Association between serum uric acid levels and cerebral white matter lesions in Chinese individuals.

PURPOSE/AIM OF THE STUDY: We aimed to evaluate the association between serum uric acid (SUA) levels and cerebral white matter lesions (WMLs) in Chinese individuals. MATERIAL AND METHODS: We prospectively identified patients aged 50 years and older in neurology department from July 2014 to March 2015. Both periventricular WMLs (P-WMLs) and deep WMLs (D-WMLs) were identified on magnetic resonance imanging (MRI) scans and the severity was graded using the Fazekas method. Multivariate logistic regression analyses were performed to examine the association between SUA and WMLs. RESULTS: A total of 480 eligible participants were enrolled in this study. SUA level in severe group was much higher than that in mild group (for P-WMLs: 320.21 ± 79.97 vs. 286.29 ± 70.18, p = 0.000; for D-WMLs: 314.71 ± 74.74 vs. 290.07 ± 74.04, p = 0.031). Subgroup analyses showed that higher SUA level was associated with higher severity of P-WMLs in women, but not in male patients. Multivariate logistic regression analyses showed that SUA was still associated with increased risk of higher severity of P-WMLs (OR = 1.003, 95% = 1.000-1.006), but not D-WMLs. CONCLUSION: Elevated SUA level was independently associated with greater odds of higher severity of P-WMLs, particularly in women.

The role of TRPV1 in improving VSMC function and attenuating hypertension.

The transient receptor potential vanilloid type 1 (TRPV1) channel, a ligand-gated cation channel of the TRP subfamily, can be activated by multiple stimuli, including capsaicin. Currently, cumulative studies have demonstrated an interesting link between TRPV1 and cardiovascular diseases, including hypertension. Additionally, the protective effect of TRPV1 against hypertension and its related disorders has been proved to be partly involved with the improved action of vascular smooth muscle cells (VSMCs). This review focuses on the current knowledge of TRPV1 in improving VSMC function and attenuating hypertension.

The association between leukoaraiosis and carotid atherosclerosis: a systematic review and meta-analysis.

The association between large-artery atherosclerosis and leukoaraiosis (LA) has been increasingly reported with inconsistent conclusion. This systematic review examines the relationship between LA and carotid atherosclerosis, manifested as atherosclerotic stenosis, plaques and increased intima-media thickness (IMT). PubMed, Embase, and Web of Science were searched for articles published up to February 2014. Thirty-two studies that examined the relationship between LA and carotid atherosclerosis were included. All statistical analysis was conducted with Review Manager 5.2.4. Finally, 32 studies including 17,721 patients were identified. There were 7 (30%) out of 23 studies reporting significant association between LA and carotid stenosis; 11 (79%) out of 14 studies reporting significant association between LA and carotid plaque; all 9 studies reporting significant association between LA and carotid IMT; one study showing an association between LA and CAWT (similar to the role of the IMT). The quantitative meta-analysis of 10 studies showed that carotid atherosclerosis was not associated with LA (OR: 1.10; 95% CI: 0.61-1.98). A significant association was found between LA and carotid plaque (OR = 3.53; 95% CI = 1.83-6.79), and the result of IMT group showed that IMT increased risk of LA (MD = 0.11; 95% CI = 0.01-0.22). This systematic review suggested that LA has a tendency of association with carotid plaques but no association with simple carotid stenosis.

Telmisartan-induced PPARγ activity attenuates lipid accumulation in VSMCs via induction of autophagy.

Foam cell formation is the hallmark of atherosclerosis. Both telmisartan and autophagy protect against the development of atherosclerosis. However, it has yet to be elucidated whether telmisartan prevents vascular smooth muscle cell (VSMC)-derived foam cell formation. Vascular smooth muscle cells isolated from the thoracic aorta of male C57BL/6J mice were used for this study. To induce foam cell formation, primary VSMCs were incubated in 80 µg/ml oxLDL for 24 h. LC3, beclin-1, PPARγ, AMPK, p-AMPK, mTOR and p-mTOR expression were determined via Western blot. Lipid accumulation was evaluated via oil red O staining and intracellular total cholesterol level measurement. Our study demonstrated that telmisartan dose-dependently increased the expression of beclin-1, the LC3II/LC3I ratio and the quantity of GFP-labeled autophagosomes, displaying a peak effect at 10 µM. In control siRNA-transfected VSMCs, telmisartan (10 µM) decreased lipid droplet accumulation and the total cholesterol level significantly. In contrast, in Atg7 siRNA-transfected VSMCs, telmisartan failed to attenuate lipid accumulation. In addition, telmisartan dose-dependently increased the expression of PPARγ and p-AMPK and decreased the expression of p-mTOR. GW9662 attenuated the telmisartan-induced increase in PPARγ expression, the LC3-II/LC3-I ratio and p-AMPK expression and the telmisartan-induced decrease in p-mTOR expression. Compound C restored mTOR activity and abolished the increase in the LC3-II/LC3-I ratio. Rapamycin significantly reduced p-mTOR expression and increased the LC3-II/LC3-I ratio. In conclusion, this study provides evidence that the chronic pharmacological activation of the PPARγ-mediated autophagy pathway using telmisartan may represent a promising therapeutic strategy for atherosclerosis.

Association between intercellular adhesion molecule-1 gene K469E polymorphism and the risk of stroke in a Chinese population: a meta-analysis.

Several epidemiologic studies have evaluated the association between intercellular adhesion molecule-1 (ICAM-1) gene K469E polymorphism and stroke, but the results were inconsistent. The present meta-analysis was performed to investigate the relationship between K469E polymorphism and stroke in the Chinese population. A comprehensive search for related studies from the electronic databases of PubMed, Embase, Web of Science, CBMdisc and CNKI as well as a manual search of the references of identified articles was performed. Data were extracted to calculate for allelic, additive, dominant and recessive models using pooled odds ratios (ORs) along with 95% confidence intervals (CIs) by Review Manager 5.0 and Stata 11.0. Different effect models, subgroup analysis, sensitivity analysis, publication bias and power calculations were used to improve the comprehensive analysis. Finally, a total of 12 studies containing 1593 cases and 1555 controls were included in the final meta-analysis. No evidence of significant association between ICAM-1 gene K469E polymorphism and stroke was found in all four models (allelic model: OR = 1.07, 95%CI = 0.78-1.47; additive model: OR = 1.21, 95% CI = 0.67-2.16 (EE vs. KK); OR = 1.04, 95%CI = 0.75-1.45 (EK vs. KK); dominant model: OR = 1.07, 95% CI = 0.73-1.56; and recessive model: OR = 1.18, 95% CI = 0.77-1.83, respectively) based on the overall population, as well as subgroup analysis and sensitivity analysis. In conclusion, the present meta-analysis showed no evidence of significant association between ICAM-1 gene K469E polymorphism and stroke in the Chinese population. Nonetheless, this conclusion should be interpreted cautiously due to the low statistical power and considerable heterogeneity. Therefore, larger sample-size studies with homogeneous cases and well-matched controls are needed to further address this correlation.

A meta-analysis of the relationship between MTHFR gene A1298C polymorphism and the risk of adult stroke.

BACKGROUND: The association between methylenetetrahydrofolate reductase (MTHFR) gene A1298C polymorphism and adult stroke remains controversial. The present article was designed to clarify this relationship through pooled analysis of the numerous epidemiological studies focusing on this association. METHODS: We comprehensively searched all published papers in electronic database including PubMed, Embase, Web of Science, Chinese Biomedical Literature on disc (CBMdisc) and China National Knowledge Infrastructure (CNKI) up to 2013. The pooled odds ratios (ORs) with 95% confidence intervals (CIs) for allelic (C allele vs. A allele), additive (CC vs. AA), dominant (CC+AC vs. AA), and recessive (CC vs. AA+AC) models were calculated. Subgroup and sensitivity analyses were performed to detect the heterogeneity and examine the reliability of results, respectively. Begg's funnel plots and Egger's regression test were used to assess the potential publication bias. RESULTS: A total of fifteen studies containing 2,361 cases and 2,653 controls were included in the final meta-analysis. The combined results of overall analysis showed that there was significant association between MTHFR gene A1298C polymorphism and adult stroke (allelic model: OR=1.36, 95% CI=1.11-1.67; additive model: OR=1.88, 95% CI=1.12-3.18; dominant model: OR=1.33, 95% CI=1.08-1.65 and recessive model: OR=1.77, 95% CI=1.07-2.94, respectively). On subgroup analysis by ethnicity of study population, significant association was shown in meta-analysis based on Asian population (allelic model: OR=1.40, 95% CI=1.19-1.65; additive model: OR=2.58, 95% CI=1.34-4.96; dominant model: OR=1.44, 95% CI=1.20-1.73 and recessive model: OR=2.12, 95% CI=1.20-3.76, respectively), but not in Caucasian population (allelic model: OR=1.30, 95% CI=0.93-1.82; additive model: OR=1.65, 95% CI=0.81-3.33; dominant model: OR=1.17, 95% CI=0.86-1.61 and recessive model: OR=1.70, 95% CI=0.83-3.50, respectively). In addition, the heterogeneity was effectively removed or decreased by limiting the included studies with population of Asian ethnicity. Furthermore, the corresponding pooled ORs were not materially changed in all genetic models of meta-analysis after limiting the included studies with population-based controls. However, except the recessive model, publication bias presented in the allelic, additive, dominant models identified by the Begg's funnel plots and Egger's regression test. CONCLUSIONS: In conclusion, the overall analysis suggests that MTHFR gene A1298C polymorphism plays an important role in the development of adult stroke. Genotype CC of MTHFR-1298A/C could increase the risk of stroke and may act as a predictor for clinical evaluation, especially in the Asian population. More studies with large-scale and different ethnicities are required to further confirm our findings.

Association of MTHFR C677T polymorphism and risk of cerebrovascular disease in Chinese population: an updated meta-analysis.

A variety of epidemiological studies have evaluated the association between methylenetetrahydrofolate reductase (MTHFR) gene C677T polymorphism and cerebrovascular disease, but the results were inconsistent. The present meta-analysis was therefore performed to investigate the relationship between C677T polymorphism and cerebrovascular disease in Chinese population. Systematically searching for related studies from PubMed, Embase, Web of Science, CBMdisc and CNKI databases up to 20 September 2013 and manual searching of the reference lists of identified articles was performed. Information was extracted to calculate for the additive, dominant, and recessive models using the pooled odds ratios (ORs) along with 95 % confidence intervals (CIs), using Review Manager 5.0, STATA 11.0 and SPSS 17. Logistic regression, fixed or random effects model, subgroup analysis, sensitivity analysis, meta-regression analysis and publication bias were conducted to improve the comprehensive analysis. A total of 68 case-control studies containing 7,990 cases and 6,941 controls were included in the final meta-analysis. Evidence of significant association between C677T polymorphism and risk of cerebrovascular disease was found in all three genetic models (additive model OR 1.472, 95 % CI 1.368-1.585, P L < 0.001 (CT vs. CC); OR 1.819, 95 % CI 1.666-1.985, P L < 0.001 (TT vs. CC); dominant model OR 1.77, 95 % CI 1.57-1.98, p < 0.00001; and recessive model OR 1.54, 95 % CI 1.39-1.71, p < 0.00001, respectively) based on the overall population. In addition, the results were verified by the subgroup analysis and sensitivity analysis. The present meta-analysis suggests that MTHFR gene C677T polymorphism is significantly associated with increased risk of cerebrovascular disease. TT genotype may act as an independent risk factor for cerebrovascular disease in Chinese population.

Influence of ATP-binding cassette transporter 1 R219K and M883I polymorphisms on development of atherosclerosis: a meta-analysis of 58 studies.

BACKGROUND: Numerous epidemiological studies have evaluated the associations between ATP-binding cassette transporter 1 (ABCA1) R219K (rs2230806) and M883I (rs4149313) polymorphisms and atherosclerosis (AS), but results remain controversial. The purpose of the present study is to investigate whether these two polymorphisms facilitate the susceptibility to AS using a meta-analysis. METHODS: PubMed, Embase, Web of Science, Medline, Cochrane database, Clinicaltrials.gov, Current Controlled Trials, Chinese Clinical Trial Registry, CBMdisc, CNKI, Google Scholar and Baidu Library were searched to get the genetic association studies. All statistical analyses were done with Stata 11.0. RESULTS: Forty-seven articles involving 58 studies were included in the final meta-analysis. For the ABCA1 R219K polymorphism, 42 studies involving 12,551 AS cases and 19,548 controls were combined showing significant association between this variant and AS risk (for K allele vs. R allele: OR = 0.77, 95% CI = 0.71-0.84, P<0.01; for K/K vs. R/R: OR = 0.60, 95% CI = 0.51-0.71, P<0.01; for K/K vs. R/K+R/R: OR = 0.69, 95% CI = 0.60-0.80, P<0.01; for K/K+R/K vs. R/R: OR = 0.74, 95% CI = 0.66-0.83, P<0.01). For the ABCA1 M883I polymorphism, 16 studies involving 4,224 AS cases and 3,462 controls were combined. There was also significant association between the variant and AS risk (for I allele vs. M allele: OR = 0.85, 95% CI = 0.77-0.95, P<0.01). CONCLUSIONS: The present meta-analysis suggested that the ABCA1 R219K and M883I polymorphisms were associated with the susceptibility to AS. However, due to the high heterogeneity in the meta-analysis, the results should be interpreted with caution.

Toll-like receptor 4 gene Asp299Gly polymorphism in ischemic cerebrovascular disease: a meta-analysis.

Epidemiological studies have evaluated the association between Toll-like receptor 4 (TLR4) gene Asp299Gly (rs4986790) polymorphism and the risk of ischemic cerebrovascular disease, but the results are inconsistent. In an effort to clarify earlier inconclusive results, a meta-analysis was performed. We searched the PubMed, Web of Science, Embase, Cochrane database, Clinicaltrials.gov, Current Controlled Trials, CNKI, CBMdisc, Chinese Clinical Trial Registry and Google Scholar until up to 20 July 2013. Additionally, hand searching of the references of identified articles was performed. Original observational studies investigating the association between TLR4 gene Asp299Gly polymorphism and ischemic cerebrovascular disease risk were included. All statistical analyses were performed using Stata 11.0. The search strategy identified 1038 potentially relevant articles, seven of which were included in the final meta-analysis, covering a total of 1767 cases and 2785 controls. Overall, no significant association was found between TLR4 gene Asp299Gly polymorphism and ischemic cerebrovascular disease risk (for G allele versus A allele: OR = 0.95, 95% CI = 0.75-1.21, p = 0.69; for G/G+A/G versus A/A: OR = 0.96, 95% CI = 0.75-1.22, p = 0.73). In addition, the similar results were obtained in the sensitivity analysis based on studies with the high quality. In summary, the present meta-analysis indicates that TLR4 gene Asp299Gly polymorphism is not associated with increased ischemic cerebrovascular disease risk.

Influence of interleukin-6 gene -174G>C polymorphism on development of atherosclerosis: a meta-analysis of 50 studies involving 33,514 subjects.

Increasing epidemiological studies have focused on the associations between interleukin-6 (IL-6) gene -174G>C polymorphism and atherosclerotic diseases, but the results are still controversial. This meta-analysis was designed to identify whether this association exists. PubMed, Embase, Web of Science, Cochrane database, Clinicaltrials.gov and Current Controlled Trials, Chinese Clinical Trial Registry, CBMdisc, CNKI and Google Scholar were searched to get the genetic association studies. The crude odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) were used to estimate the association between the IL-6 gene -174G>C polymorphism and atherosclerosis ( AS ) risk. The subgroup analyses were made on the following: ethnicity, atherosclerotic diseases and source of controls. Finally, 50 studies (15,029 cases and 18,485 controls) were included in this meta-analysis. Overall, no significant association was found between the IL-6 gene -174G>C polymorphism and AS risk (for C allele vs. G allele: OR=1.02, 95% CI=0.94-1.11, p=0.64; for C/C vs. G/G: OR=1.01, 95% CI=0.85-1.21, p=0.88; for C/C vs. C/G+G/G: OR=0.97, 95% CI=0.84-1.12, p=0.68; for C/C+C/G vs. G/G: OR=1.07, 95% CI=0.97-1.17, p=0.18). In the subgroup analyses, significant associations were found between the IL-6 gene -174G>C polymorphism and AS in non-Caucasian group (for CC+CG vs. GG: OR=1.22, 95% CI=1.06-1.41, p=0.005), other atherosclerotic diseases group (for C allele vs. G allele: OR =0.75, 95% CI=0.61-0.93, p=0.008; for C/C vs. G/G: OR=0.56, 95% CI=0.38-0.81, p=0.002; for C/C vs. C/G+G/G: OR=0.60, 95% CI=0.45-0.79, p=0.0004) and population-based group (for C allele vs. G allele: OR=1.09, 95% CI=1.00-1.18, p=0.04; for CC+CG vs. GG: OR=1.15, 95% CI=1.04-1.27, p=0.005). In summary, the present meta-analysis suggests that the IL-6 gene -174G C polymorphism is associated with the susceptibility to AS. However, due to the high heterogeneity in the meta-analysis, the results should be interpreted with caution.

Lack of an association between CYP11B2 C-344T gene polymorphism and ischemic stroke: a meta-analysis of 7,710 subjects.

BACKGROUND: The association between aldosterone synthase (CYP11B2) C-344T gene polymorphism and ischemic stroke remains controversial and ambiguous. To better explain the association between CYP11B2 polymorphism and ischemic stroke risk, a meta-analysis was performed. METHODS: Based on comprehensive searches of Medline, Embase, Web of Science, CNKI and CBM databases, we identified and abstracted outcome data from all articles to evaluate the association between CYP11B2 polymorphism and ischemic stroke. The pooled odds ratios (ORs) with 95% confidence intervals (CIs) were performed in all genetic models. Fixed or random effects model was separately used depending on the heterogeneity between studies. Publication bias was tested by Begg's funnel plot and Egger's regression test. RESULTS: A total of 12 studies including 3,620 ischemic stroke cases and 4,090 controls were identified. There was no statistical evidence of association between CYP11B2 C-344T polymorphism and ischemic stroke in all genetic models (allelic model: OR = 1.19, 95% CI = 0.95-1.49; additive model: OR = 1.43, 95% CI = 0.91-2.27; dominant model: OR = 1.30, 95% CI = 0.89-1.89; and recessive model: OR = 1.24, 95% CI = 0.96-1.60). On subgroup analysis by ethnicity, similarly results were found in both Asians and non-Asians. For Asians, the combined ORs and 95% CIs were (allelic model: OR = 1.07, 95% CI = 0.87-1.32; additive model: OR = 1.15, 95% CI = 0.77-1.71; dominant model: OR = 1.13, 95% CI = 0.92-1.38; and recessive model: OR = 1.09, 95% CI = 0.84-1.40). For none-Asians, the combined ORs and 95% CIs were (allelic model: OR = 1.58, 95% CI = 0.90-2.76; additive model: OR = 2.37, 95% CI = 0.79-7.05; dominant model: OR = 1.79, 95% CI = 0.77-4.19; and recessive model: OR = 1.80, 95% CI = 0.96-3.36). CONCLUSION: The present meta-analysis suggested that CYP11B2 C-344T polymorphism was unlikely contribute to ischemic stroke susceptibility.