lower C2 than the GG/AG genotypes (4.69±0.16 vs. 5.26±0.19 ml mm Hg(-1) × 100; P=0.008). In physically active participants, the GG/AG genotypes of rs7195830 polymorphism were correlated with higher C2 values than the AA genotype (5.84±0.08 vs. 5.08±0.32 ml mm Hg(-1) × 100; P=0.049). Haplotype analyses revealed higher C2 values in rs1049255G-rs7195830G carriers (P=0.0015). In conclusion, the rs1049255 and rs7195830 polymorphisms of the CYBA gene were associated with C2 in a Chinese population; physical activity could modify this genetic effect.

Peripheral and central augmentation indexes in relation to the CYP4F2 polymorphisms in Chinese

OBJECTIVE

Cytochrome (CYP) 4F2 isoform is a key metabolizing enzyme for the renal 20-hydroxyeicosatetraenoic acid (20-HETE), which, as an endogenous vasoconstrictor, may influence properties of the peripheral muscular arteries and arterioles. We, therefore, investigated the CYP4F2 polymorphisms in relation to arterial wave reflections, as measured by augmentation indexes (AIx) in Chinese.

METHODS

We performed arterial measurements by SphygmoCor and genotyped three CYP4F2 polymorphisms (V433M, rs3093089, and rs3093098) by PCR-restriction fragment length polymorphism in 1421 participants enrolled in the JingNing Population study. A replication study for the V433M polymorphism was performed in 924 Chinese recruited from a workplace setting. Urinary 20-HETE concentration was determined by ELISA in a randomly selected subsample of 318 JingNing individuals.

RESULTS

In spite of the fact that genetic associations were not significant (P ≥ 0.12) in all JingNing participants, there was significant (Pint ≤ 0.02) interaction of the V433M polymorphism with sex and pulse rate in relation to peripheral and central AIx. M433 allele carriers, compared with V433V homozygotes, had significantly greater peripheral (+5.0%, P = 0.0002) and central AIx (+3.2%, P = 0.001) in 693 men. The corresponding values were +2.7% (P = 0.04) and +1.9% (P = 0.04) in 490 individuals of the top tertile of pulse rate (≥ 76 beats/min), and were +4.0% (P = 0.02) and +3.3% (P = 0.02) in 315 replication participants with a pulse rate at least 76 beats/min. Urinary 20-HETE concentration was significantly higher (P = 0.002) in M433M (2.06 ng/ml) and V433M (1.13 ng/ml) individuals than in V433V homozygotes (0.98 ng/ml).

CONCLUSION

The CYP4F2 V433M polymorphism is associated with the size of arterial wave reflections in male Chinese, or individuals with a faster pulse rate.

Lack of association between ADRA2B-4825 gene insertion/deletion polymorphism and migraine in Chinese Han population

OBJECTIVE

The present study aimed to estimate the association between susceptibility to migraine and the 12-nucleotide insertion/deletion (indel) polymorphism in promoter region of alpha(2B)-adrenergic receptor gene (ADRA2B).

METHODS

A case-control study was carried out in Chinese Han population, including 368 cases of migraine and 517 controls. Genomic DNA was extracted from blood samples, and DNA fragments containing the site of polymorphism were amplified by PCR. Data were adjusted for sex, age, migraine history and family history, and analyzed using a logistic regression model.

RESULTS

There was no association between indel polymorphism and migraine, at either the allele or the genotype level.

CONCLUSION

These findings do not support a functional significance of ADRA2B indel polymorphism at position -4825 relative to the start codon in the far upstream region of the promoter in the present migraine subjects.