Nanfang Li

The prevalence of hypertension, obesity and dyslipidemia in individuals of over 30 years of age belonging to minorities from the pasture area of Xinjiang

BackgroundThe prevalence of population-wide hypertension, obesity and dyslipidemia has not been well studied in the pasture area of Xinjiang. The present epidemiological study was performed to determine the prevalence of hypertension, obesity and dyslipidemia in minority populations from the pasture area of Xinjiang and to discuss the potential risk factors for hypertension.MethodsA population-based, cross-sectional study in the Xinjiang pasture area was performed which included 2251 participants aged over 30 years (90.33% participation rate) of whom 71.26% were Kazaks. Several risk factors were considered: hypertension (defined as systolic or diastolic blood pressure or both of at least 140/90 mmHg measured on one occasion or treatment for hypertension) overweight/obesity (body mass index ≥ 25 kg/m2) alcohol intake, smoking/tobacco use and dyslipidemia. Outcomes were prevalence of hypertension, obesity and dyslipidemia and the associated risk factors of hypertension detected by multivariate logistic regression analysis taking into account various metabolic and lifestyle characteristics.ResultsThe prevalence of hypertension, overweight/obesity and dyslipidemia in all participants from the pasture area of Xinjiang was 51.9%, 47.9% and 49.2% respectively. Independently, the prevalence and awareness of hypertension was 52.6% and 15.3% among Kazaks (n = 1604), 54.6% and 14.1% among Uygurs (n = 418), 39.5% and 16.1% among Mongolians (n = 81) and 43.9% and 18.2% among non-Xinjiang-born Han immigrants (n = 148). The prevalence of overweight/obesity in Kazaks, Uygurs, Mongolians and Han immigrants was 46.7%, 48.9%, 62.5% and 50.3%, respectively. The prevalence of dyslipidemia in the four ethnic groups mentioned was 53.5%, 34.8%, 49.3% and 47.3%, respectively. The mean blood pressure in all participants was 136/86 mmHg (pre-hypertensive), the mean BMI was 24.7 kg/m2. Based on multiple logistic regression analysis, the significant risk factors for hypertension were age [1.07(1.06-1.09), P < 0.0001], overweight/obesity [overweight: 1.61(1.22-2.13), p = 0.0007; obesity: 1.95 (1.33-2.87), p = 0.0007], hypercholesterolemia [1.30(1.15-1.47), p < 0.0001] and an alcohol intake of over 30 g/day [2.22(1.43-3.45), p = 0.0004].ConclusionsThe considerably high prevalence of hypertension, overweight/obesity and dyslipidemia among the minority population aged over 30 from the pasture area of Xinjiang calls for effective preventive measures. Age, increased body mass index, hypercholesterolemia and ≥30 g/d alcohol intake can be counted as risk factors for hypertension, but further genetic or environmental clarification would be desirable to explain the unusually high prevalence of the conditions mentioned above.

Ethnic disparities in the clustering of risk factors for cardiovascular disease among the Kazakh, Uygur, Mongolian and Han populations of Xinjiang: a cross-sectional study

BackgroundChinese Uygur, Kazakh, Mongolian and Han populations represent >90% of the total population of Xinjiang Uygur Autonomous Region, and their genetic backgrounds, customs, culture, and food consumption are different. The effect of ethnic differences on cardiovascular disease risk factors (CRFs; hypertension, obesity, diabetes, dyslipidemia, smoking) can be striking but is rarely studied. We report here the findings of the relationship among these ethnic groups and their CRFs across the four largest ethnic groups of Xinjiang.MethodsA cross-sectional survey of representative samples was conducted 2002–2008 in Chinese Uygur, Kazakh, Mongolian and Han populations (age >30 years; 4,421 Kazakh, 3884 Han, 3,218 Uygur, and 892 Mongolian individuals) in Xinjiang.ResultsA total of 90.4% of Kazakh, 91.9% of Uygur, 90.4% of Mongolian, 85.1% of Han individuals had at least one CRF. Clustering of ≥2 or ≥3 of these risk factors was noted in 65.2% or 32.1% of Kazakh, 64.8% or 33.0% of Uygur, 66.9% or 36.5% of Mongolian as well as 62.0% or 28.3% of Han subjects, respectively. Compared with the Han population, the adjusted odds ratios of ≥1, ≥2, and ≥3 CRFs for Kazakh, Uygur and Mongolian populations were higher (all P<0.001). The age-standardized prevalence of the clustering of ≥1, ≥2, and ≥3 CRFs in Kazakh, Uygur, Mongolian, and Han populations was lower than their counterparts in the NHANES Ш study (USA) but higher than in the InterASIA Study (China).ConclusionsEthnic groups living in Xinjiang had striking differences in CRFs. Ethnic-specific strategies should be developed to prevent cardiovascular disease in different ethnic groups.

Associations between genetic variations in the FURIN gene and hypertension

BackgroundHypertension is a complex disease influenced by multiple genetic and environmental factors. The Kazakh ethnic group is characterized by a relatively high prevalence of hypertension. Previous research indicates that the FURIN gene may play a pivotal role in the renin-angiotensin system and maintaining the sodium-electrolyte balance. Because these systems influence blood pressure regulation, we considered FURIN as a candidate gene for hypertension. The purpose of this study was to systematically investigate the association between genetic variations in the FURIN gene and essential hypertension in a Xinjiang Kazakh population.MethodsWe sequenced all exons and the promoter regions of the FURIN gene in 94 hypertensive individuals to identify genetic variations associated with the disorder. Genotyping was performed using the TaqMan polymerase chain reaction method for four representative common single nucleotide polymorphisms (SNPs, -7315C > T, 1970C > G, 5604C > G, 6262C > T) in 934 Kazakh Chinese people. One SNP (1970C > G) was replicated in 1,219 Uygur Chinese people.ResultsNine novel and seven known single nucleotide polymorphisms were identified in the FURIN gene. The results suggest that 1970C > G was associated with a hypertension phenotype in Kazakh Chinese (additive model, P = 0.091; dominant model, P = 0.031, allele model, P = 0.030), and after adjustment with logistic regression analysis, ORs were 1.451 (95%CI 1.106-1.905, P = 0.008) and 1.496 (95% 1.103-2.028, P = 0.01) in additive and dominant models, respectively. In addition, the association between 1970C > G and hypertension was replicated in Uygur subjects (additive model, P = 0.042; dominant model, P = 0.102; allele model, P = 0.027) after adjustment in additive and dominant models, ORs were 1.327 (95% 1.07-1.646), P = 0.01 and 1.307 (95%CI 1.015-1.681, P = 0.038), respectively. G allele carriers exhibited significant lower urinary Na+ excretion rate than non-carriers in the Kazakh Chinese population (152.45 ± 76.04 uM/min vs 173.33 ± 90.02 uM/min, P = 0.007).ConclusionOur results suggest that the FURIN gene may be a candidate gene involved in human hypertension, and that the G allele of 1970C > G may be a modest risk factor for hypertension in Xinjiang Kazakh and Uygur populations.

Genetic Variations in the KCNJ5 Gene in Primary Aldosteronism Patients from Xinjiang, China

Background Primary aldosteronism (PA) is the most common endocrine form of secondary hypertension, and one of the most common subtypes of sporadic PA is aldosterone-producing adenoma (APA). Recently, two somatic mutations of the KCNJ5 gene were implicated in APA, and two germline mutations were associated with familial hyperaldosteronism III. Objectives This case-control study was designed to investigate the relationship between genetic variations in the KCNJ5 gene and sporadic PA patients in Xinjiang, China. Methods Five common single nucleotide polymorphisms (SNPs) of the KCNJ5 gene (rs6590357, rs4937391, rs3740835, rs2604204, and rs11221497) were detected in patients with sporadic PA (n = 235) and essential hypertension (EH; n = 913) by the TaqMan polymerase chain reaction method. Results The EH group and the PA group showed significant differences in the distributions of genotypes and alleles of rs4937391 and rs2604204 in total and male subjects (P<0.05), as well as rs3740835 in male subjects (P<0.05). However, only the association between the rs2604204 genotype and male sporadic PA remained significant after Bonferroni’s correction (P<0.01). Furthermore, logistic regression analysis demonstrated that the CC genotype of rs2604204 was a risk factor for male patients with sporadic PA, after adjusting for age and body mass index (odds ratio = 2.228, 95% CI: 1.300–3.819, P = 0.004). Conclusion The genetic variant rs2604204 of KCNJ5 is associated with sporadic PA in Chinese males, suggesting that KCNJ5 may be involved in the pathogenesis of sporadic PA in these particular patients.

Higher Levels of Plasma TNF-α and Neuropeptide Y in Hypertensive Patients with Obstructive Sleep Apnea Syndrome

Resistant hypertension is always fount to be accompanied with obstructive sleep apnea syndrome (OSAS). Previous studies assumed inflammation participated in OSAS and hypertension. The fact that tumor necrosis factor a (TNF-α) was related to OSAS, while neuropeptide Y (NPY) was related to hypertension, was widely reported separately. To investigate the involvement of TNF-α and NPY simultaneously in hypertension accompanied with OSAS, 417 subjects who underwent the polymonograph and blood pressure measurement were consecutively selected. Plasma TNF-α and NPY levels were determined in normotensive with OSAS (n = 113), hypertensive without OSAS (n = 73), hypertensive with OSAS (n = 134), and those of controls (n = 97), respectively. A significant increase of plasma TNF-α and NPY were both observed in hypertensive subjects with or without OSAS, the highest level of TNF-α and NPY were in hypertension with the OSAS group. TNK-α, NPY, and neck circumference contributed to OSAS and hypertension as risk factors in the logistic regression model. Neck circumference was impacted by apnea/hyponea index, mean diastolic blood pressure, and TNF-α level, which was indicated via the multiple linear model. The present study indicated a positive interplay between plasma TNF-α, NPY, hypertension, and OSAS in the Han population of Xinjiang. Although there is evidence that inflammation plays a role in the pathophysiology of hypertension and OSAS, clear evidence is still lacking, and raises the dilemma of the hen and the egg. Further studies are needed to clarify the role of inflammation in the pathogenesis of hypertension with OSAS, in which neck size should be considered as a linked independent factor.

Genetic variation of NEDD4L is associated with essential hypertension in female Kazakh general population: a case-control study

BackgroundHypertension affects > 18.8% of adults in China. Indeed, hypertension is the most prevalent risk factor for cardiovascular morbidity and mortality worldwide. Genetic variation is thought to contribute to the etiology of hypertension. NEDD4L is a candidate gene for hypertension, both functionally and genetically. The purpose of the current study was to investigate the relationship between the variation in NEDD4L and essential hypertension in Kazakh, which is a relatively isolated population with a pure genetic background and is an ideal population to study genetic mechanisms of hypertension.MethodsWe screened the promoter and exons of NEDD4L in 94 Kazakh hypertensive individuals to identify representative variations. Then, by genotyping the representative variations in the Kazakh general population, a case-control study was conducted.ResultsBy systemically screening variations of NEDD4L, we did not identify any functional mutations in NEDD4L. A new common variation (296921-296923delTTG), which is not found in the NCBI database, was identified. Three representative variations (296921-296923delTTG, rs2288774, and rs2288775) were successfully genotyped in the Kazakh general population. The distribution of the dominant model (AA vs. AG+GG) of rs2288775, the additive model, and the recessive model (II+ID vs. DD) of 296921-296923delTTG differed significantly between the cases and controls in females (P = 0.040, P = 0.024, and P = 0.007, respectively). After adjusting for confounding factors, logistic regression analysis showed that rs2288775 (in the dominant model) and 296921-296923delTTG (in the recessive model) were significantly associated with hypertension (rs2288775: OR = 1.479, 95% CI = 1.011-2.064, p = 0.044; and 296921-296923delTTG: OR = 1.908, 95% CI = 1.020-3.568, p = 0.043) in females. The frequency of the D-C-G haplotype was significantly higher for cases than for controls in females (P = 0.020). There was a significant interaction between the NEDD4L genotype and gender (P for interaction: 0.045 for rs2288775 and 0.064 for 296921-296923delTTG), but there was no significant interaction between the NEDD4L genotype and smoking (P for interaction: 0.616 for rs2288775 and 0.447 for 296921-296923delTTG). For females and total participants, the urinary Na excretion rate was significantly lower in the DD than the I/I+I/D individuals (P = 0.032 and P = 0.027 respectively).ConclusionThe genetic variations of NEDD4L may be associated with essential hypertension in females in the Kazakh general population.

Association of Genetic Variations of Regulator of G-Protein Signaling 2 with Hypertension in the General Xinjiang Kazakh Population

Mice deficiency in regulator of G-protein signaling 2(RGS2) showed an evident hypertension phenotype. Here, we studied associations of genetic variations of RGS2 with essential hypertension in the Kazakh population. Two identified nonsynonymous mutations (K18N, Y178C) were not specific for hypertension. A significant association was observed between 1891–1892 TC insertion/deletion with hypertension in men (OR = 1.698, P = 0.03 ) and in total population (OR = 1.32, p = 0.044) in dominant model. The mean systolic blood pressure (SBP) of the ID+DD group was significantly higher than that of the II group (adjusted, p = 0.044). Our results suggest that D allele of 1891–1892 TC insertion/deletion of RGS2 might be an independent risk factor for hypertension in Xinjiang Kazakhs.

Prevalence of Primary Aldosteronism in Hypertensive Subjects with Hyperglycemia

The aim of this study was to examine the prevalence of primary aldosteronism (PA) in hypertensive patients with hyperglycemia. Two hundred and thirty-two hypertensive patients with hyperglycemia were screened for PA. Fifty-four subjects with an aldosterone/rennin activity ratio >20 ng/dL per ng/mL/hour underwent a saline loading test. Primary aldosteronism was present in 22.4% of patients with a plasma aldosterone concentration >5 ng/dL and 11.6% of those with plasma aldosterone concentrations >10 ng/dL. There were 14.0%–23.0% patients with PA in the diabetes mellitus group, 2.3%–23.3% in the impaired glucose tolerance group, and 9.1% in the impaired fasting glucose group. Primary aldosteronism is common in hypertensive individuals with hyperglycemia.

Case Detection Testing for Primary Aldosteronism in Male Patients with Hypertension and Snoring

Objectives: Coexistence of primary aldosteronism and obstructive sleep apnea in hypertension is evidenced. However, aldosterone and renin activity is varying with apnea/hypopnea index changes in subjects with resistant hypertension. Thus, the aim is to investigate the optional cutoff value for aldosterone/renin activity to screen primary aldosteronism in patients with different status of apnea/hypopnea index. Methods: 271 hypertensive male snores were evaluated via polysomnography and divided into two groups, group with apnea/hypopnea index >15 events/h and with apnea/hypopnea index 15 ng/dL performed saline infusion test, after which aldosterone concentration>5 ng/dL was a sign of primary aldosteronism. Receiver operating characteristic curve was applied to explore appropriate cutoff value for aldosterone/renin activity. Results: 39 (14.4%) of the 271 were diagnosed with primary aldosteronism including 15 with apnea/hypopnea index 15 events/h. Area under receiver operating characteristic curve was 0.97 (95%CI 0.94-0.99) in the group with apnea/hypopnea index >15 events/h and 0.91 (95%CI 0.87-0.96) in the group with apnea/hypopnea index 15 events/h with sensitivity 100%, specificity 69.7%. Youden index is 0.9 for the group with apnea/hypopnea index 15 events/h. Conclusions: Optional cutoff values of aldosterone/renin activity to screening for primary aldosteronism should be considered in patients with different status of apnea/hypopnea index.

Potential inflammatory markers in obstructive sleep apnea-hypopnea syndrome

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is a complex chronic inflammatory respiratory disease with multiple pathogenic factors and high morbidity and mortality. Serum levels of nuclear factor-κB (NF-κB), hypoxia-inducible factor-1 alpha (HIF-1α), and surfactant protein D (SPD) were investigated in OSAHS patients, to determine their clinical significance and correlation with the pathogenesis. Patients were classified into a mild and moderate OSAHS group (n = 25) and severe OSAHS group (n = 33). Twenty healthy patients served as a control group. Peripheral blood levels of NF-κB, HIF-1α, and SPD were determined by Western blot, and a correlation analysis was performed. Severe OSAHS patients received nasal continuous positive airway pressure (nCPAP) therapy and were followed up after 2 months. NF-κB p65, HIF-1α, and SPD expression levels were determined after valid nCPAP therapy. NF-κB p65 and HIF-1α expression was significantly higher in severe OSAHS group than in the other two groups (p < 0.01), and was positively correlated with the apnea-hypopnea index (AHI) (r = 0.696, p < 0.001; r = 0.634, p < 0.001). SPD expression was significantly lower in severe OSAHS group than in the control group (p < 0.01) and mild and moderate OSAHS group (p < 0.01), and was negatively correlated with AHI (r = -0.569, p < 0.001). OSAHS pathogenesis was associated with changes in NF-κB, HIF-1α, and SPD protein expression levels. nCPAP therapy could improve the clinical characteristics of the patients, lower serum NF-κB and HIF-1α levels, and increase serum SPD levels. We conclude that OSAHS is related to the expression of NF-κB, HIF-1, and SPD.