Phytoestrogens and risk of prostate cancer: an updated meta-analysis of epidemiologic studies.

This updated meta-analysis was performed to clarify the relationship between phytoestrogens and prostate cancer risk. Twenty one case-control and two cohort studies were finally selected for this meta-analysis, totaling 11,346 cases and 140,177 controls. Analytical results showed that daidzein (OR = 0.85; 95% CI: 0.75-0.96), genistein (OR = 0.87; 95% CI: 0.78-0.98), and glycitein (OR = 0.89; 95% CI: 0.81-0.98) were associated with a reduction of prostate cancer risk, but total isoflavones (OR = 0.93; 95% CI: 0.84-1.04), equol (OR = 0.86; 95% CI: 0.66-1.14), total lignans (OROgna.05; 95% CI: 0.54-2.04), secoisolariciresinol (OR = 1.02; 95% CI: 0.83-1.24), matairesinol (OR = 0.91; 95% CI: 0.75-1.11), enterolactone (OR = 0.94; 95% CI: 0.73-1.20), and coumestrol (OR = 0.89; 95% CI: 0.76-1.06) were not. Sensitivity and publication bias analyses demonstrated that the pooled estimates were stable and reliable. The results support the notion that some phytoestrogens may have a role in decreasing the risk of prostate cancer. Additional large and well-designed cohort studies are needed to confirm these relationships.

Polymorphism - 116C/G of the human X box binding protein 1 gene is associated with risk of type 2 diabetes in a Chinese Han population.

Evidence has been obtained showing that endoplasmic reticulum (ER) stress is closely associated with the development of type 2 diabetes (T2D) and that the human X box binding protein 1 (XBP1) is an important transcription factor involved in the development of ER stress. The study aimed to analyze the potential association between polymorphism -116C/G of XBP1 and the risk of T2D. The association between XBP1 polymorphism -116C/G and T2D risk was assessed among 1058 consecutive unrelated subjects, including 523 T2D patients and 535 healthy controls, in a case control study. The -116GG genotype and -116G allele were more frequent in T2D subjects compared with control subjects by statistical analysis, showing that the -116GG homozygote polymorphism of XBP1 might lead to increased susceptibility to T2D in a Chinese Han population. T2D subjects with the -116GG genotype had higher fasting plasma glucose levels, fasting insulin levels, and HbA1c and worse HOMA-IR than the T2D subjects with -116CG and -116CC genotypes (P<0.0001). The study supports a role for -116C/G polymorphism of the XBP1 promoter in the pathogenesis of T2D in a Chinese Han population, and more studies are needed to further evaluate our results.

Association between promoter polymorphisms of the GRP78 gene and risk of type 2 diabetes in a Chinese Han population.

There are large amounts of unfolding or misfolding protein accumulation in the endoplasmic reticulum in patients with type 2 diabetes (T2D), which in turn induces the expression of the glucose-regulated protein 78 (GRP78) that plays a key role in influencing insulin secretion and maintaining glucose homeostasis in pancreatic beta cells. The aim in the study is to analyze the potential association between single-nucleotide polymorphisms (SNPs) of GRP78 and the risk of T2D. To assess the association between GRP78 polymorphisms and T2D, a case-control study was conducted among 1058 consecutive unrelated subjects. Of the 1058 subjects, 523 of them were diagnosed with T2D and 535 of them were healthy controls. Four SNPs with R(2)>0.8 and the minor allele frequency>0.05 (rs391957, rs17840761, rs17840762, and rs11355458) in the GRP78 gene promoter were analyzed. Overall, no associations of GRP78 polymorphisms with T2D were observed in genotypic analyses. In addition, haplotypes combining those SNPs in the promoter in high linkage disequilibrium were also not associated with a T2D risk. However, the levels of fasting plasma glucose and HbA1c in patients with the -415AA/-180GG genotype were significantly lower than those of the patients with -415GG/-180deldel and -415AG/-180Gdel genotypes, and the level of fasting insulin in patients with the -415AA/-180GG genotype was significantly lower than that of the patients with -415GG/-180deldel. The study does not support a role for promoter polymorphisms of GRP78 in T2D in a Chinese Han population, but it does provide a clue for association between low levels of fasting plasma glucose, HbA1c and fasting insulin, and the -415AA/-180GG model.

A functional p.82G>S polymorphism in the RAGE gene is associated with multiple sclerosis in the Chinese population.

BACKGROUND: The receptor for advanced glycation end products (RAGE) and its proinflammatory ligand, S100-calgranulins, are critically implicated in the pathological progression of multiple sclerosis (MS). A functional polymorphism within the V-type immunoglobulin domain of RAGE gene, p.82G>S (c.557G>A), has been shown to affect ligand binding affinity and thus may affect susceptibility to MS. METHODS: The RAGE p.82G>S polymorphism was genotyped in 144 MS patients and 156 healthy controls using polymerase chain reaction - restriction fragment length polymorphism. A replication study was performed on a second cohort comprising 138 patients and 150 controls. The relationship between the RAGE p.82G>S polymorphism and circulating levels of soluble RAGE (sRAGE), a secreted decoy receptor against RAGE signaling, was also investigated. RESULTS: In both initial and replication cohorts, an increased MS risk was detected in RAGE p.82G>S variant allele carriers (odds ratio [OR] = 1.786, p = 0.0134 and OR = 1.732, p = 0.0210, respectively). This association signal persisted in subgroups of women and patients with relapsing-remitting MS. Moreover, compared with the wild-type 82GG carriers, carriers of the variant allele presented a faster progression of disability and a reduced serum sRAGE level. CONCLUSIONS: The present study provides preliminary evidence that the gain-of-function p.82G>S polymorphism in the RAGE gene is associated with an increased risk of MS in the Chinese population.

[Relationship between maximum body mass index and type 2 diabetes mellitus among adults in Heilongjiang province.].

OBJECTIVE: To determine the prevalence and distribution of type 2 diabetes mellitus (T2DM) and the relationship between maximum body mass index (MAXBMI) and T2DM. METHODS: From June to August, 2005, a stratified cluster sampling of 1071 permanent residents in communities, over 20 years old, from 4 districts and 1 county of Mudanjiang was chosen. The prevalence of T2DM, and the association between T2DM and different levels of the MAXBMI, current BMI were studied. RESULTS: The prevalence in the communities was 7.09% and in those with past maximum BMI >/= 28 kg/m(2), it was 12.10%. With the increase of past MAXBMI levels, the risk of T2DM patients also increased significantly (trend chi(2) = 17.387 23, P < 0.0001). Data from multifactor analysis showed that MAXBMI in the past was positively related to T2DM (OR = 3.06, P = 0.0013). In T2DM patients, the group with MAXBMI >/= 27.4 kg/m(2) had higher 2-hour postprandial blood glucose than those with lower MAXBMI (P = 0.0408). When compared with low maximum BMI group in normal blood glucose population, the group with higher MAXBMI (>/= 25.4 kg/m(2)) had higher blood glucose and greater change of BMI. CONCLUSION: In both groups that patients with T2DM and with normal glucose, in order to control blood glucose better, researchers should not only concern about the influence of the MAXBMI in the past, but also pay attention to constantly keep BMI at the normal range.

Knowledge and risk behaviors related to HIV/AIDS, and their association with information resource among men who have sex with men in Heilongjiang province, China.

BACKGROUND: In Heilongjiang province, the HIV prevalence in men who have sex with men (MSM) is generally lower than other part of China. However, the official perception for their risk of HIV/AIDS infection has been increasing in the province over the years. Moreover, little information on HIV/AIDS was provided to the communities so that we have disadvantage of controlling HIV/AIDS epidemic in the region. The purpose of this study is to investigate the prevalence of HIV among MSM in Heilongjiang province, to assess their knowledge levels and risk behaviors related to HIV/AIDS, and to explore their associations with information resources. METHODS: A cross-sectional study using a standardized questionnaire and blood test was administered in 2008 by local interviewers to a sample (1353) of MSM in four cities in Heilongjiang province. RESULTS: Among 1353 MSM, 2.3% were identified with HIV infection. About 48.7% of the subjects had multiple male sexual partners and only 37.3% of the subjects had consistent condom use (use every time) in the past 6 months. Most had a fair level of knowledge on HIV/AIDS, with the highest mean knowledge score among the MSM from Jiamusi, those with income 2000-3000 RMB/month, those searching sexual partners via internet and those performed HIV testing over 1 year ago). However, some myths regarding viral transmission (e.g., via mosquito bites or sharing kitchen utensils) also existed. Resources of information from which knowledge and risk behaviors related to HIV/AIDS was most available were television (58.6%) among MSM, followed by sexual partner (51.6%), publicity material (51.0%) and internet (48.7%). Significantly statistical differences of mean knowledge score were revealed in favor of book (P = 0.0002), medical staff (P = 0.0007), publicity material (P = 0.005) and sexual partner (P = 0.02). Press (P = 0.04) and book (P = 0.0003) were contributory to the most frequent condom use (condom use every time), while medical staff (P = 0.005) and publicity material (P = 0.04) is associated with moderate rate of condom use (condom use often). CONCLUSIONS: Although the prevalence of HIV infection is low among MSM in Heilongjiang province, the situation that the risk behaviors were frequent in the population is alarming. The study suggests that some strategies like condom use and education intervention are practical approaches and need to be strengthened.

Genetic polymorphisms of glutathione S-transferase T1 and bladder cancer risk: a meta-analysis.

In recent years, there have been numerous papers emphasizing the relationship between Glutathione S-transferases polymorphisms and bladder cancer risk, but the findings have not reached a consensus. The relationship between glutathione S-transferase T 1 null genotype and bladder cancer susceptibility is now even more disputable. Therefore, we present a meta-analysis of (nested) case-controlled, genotype-based studies (including 37 studies, 6,986 cases and 9,166 controls) examining this association. Using a fixed-effect model, statistically significant increase was observed between glutathione S-transferase T 1 deletion and bladder cancer risk for the overall studies (OR = 1.12; 95% confidence interval (CI): 1.04-1.21; P = 0.004 for Z test; I (2) = 47.43 for heterogeneity). After adjusting the result using trim-and-fill method, the outcome still had significant difference with little downgrade (OR = 1.10, 95% CI = 1.02-1.18). Three potential sources of heterogeneity including ethnicity, source of control and smoking status were also assessed. Minor increased correlation was found only in population-based studies (OR = 1.16; 95% CI = 1.03-1.30; I (2) = 47.16). Our analysis suggests that glutathione S-transferase T 1 null status is associated with a modest increase in the risk of bladder cancer and the difference exiting in source of control has been confirmed. Due to limited sample size, various confounding variables as well as discrepancy in study design, a valid conclusion still cannot be confirmed.

Association between the RAGE G82S polymorphism and Alzheimer's disease.

The receptor for advanced glycation end products (RAGE) is associated with several pathological states including Alzheimer's disease (AD) pathology, while its soluble form (sRAGE) acts as a decoy receptor. We have tested for association of AD with a functional single-nucleotide polymorphism (SNP) in the RAGE gene (G82S; rs2070600), a SNP associated with increased ligand affinity of RAGE. Analysis of a Chinese cohort (276 cases; 254 controls) showed a higher prevalence of the RAGE 82S allele and GS + SS genotype in the patients [82S vs. 82G: P = 0.017, odds ratio (OR) = 1.431; GS + SS vs. GG: P = 0.025, OR = 1.490]. Further stratification analysis revealed that the association of the RAGE G82S polymorphism with AD was significant in early onset AD stratum. Moreover, plasma sRAGE levels were lower in AD than in normal elderly controls, and the presence of the risk allele was associated with further plasma sRAGE reduction and a fast cognitive deterioration. The present study provides preliminary evidence that the RAGE G82S variant is involved in genetic susceptibility to AD.

Influence of the Pro12Ala polymorphism of PPAR-gamma on age at onset and sRAGE levels in Alzheimer's disease.

Peroxisome proliferator-activated receptor gamma (PPAR-gamma) has been described to have a role in the modulation of various genes involved in Abeta homeostasis, inflammation, and energy metabolism, making it a candidate gene for risk of Alzheimer's disease (AD). A functional polymorphism in exon 2 of the PPAR-gamma gene has been related to AD, but the effects are inconsistent across studies. To determine the role of PPAR-gamma in genetic susceptibility to AD in a representative Chinese sample, we genotyped 362 AD patients and 370 healthy controls for PPAR-gamma Pro12Ala polymorphism by polymerase chain reaction-restriction fragment length polymorphism method. We also examined the potential impact of this polymorphism on plasma level of soluble receptor for advanced glycation end products (sRAGE), a decoy receptor whose reduction has been associated with a higher risk of AD. Our results suggest that PPAR-gamma Pro12Ala polymorphism was not associated with an increased risk of AD in the overall sample. Stratification analysis revealed that the PPAR-gamma Pro/Ala genotype may be associated with the development of early-onset AD in the individuals without APOE epsilon4 allele (OR=3.76, 95% CI=1.10-12.84; p=0.03), but this association became insignificant after Bonferroni correction (p (corr)=0.10). Moreover, in the subgroup of APOE epsilon4 noncarriers, Kaplan-Meier survival analyses indicated that AD patients with the Pro/Ala genotype presented with disease onset 4.6 years earlier than carriers of Pro/Pro genotype. Further investigation revealed that AD patients carrying Pro/Ala genotype had significantly lower plasma sRAGE levels than patients with Pro/Pro genotype. These findings suggest that the functional PPAR-gamma Pro12Ala polymorphism may modify the age at onset of AD.

Genetic polymorphisms of interleukin 8 and risk of ulcerative colitis in the Chinese population.

BACKGROUND: Interleukin-8 (IL-8), a CXC chemokine that recruits and activates inflammatory cells, plays a critical role in the pathogenesis of ulcerative colitis (UC). There are no studies on the association of single nucleotide polymorphisms (SNPs) of the IL-8 gene with the risk of UC. METHODS: All 162 unrelated UC patients and 203 control subjects were analyzed for 5 IL-8 SNPs ((-845 (T/C), -738 (T/A), -353 (A/T), -251 (T/A) and +678 (T/C)) using polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) assay and PCR-sequence-specific primers (SSP) method. Serum IL-8 concentrations were measured in all subjects. RESULTS: Individual SNPs were not associated with risk for UC. However, the frequency of -353A/-251A/+678T haplotype was significantly higher in UC patients than in healthy controls (OR=1.454, p=0.036). By subgroup analyses, this haplotype tended to be more common in severe UC patients than in those with mild-to-moderate disease (OR=2.281, p=0.027). Furthermore, patients with AAT diplotype showed significantly increased serum IL-8 concentrations than those with other diplotypes (p<0.001). CONCLUSION: These results suggest that IL-8 is a novel susceptibility gene to UC in Chinese UC patients, and furthermore, that IL-8 polymorphisms may be related to severe clinical subtype of UC.

Interaction between interleukin-8 and methylenetetrahydrofolate reductase genes modulates Alzheimer's disease risk.

BACKGROUND/AIM: Interleukin-8 (IL-8), a potent chemoattractant for neutrophils, has been implicated in the pathogenesis of Alzheimer's disease (AD). The ability of individuals to produce high levels of IL-8 is partially determined by the IL-8 -251 T/A polymorphism. Therefore, we investigated the association between this polymorphism and AD in a Chinese population. Additionally, in light of the stimulatory effect of homocysteine on the production of IL-8, we also sought to determine whether the methylenetetrahydrofolate reductase (MTHFR) gene 677 C/T variant, a genetic modifier of the serum homocysteine level, may interact with the IL-8 -251 polymorphism in determining the AD risk. METHODS: Genotyping of 198 AD patients and 240 matched controls was performed by PCR-RFLP. RESULTS: The presence of the MTHFR 677 C/T and 677 T/T genotypes conferred a marginally significant increase in the risk for AD (OR = 1.666, 95% CI = 1.022-2.715, and OR = 1.892, 95% CI = 1.124-3.187) and the presence of the IL-8 -251 polymorphism was not associated with AD. However, the OR for AD associated with joint occurrence of the MTHFR 677 T/T and the IL-8 -251 A/A genotypes was 2.512 (95% CI = 1.151-5.483). CONCLUSION: Our data suggest a critical role for IL-8/MTHFR interactions in the development of AD.

Polymorphisms of the macrophage inflammatory protein 1 alpha and ApoE genes are associated with ulcerative colitis.

BACKGROUND AND AIMS: An increased production of macrophage inflammatory proteins 1 alpha (MIP-1alpha) has been reported to be associated with ulcerative colitis (UC). We investigated whether a polymorphism site in MIP-1alpha was associated with UC in a Chinese population. Additionally, considering the abnormal lipoprotein metabolism in subjects with UC, we also sought to determine whether genetic variation in the apolipoprotein E (ApoE) gene may play a role in the development of UC. MATERIALS AND METHODS: We examined the MIP-1alpha -906 (TA)(4)/(TA)(6) polymorphism and the ApoE polymorphism in a cohort of 162 unrelated UC patients and 220 healthy controls by using restriction fragment length polymorphism assay. RESULTS: A significantly increased frequency of the MIP-1alpha -906 (TA)(6)/(TA)(6) genotype (P = 0.0031, odds ratio [OR] = 1.851, 95% confidence interval [CI] 1.228-2.791), as well as of the ApoE epsilon4+ genotype (P < 0.001, OR = 2.869, 95% CI 1.768-4.657), in patients with UC was proven. Moreover, the carriage of both MIP-1alpha -906 (TA)(6)/(TA)(6) genotype and ApoE epsilon4+ genotype confers greater risk for the development of UC (P < 0.001, OR = 5.432, 95% CI 2.761-10.689). CONCLUSION: These findings suggest that variation in the MIP-1alpha and ApoE genes and their interaction may increase susceptibility to UC. Identifying these novel susceptibility genes, as well as their interactions, will help our understanding of the disease mechanisms of UC and may identify targets for developing novel treatment measures.