Guliang Wang

Is isolated nocturnal hypertension a novel clinical entity? : Findings from a chinese population study

We reported previously that normotensive Chinese had higher nighttime diastolic blood pressure compared with non-Chinese. We, therefore, studied the prevalence and characteristics of isolated nocturnal hypertension (HT) and its association with arterial stiffness, an intermediate sign of target organ damage. We recorded ambulatory blood pressure, the central and peripheral systolic augmentation indexes, the ambulatory arterial stiffness index, and brachial-ankle pulse wave velocity in 677 Chinese enrolled in the JingNing population study (53.6% women; mean age: 47.6 years). Prevalence was 10.9% for isolated nocturnal HT (≥120/70 mm Hg from 10:00 pm to 4:00 am), 4.9% for isolated daytime HT (≥135/85 mm Hg from 8:00 am to 6:00 pm), and 38.4% for day-night HT. Patients with isolated nocturnal HT, compared with subjects with ambulatory normotension (45.8%), were older (53.7 versus 40.7 years), more often reported alcohol intake (68.9% versus 51.0%), had faster nighttime pulse rate (62.8 versus 60.7 bpm), had higher serum cholesterol (5.12 versus 4.77 mmol/L), and had higher blood glucose (4.84 versus 4.38 mmol/L). Similar to patients with isolated daytime HT or day-night HT, patients with isolated nocturnal HT had higher indexes of arterial stiffness (P<0.05) than subjects with ambulatory normotension (central augmentation index: 140% versus 134%; peripheral augmentation index: 82.6% versus 76.5%; ambulatory arterial stiffness index: 0.40 versus 0.35 U; brachial-ankle pulse wave velocity: 16.2 versus 14.7 m/s). Of 74 patients with isolated nocturnal HT, only 4 (5.4%) had hypertension on conventional office blood pressure measurement (≥140/90 mm Hg). In conclusion, isolated nocturnal HT can only be diagnosed by ambulatory blood pressure monitoring, is prevalent among Chinese, and is associated with increased arterial stiffness.

Evidence for Association of Polymorphisms in CYP2J2 and Susceptibility to Essential Hypertension

Objective Evidence from animal models and human studies suggests that CYP2J2 plays a mechanistic role in the development of hypertension. The present study aims to investigate the potential genetic contribution of the CYP2J2 gene to the etiology of essential hypertension (EH) and individual blood pressure.

Anthropometric and lifestyle factors associated with white-coat, masked and sustained hypertension in a Chinese population

Objective We investigated to what extent anthropometric and lifestyle factors contributed to the classification of Chinese individuals into groups with white-coat, masked and sustained hypertension (HT). Methods We measured the office and ambulatory blood pressure (BP) in 694 Chinese enrolled in the JingNing population study (45.7% men; mean age, 48.4 years). In multivariate-adjusted analyses, we determined the correlates of both types of BP and the factors contributing to white-coat HT (conventional and daytime BP ≥140/90 and <135/85 mmHg, respectively), masked HT (<140/90 and ≥135/85 mmHg) and sustained HT (≥140/90 and ≥135/85 mmHg), relative to normotension (<140/90 and <135/85 mmHg). Results In continuous analyses, the conventional and daytime BPs were positively associated with age, body mass index and urinary sodium, and inversely with urinary potassium. The prevalence of white-coat, masked and sustained HT was 7.8, 10.8, and 35.0%, respectively. In line with the continuous analyses, the risk of sustained hypertension increased with age [odds ratio (OR), 2.11 per 10 years], body mass index (OR, 1.27 per 1 kg/m2) and urinary sodium (OR, 1.18 per 50 mmol/day), but was inversely associated with urinary potassium (OR, 0.34 per 25 mmol/day). Furthermore, the risk of white-coat and masked HT increased with age (OR, 1.79 and 1.40, respectively) and body mass index (OR, 1.14 and 1.12). Women were less likely to have masked hypertension than men (OR, 0.39). Conclusions Sex, age, body mass index, and urinary sodium and potassium excretion contribute to the risk of white-coat, masked and sustained HT in Chinese.

Family-based associations between the angiotensin- converting enzyme insertion/deletion polymorphism and multiple cardiovascular risk factors in Chinese.

Objective We investigated, in a sample of Chinese families, the associations of body mass index (BMI), blood pressure (BP), serum lipids, fasting plasma glucose, serum creatinine and uric acid with the insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene. Methods We genotyped 902 subjects from 186 nuclear families recruited in Shanghai, China, via a specialized hypertension clinic. We performed family-based association analyses for continuous and dichotomous phenotypic measurements using the quantitative and sib- transmission/disequilibrium tests (QTDT and Sib-TDT), respectively. Results The study sample included 121 parents and 781 offspring from 25 two-parent families, 71 one-parent families, and 90 families without parental information. The median number of offspring was four (range from 2 to 10). Of the 654 (85.4%) hypertensive offspring, 458 took antihypertensive drugs. The 354 male offspring were slightly younger than the 427 female siblings (48.1 versus 49.2 years, P = 0.03), but they had similar BMI (25.1 kg/m2). In 482 informative offspring, QTDT analyses demonstrated a significant association between BMI and the transmission of the ACE D allele (regression coefficient 0.563, χ2 = 4.02, P = 0.04). In 106 families with at least one hypertensive offspring and at least one normotensive sibling, Sib-TDT analyses showed that the ACE D allele was slightly over-transmitted from heterozygous parents to hypertensive offspring (P = 0.08). Conclusions Our family-based study suggests that in Chinese, the ACE I/D polymorphism might play a role in the development of obesity and hypertension, which are closely linked cardiovascular risk factors.

Linkage analysis of five candidate genes and essential hypertension in 106 Chinese nuclear families

Five candidate genes including the lipoprotein lipase, leptin, leptin receptor, α-adducin and β3 adrenergic receptor were selected to examine their possible contribution to essential hypertension (EH) in a Chinese population. On each side of the candidate gene loci, one to two highly polymorphic microsatellite markers were genotyped in 474 subjects recruited from 106 hypertension nuclear families in Shanghai. Both parametric and nonparametric linkage analyses were carried out using GENEHUNTER (version 2.0) after genotyping. Extended transmission disequilibrium testing (ETDT) was also conducted to detect preferential transmission of alleles to affected offspring. We failed to find the linkage between all these loci and EH by either parametric or nonparametric analysis, nor did we detect any significant transmission disequilibrium by ETDT. Our findings provide no support for a significant contribution of these five genes to the pathogenesis of EH among Shanghai people.

Association between Genetic Variation in Transforming Growth Factors β1 and β3 and Renal Dysfunction in Non-Diabetic Chinese

Genetic variants of transforming growth factor (TGF) β1 have been reported to be associated with diabetic nephropathy. Few studies investigated polymorphisms in the TGF-β1 and TGF-β3 genes in relation to renal dysfunction in non-diabetic subjects. In all, 601 non-diabetic Chinese were genotyped for the TGF-β1 T869C and TGF-β3 IVS3-98G>A polymorphisms by PCR-restriction fragment length polymorphism and real-time allele-specific PCR, respectively. Renal dysfunction was defined as a predicted glomerular filtration rate (GFR) of 60mL/min/1.73m2 or less. 24-hour urinary albumin excretion was measured by an immunonephelometric assay in 352 hypertensive subjects. Our study sample included 184 (30.6%) women, 396 (65.9%) hypertensive patients (65.9%), and 94 (15.6%) patients with renal dysfunction. In men but not women, the TGF-β1 TC genotype was significantly (p = 0.0005) overrepresented in patients with renal dysfunction (52.2% vs 36.8% in subjects with normal renal function). Accordingly, in men, with adjustment for age, body mass index, and systolic and diastolic blood pressure, serum creatinine concentration was significantly (p ≤ 0.03) higher in the TC heterozygotes than TT and CC homozygotes. Furthermore, in 231 male hypertensive patients, with similar adjustments applied, 24-hour urinary albumin excretion was significantly (p = 0.02) higher in the IVS3-98 AA homozygotes than G allele carriers. In further multivariate regression analysis, only in men, TGF-β1 and TGF-β3 genotypes as independent predictors had statistically significant effect on serum creatinine (p = 0.007) and urinary albumin excretion (p = 0.022), respectively. Our study demonstrated the associations of genetic variants in the TGF-β genes with renal dysfunction and albuminuria in non-diabetic Han Chinese men but not women.