Association study between the −1021C/T polymorphism of the dopamine-β-hydroxylase gene promoter and personality traits in healthy subjects

Dopamine and norepinephrine are implicated in the characterization of personality traits. Dopamine-β-hydroxylase (DBH) is the enzyme responsible for conversion of dopamine to norepinephrine, and thus plays an important role in controlling dispositions of these neurotransmitters. Previous studies have shown that the −1021C/T polymorphism of the DBH gene promoter influences plasma DBH activity. Therefore, we examined the association between the −1021C/T DBH polymorphism and personality traits in 627 Japanese healthy volunteers. The DBH genotypes were identified by a PCR-RFLP method, and personality traits were assessed by the Temperament and Character Inventory (TCI). In the two-factor analysis of covariance with the DBH genotype and sex as factors and with age as a covariate, there was no main effect of the DBH genotype on any TCI score, while the interaction between the factors was significant in harm avoidance. In the post hoc analysis, the group with the T allele predictive of lower DBH activity had higher scores of harm avoidance than that without the T allele in females (p = 0.006), but not in males. The present study suggests that the −1021C/T DBH polymorphism affects the personality trait of harm avoidance in healthy females.     

Cortisol responses to emotional stress in men: association with a functional polymorphism in the 5HTR2C gene

The serotonin 5HTR2C receptor has been shown to mediate HPA axis activation during stress. We hypothesized that a functional polymorphism (rs6318) of the 5HTR2C gene would be associated with HPA axis response to a laboratory stress protocol. The present sample consisted of 41 men (22 African Americans, 19 Caucasians). We found that at rest men with the more active rs6318 Ser23 C allele had similar cortisol values compared to those with the less active Cys23 G allele. During laboratory stress, however, men with the Ser23 C allele exhibited the predicted significantly higher cortisol levels (p < 0.001), as well as larger increases in anger (p = 0.08) and depressive mood (p = 0.006) ratings, compared to the Cys23 G carriers. The increase in cortisol was significantly related to the increases in ratings of anger and depression assessed before and after the emotion induction, and these correlations became nonsignificant when rs6318 genotype was covaried. We conclude that genetic variation in 5HTR2C may be associated with HPA axis activation and stimulated by emotional stress, and also with both psychological and physiological endophenotypes that increase the risk of cardiovascular disease and type-2 diabetes.     

Associations between anterior cingulate cortex glutamate and γ-aminobutyric acid concentrations and the harm avoidance temperament

Converging lines of evidence have suggested that the personality traits might have neurobiological underpinnings. The anterior cingulate cortex (ACC) has been implicated to play an important role in the human fear and anxiety. Functional and structural characteristics of ACC have been suggested to be associated with the harm avoidance (HA) temperament, one of the important temperament dimensions. Therefore, we aimed to investigate correlations between neurometabolite concentrations in ACC, specifically glutamate and γ-aminobutyric acid (GABA), which are major excitatory and inhibitory neurotransmitters, respectively, and HA scores. Neurometabolite concentrations were measured using high resolution single voxel proton magnetic resonance spectroscopy (¹H-MRS), and the HA temperament was evaluated using the Temperament and Character Inventory (TCI). Correlations between HA scores from 37 participants (21 men/16 women, age of 30.3 ± 7.0) and glutamate and GABA concentrations in the mid-ACC region were evaluated. HA scores correlated negatively with glutamate concentrations in ACC (partial correlation, R = −0.54, df = 33, P = 0.001) and positively with GABA concentrations in ACC (partial correlation, R = 0.48, df = 30, P = 0.005). These findings suggest that glutamate and GABA concentrations in ACC are closely related to levels of the HA temperament in healthy subjects.     

Association between somatostatin gene polymorphisms and sporadic Alzheimer's disease in Chinese population

Recent evidence has suggested that down-regulation of somatostatin (SST) expression in the human brain during early stages of aging leads to an elevation in the steady-state levels of Aβ and therefore may be involved in Alzheimer's disease (AD) progression. We hypothesized that alterations in the SST gene might alter its expression or function and also play a role in the pathogenesis of sporadic AD (SAD). First, we sequenced the entire SST gene in 25 randomly selected controls and 25 SAD patients and then screened for C/T polymorphisms (rs4988514) in the 3′ un-translated region. We genotyped rs4988514 polymorphisms as well as apolipoprotein ?4 (APOE ?4) status in 309 SAD patients and 276 normal controls with restriction fragment length polymorphism (RFLP) analysis. Results showed that the C allele of the rs4988514 polymorphism had an increased incidence in the SAD group compared to the control group (p = 0.042). In subjects with the APOE ?4 allele, the presence of both the CC genotype and the C allele of this polymorphism were elevated in the SAD group compared to the control group (genotype p = 0.027, allele p = 0.011). In the whole study group, the age, sex, and APOE ?4 adjusted OR for the risk of AD in C allele carriers was 1.313 (95%CI = 1.068–2.234, p = 0.027) whereas within only APOE ?4 allele carriers, the adjusted OR increased to 2.734 (95%CI = 1.236–5.862, p = 0.012). Our results supported the notion that the C allele of the rs4988514 polymorphism may increase the risk for AD in the Chinese population and possibly have additive effect with the APOE ?4 allele.     

Association between interleukin-1β C (3953/4)T polymorphism and chronic periodontitis: Evidence from a meta-analysis

The aim of this study was to perform a meta-analysis to evaluated the association between interleukin-1β (IL-1β) C(3953/4)T polymorphism and chronic periodontitis (CP). Systematic searches of electronic databases and hand searching of references were performed, including PubMed, Embase and Web of Science. The pooled odds ratios (ORs) with 95% confidence intervals (95%CIs) were calculated. Publication bias was tested by Begg’s funnel plot and Egger’s regression test. Sensitivity analysis was conducted by limiting the meta-analysis studies conforming to Hardy–Weinberg equilibrium (HWE) or high quality (score ? 7). Data analyses were carried out by Stata 11.0. There were significant associations between IL-1β C(3953/4)T polymorphism and CP (for T allele vs. C allele: OR = 1.30, 95%CI = 1.05–1.60, p = 0.02; for T/T vs. C/C: OR = 1.66, 95%CI = 1.12–2.45, p = 0.01; for C/T + T/T vs. C/C: OR = 1.28, 95%CI = 0.99–1.65; and for T/T vs. C/T + C/C: OR = 1.62, 95%CI = 1.15–2.29, p = 0.006). When stratified by ethnicity, statistically significantly elevated risk was found for Caucasians, but not for Asians. When stratified by study design, evidences of significant association was observed between IL-1β C(3953/4)T polymorphism and CP in both population-based studies and hospital-based studies. This meta-analysis indicates that there is strong evidence for association between IL-1β C(3953/4)T polymorphism and CP.     

SNP/haplotype associations of CCR2 and CCR5 genes with severity of chagasic cardiomyopathy

Background

Chronic inflammation plays a major role in the tissue injury seen in the chronic chagasic cardiomyopathy. The CCR2 and CCR5 chemokine receptors are involved with the type of cellular infiltrate present in cardiac tissue and CCR5-gene variants were previously associated with this pathology.

Methods and results

This is a replication study in an independent cohort with larger sample size. Nine SNPs of CCR5 and CCR2 were typified to confirm the association previously found with Chagas disease. Evidence of association with severity was found for the A allele of rs1799864 of CCR2 (p_ad = 0.02; OR = 1.91, 95% CI = 1.10–3.30), the T allele of the rs1800024 of CCR5 (p_ad = 0.01; OR = 1.95, 95% CI = 1.13–3.38), and the HHF^∗2 haplotype (p = 0.03, OR = 1.65, 95% CI = 1.03–2.65). These results were replicated in the study combined with previous data. In this analysis it was replicated the allele T of rs2734648 (p_ad = 0.009, OR = 0.52, 95% CI = 0.32–0.85) with protection. In addition, the allele G of rs1800023 (p_ad = 0.043, OR = 0.61, 95% CI = 0.38–0.98), and the HHC haplotype (p = 0.004, OR = 0.62, 95% CI = 0.44–0.86) were also associated with protection. In contrast, the allele A of rs1799864 of CCR2 (p_ad = 0.009; OR = 1.90, 95% CI = 1.17–3.08); and the allele T of rs1800024 of CCR5 (p_ad = 0.005, OR = 1.98, 95% CI = 1.22–3.23) were associated with greater severity. No evidence of association between symptomatic and asymptomatic patients was observed.

Conclusions

These results confirm that variants of CCR5 and CCR2 genes and their haplotypes are associated with the severity but not with susceptibility to develop chagasic cardiomyopathy.     

Association between interleukin-8 gene −251 T/A polymorphism and the risk of peptic ulcer disease: A meta-analysis

It remains controversial regarding the association between interleukin-8 (IL-8) gene −251 T/A polymorphism and peptic ulcer disease (PUD) risk. Thus, a large-scale meta-analysis evaluating the precise association between this gene variant and PUD risk is required. We searched the PubMed, Embase, Web of Science, and Google Scholar until April 25, 2012. Additionally, hand searching of the references of identified articles were performed. All the statistical tests were performed using Stata 11.0. A total of eight studies (3105 subjects) were included in this meta-analysis. Overall, no significant association was found between IL-8 gene −251 T/A polymorphism and PUD risk (for A allele vs. T allele: OR = 1.17, 95% CI = 0.97–1.41, p = 0.094; for A/A vs. T/T: OR = 1.33, 95% CI = 0.94–1.90, p = 0.108; for A/A vs. A/T + T/T: OR = 1.22, 95% CI = 0.97–1.52, p = 0.083; for A/A + A/T vs. T/T: OR = 1.26, 95% CI = 0.95–1.67, p = 0.113). However, in the subgroup analyses by ethnicity, H. pylori infection and the subtype of PUD, significant associations were found between IL-8 gene −251 T/A polymorphism and PUD risk in Asians, H. pylori+, duodenal ulcer disease (DUD) and gastric ulcer disease (GUD), respectively. In summary, the present meta-analysis suggests that IL-8 gene −251 T/A polymorphism is associated with increased PUD risk among Asians, and especially for the subgroups of H. pylori+, DUD and GUD.     

Meta-analysis of FKBP5 gene polymorphisms association with treatment response in patients with mood disorders

The aim of our study was to assess the association between FKBP5 gene polymorphisms and treatment response in patients with mood disorders using a meta-analysis. Eight separate studies that included data from 2199 subjects were identified. Meta-analysis was performed for three FKBP5 gene polymorphisms (rs1360780, rs3800373, and rs4713916). A significant association of FKBP5 gene rs4713916 polymorphism and response rate was found in patients with mood disorders (Overall: A versus G: OR = 1.28, 95%CI = 1.06–1.53, P = 0.01; GA + AA versus GG: OR = 1.32, 95%CI = 1.05–1.67, P = 0.02. Caucasian: A versus G: OR = 1.28, 95%CI = 1.06–1.55, P = 0.01; GA + AA versus GG: OR = 1.33, 95%CI = 1.04–1.70, P = 0.02). However, we did not detect the association between FKBP5 gene rs1360780 and rs3800373 polymorphisms and treatment response in patients with mood disorders (P > 0.05). This meta-analysis demonstrates that treatment response in patients with mood disorders is associated with FKBP5 gene rs4713916 polymorphism, but not rs1360780 and rs3800373.     

Association between functional Fc receptor-like 3 (FCRL3) −169 C/T polymorphism and susceptibility to seropositive rheumatoid arthritis in Asians: A meta-analysis

Objective

The aim of this study was to determine whether the functional Fc receptor like-3 (FCRL3) −169 C/T polymorphism confers susceptibility to rheumatoid arthritis (RA).

Methods

A meta-analysis was conducted on the associations between the FCRL3 −169 C/T polymorphism and RA.

Results

A total of 17 comparison studies including 11,170 patients and 11,142 controls were considered in the meta-analysis. The meta-analysis showed no association between RA and the FCRL3 −169 C allele in study subjects (OR = 1.046, 95% CI = 0.997–1.098, p = 0.068). Stratification by ethnicity indicated an association between the FCRL3 −169 C allele and RA in Asians (OR = 1.101, 95% CI = 1.035–1.174, p = 0.002), but not in Europeans. Stratification of patients according to the presence of rheumatoid factor (RF) revealed a different significant association between the C allele and RA in RF-positive and RF-negative RA patients. Stratification by ethnicity indicated an association between the FCRL3 −169 C allele and RF-positive RA in Asians (OR = 1.093, 95% CI = 1.004–1.189, p = 0.040), but not in Europeans.

Conclusions

This meta-analysis demonstrates that the FCRL3 −169 C/T polymorphism may confer susceptibility to seropositive RA in Asians.     

Association between CTLA-4 polymorphisms and susceptibility to Celiac disease: A meta-analysis

Objective

The study explored whether cytotoxic T lymphocyte antigen-4 (CTLA-4) polymorphisms confer susceptibility to Celiac disease (CD).

Methods

A meta-analysis was conducted on the associations between the CTLA-4 CT60 A/G, +49 A/G, −318 C/T polymorphisms and CD using allele contrast, a recessive model, a dominant model, and homozygote contrast.

Results

Thirteen separate comparison studies were considered in the meta-analysis consisting of 5072 patients with CD and 13,462 controls. All subjects were Europeans. Meta-analysis of the CTLA-4 CT60 A/G polymorphism showed an association between CD and the CTLA-4 CT60 G allele in all subjects [Odds ratio (OR) = 1.160, 95% Confidence interval (CI) = 1.104–1.219, p < 1.0 × 10⁻⁹). Meta-analysis using the recessive model also revealed an association between CD and the CTLA-4CT60 GG genotype (OR = 1.331, 95% CI = 1.093–1.620, p = 0.004). Furthermore, analyses using the dominant model and homozygote contrast showed the same pattern as that shown by the CTLA-4CT60 G allele. Meta-analysis of the CTLA-4 +49 A/G polymorphism showed no association between CD and the CTLA-4 +49 G allele in all subjects (OR = 0.992, 95% CI = 0.872–1.129, p = 0.907). Meta-analysis using the recessive, dominant model, and homozygote contrast showed the same pattern as that shown by the CTLA-4 +49 Gallele. Meta-analysis of the CTLA-4 −318 C/T polymorphism showed no association between CD and the CTLA-4 −318 T allele in all subjects (OR = 1.018, 95% CI = 0.813–1.275, p = 0.877).

Conclusions

The CTLA-4 CT60 A/G polymorphism was associated with CD susceptibility, but no association was found between CTLA-4 +49 A/G and −318 C/T polymorphisms and CD in Europeans.     

Investigation of the dopamine D5 receptor gene (DRD5) in adult attention deficit hyperactivity disorder

Several lines of evidence from neuroimaging, pharmacology and genetics support the involvement of the dopaminergic system in the etiology of Attention Deficit Hyperactivity Disorder (ADHD). Previous candidate gene studies have investigated the association between a dinucleotide (CA)_n repeat polymorphism, located 18.5 kb from the start codon of the DRD5 gene, and ADHD. Association between the 148 bp allele and ADHD has been reported in some studies, however replication of the finding has not been consistent. We tested for an association between the (CA)_n repeat and adult ADHD in a sample comprised of 119 families with adult ADHD probands and 88 unrelated adult ADHD cases with a corresponding number of controls matched for age, ethnicity and sex. In the family sample we found a non-significant trend for association between the 148 bp allele and ADHD (Z = 1.91, p = 0.055). An excess of non-transmissions was detected for the 150 and 152 bp alleles (Z = −2.26, p = 0.023; Z = −2.20, p = 0.028). Quantitative analysis performed using the Brown Attention Deficit Disorder Scale (BADDS) showed association between the 150 bp allele and lower total score (p = 0.011), and lower effort (p = 0.008), activation (p = 0.008) and attention (p = 0.01) cluster scores. We did not replicate association findings in the case–control group, likely due to the lack of statistical power of this sample. Our findings add to the literature suggesting DRD5 (CA)_n repeat has a modest effect in modulating susceptibility to adult ADHD but further studies are required.     

Association between variation in the vesicular monoamine transporter 1 gene on chromosome 8p and anxiety-related personality traits

Vesicular monoamine transporters are involved in the presynaptic packaging of norepinephrine, dopamine and serotonin into storage vesicles. The vesicles release their content upon arrival of an action potential into the synaptic cleft. Dysregulation of monoaminergic neurotransmission has been long postulated to play a relevant role in the etiology of neuropsychiatric disorders. The gene encoding the vesicular monoamine transporter 1 (VMAT1/SLC18A1) maps to chromosome 8p21, a region where several linkage peaks overlap between schizophrenia, bipolar disorder and anxiety-related personality traits. In this study, we tested the hypothesis that the missence variation Thr136Ile in the VMAT1/SLC18A1 gene is associated with anxiety-related personality traits. We tested a total of 337 unrelated subjects of German descent (167 male, 170 female). All participants were carefully screened for psychiatric disorders. The self-report State–Trait Anxiety Inventory (STAI) was completed by all subjects. Genotypes were obtained for the Thr136Ile (rs1390938) variation in the VMAT1 gene for all subjects. Genotype effects on personality variables were computed with MANOVA including age as a co-variant and gender as independent factor (MANCOVA). Results show that STAI scores were significantly affected by genotype (F = 3.108; d.f. = 4,331; p = 0.015) and age (F = 7.233; d.f. = 2,331; p = 0.001) but not by gender. A gender-by-genotype effect was observed for both the STAI state (p = 0.052) and trait score (p = 0.035). Dissection of the group by gender and subsequent contrast analysis of the genotype effects performed within the female group showed significant results (STAI state: Thr/Ile vs. Ile/Ile: T = 4.408, p = 0.0004; STAI trait: Thr/Ile vs. Ile/Ile: T = 3.074, p = 0.009) but not in the male group. Our findings support the hypothesis that anxiety-related personality traits are associated with variation in the VMAT1/SLC18A1 gene.     

Novel allelic variants in the human serotonin transporter gene linked polymorphism (5-HTTLPR) among depressed patients with suicide attempt

A polymorphism in the serotonin transporter gene (5-HTTLPR) is being extensively studied for association with suicidal behavior. A new allelic variant within the 5-HTTLPR polymorphism was described but it has not been thoroughly analyzed in the recent literature. The SNP functional analysis demonstrated that the A variant of the L allele (L_A) produces high levels of mRNA and that the G variant (L_G) is equivalent to the S allele. Our aims were to compare the frequency of 5-HTTLPR alleles in 94 depressed patients who attempted suicide compared to 94 controls free of psychiatric disorder, including the embedded SNP rs25531. Using the biallelic classification, our sample contained 62 (33%) LL, 76 (40.4%) LS, and 50 (26.6%) SS individuals. Using the functional classification system, our sample contained 43 (22.5%) L’L’, 84 (44.7%) L'S’, and 61 (32.4%) S'S’ individuals, with no significant differences between cases and controls in genotypic tests in either biallelic (χ² = 2.543; df = 2; p = 0.280) and functional models (χ² = 2.995; df = 2; p = 0.228). The minor allele frequency (MAF) – the S allele – did not show any distributional difference between cases and controls using biallelic classification system 0.51 vs. 0.43, (OR = 1.41; CI95% 0.94 to 2.12; p = 0.121). Also the S’ allele of the functional classification system did not show any distributional difference between the two groups 0.59. vs. 0.51 (OR = 1.35; CI95% 0.90 to 2.03; p = 0.178). This study provided the possibility of a re-analysis of novell 5-HTTLPR functional variants identified within L allele that alters its mRNA production and thus changes its functionality. We could not find any association between both biallelic and functional 5-HTTLPR in depressed patients with suicide attempt, being the small sample size an important limitation for these results. In conclusion, we can suggest that despite the several studies in this issue, the exact effect and role of 5-HTTLPR in genetics of suicide is still unclear and should be better investigated for future studies.     

Associations between interleukin 1 polymorphisms and susceptibility to systemic lupus erythematosus: A meta-analysis

Objective

This study determined whether interleukin 1 (IL1) polymorphisms are associated with susceptibility to systemic lupus erythematosus (SLE).

Methods

A meta-analysis was conducted on the associations between the IL1A, IL1B, and IL1 receptor antagonist (IL1RN) polymorphisms and SLE.

Results

A total of 15 studies involving 1956 SLE cases and 2347 controls were included in the meta-analysis. The meta-analysis showed an association between SLE and the IL1A −889 T allele in the overall population and Europeans (OR = 0.858, 95% CI = 0.737–0.986, p = 0.032; OR = 0.827, 95% CI = 0.687–0.994, p = 0.043). Meta-analysis of the IL1RN polymorphism revealed an association with SLE in all study subjects (OR for IL1RN^∗2 = 1.539, 95% CI = 1.266–1.871, p = 1.5 × 10⁻²) and in Europeans and Asians (OR = 1.483, 95% CI = 1.187–1.852, p = 0.001; OR = 1.787, 95% CI = 1.167–2.736, p = 0.008). No associations were found between SLE and the IL1B −511 C/T, 3953 C/T, and IL1A +4845 G/T polymorphisms.

Conclusions

This meta-analysis suggests IL1A −889 C/T polymorphism is associated with susceptibility to SLE in Europeans, and that the IL1RN^∗2 allele is associated with susceptibility to SLE in Europeans and Asians.     

Vitamin D receptor gene polymorphism and its association with Parkinson's disease in Chinese Han population

Vitamin D plays an important role in neurodegenerative disorders as a crucial neuro-immunomodulator, and accumulating data have provided evidence for that vitamin D receptor (VDR) gene is a candidate gene for susceptibility to Parkinson's disease (PD). In this study, we performed a case-control study to demonstrate whether the risk for the development of onset of sporadic PD might be influenced by VDR gene polymorphisms in a Chinese cohort. Two hundred and sixty PD patients and 282 matched-healthy controls were genotyped for two representative single nucleotide polymorphisms (SNPs) in VDR gene (FokI C/T and BsmI G/A) by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) analysis in. Results from our study revealed that FokI C allele carriers were likely to associate with an increased risk of PD (P = 0.004) as well as early-onset PD (EOPD) (P = 0.010). Moreover, the frequency of FokI C allele was significantly increased in PD group and late-onset PD (LOPD) group relative to the control groups respectively (P = 0.023 and P = 0.033, respectively). For BsmI polymorphisms, no significant difference in genotype or allele distribution was found between PD patients and the controls, as well as gender- and age-related differences between PD patients and the controls subgroup. This study demonstrated a possible association between the VDR FokI T/C polymorphism and PD, indicating that VDR polymorphisms may well change genetic susceptibility to sporadic PD in a Han Chinese population.     

Facilitating actions of an AMPA receptor potentiator upon extinction of contextually conditioned fear response in stressed mice

Mounting evidence supports the association between a polymorphism in the serotonin transporter gene promoter region (5-HTTLPR) and suicidal behaviour. Recently, a novel variant of the 5-HTTLPR L allele was identified. The previously unknown L_G allele produced similar levels of gene expression to the S allele and might have been misclassified as a “high-expression” allele in previous association studies. In this study, we aimed to compare the genotype distribution of the tri-allelic 5-HTTLPR polymorphism in 168 Chinese patients with schizophrenia, including 60 suicide attempters and 108 non-suicide attempters. In our analysis, which used the L_A dominant model, it was found that the L_A allele carriers were significantly more likely to have attempted suicide (p = 0.035). Further analysis showed this association existed only in male patients (p = 0.012). A similar association between the L_A allele and violent suicide attempt was also found (p = 0.028). In addition, logistic regression confirmed our findings that male L_A allele carriers were at a higher risk of suicide, although the lack of a significant association in females may reflect insufficient power due to small sample size. However, no association was found when we examined the traditional bi-allelic 5-HTTLPR. These findings differ from those reported in Caucasian subjects, where no associations have been reported. Different genetic backgrounds may give rise to different allelic distribution, causing differential effects on the expression of endophenotypes of suicide behaviours. Although the potential influence of multiple comparisons might weaken our findings, our study provides preliminary evidence for a potentially gender-specific role of a “high-expression” 5-HTTLPR polymorphism in susceptibility to suicide in Chinese patients with schizophrenia.     

High frequency of the IL-2 −330 T/HLA-DRB1*1501 haplotype in patients with multiple sclerosis

We have evaluated the role of the HLA-DRB1*1501 allele and the IL-2 −330 T/G polymorphism and their interaction in susceptibility to multiple sclerosis on 360 patients and 426 matched healthy individuals. We used the SSP-PCR method to determine the alleles. Fisher's exact test was used to analyses. We observed a significant increase in the T allele at IL-2 −330 position in patients (OR = 1.34, P < 0.05), and the T/T and T/G genotypes were more frequent among patients than controls. The HLA-DRB1*1501 allele was overrepresented in patients as compared to the control group (OR = 1.7, P = 0.0006). The two-locus analysis of the interaction between the IL-2 promoter polymorphism and the HLA-DRB1 allele showed that the HLA-DRB1*1501/T haplotype was more frequent in patients than controls (OR = 16, P < 0.0001). Our findings support previous findings about the role of the HLA-DRB1*1501 allele in susceptibility to MS. This work also provides new findings about the importance of gene–gene interactions in the development of MS.     

Hyperactivity of the HPA axis is related to dietary restraint in normal weight women

The objective of our study was to investigate the relationship between hypothalamus/pituitary/adrenal (HPA) axis functioning and dietary restraint in normal weight (BMI between 20 and 25 kg/m²) men and women. We therefore assessed in 38 men and 38 women HPA axis functioning, through measuring 5-hour cortisol exposure and cortisol feedback functioning through a dexamethasone (4 mg) suppression test. Eating behavior was assessed through the Three Factor Eating Questionnaire and body composition through hydro densitometry and deuterium dilution method. No relationship between HPA axis functioning and dietary restraint was found in men. Normal weight women with a restraint score ≥ 9 showed increased cortisol concentrations over a 5-hour time period, increased cortisol concentrations after a dexamethasone (4 mg) suppression test, higher BMI, and higher body fat percentage, when compared to women with a restraint score < 9. Moreover, a positive relationship was found between cortisol concentrations over a 5-hour time period and dietary restraint in combination with the disinhibition score (R² = 0.23, p < 0.001). We conclude that in normal weight women hyperactivity of the HPA-axis is related to dietary restraint especially in combination with disinhibition.     

Toll-like receptor 4 gene Asp299Gly polymorphism in myocardial infarction: A meta-analysis of 15,148 subjects

It remains controversial regarding the association between toll-like receptor 4 (TLR4) gene Asp299Gly (+896 A/G) polymorphism and myocardial infarction (MI) risk. Thus, a large-scale meta-analysis evaluating the potential association between this gene variant and MI risk is required. PubMed, Embase, Web of Science, CBMdisc, CNKI, and Google Scholar were searched until February 6, 2013. All the statistical tests were performed using Stata 11.0. Nine articles involving 10 studies were included in the final meta-analysis, covering a total of 8299 MI cases and 6849 controls. Overall, no significant association was found between the TLR4 gene Asp299Gly polymorphism and MI risk (G allele vs. A allele: OR = 0.95, 95% CI = 0.74–1.22, p = 0.71; G/G vs. A/A: OR = 1.03, 95% CI = 0.54–1.98, p = 0.93; G/G vs. A/G + A/A: OR = 1.05, 95% CI = 0.55–2.03, p = 0.87; G/G + A/G vs. A/A: OR = 0.92, 95% CI = 0.75–1.13, p = 0.42). In the subgroup analysis based on source of controls, there was also lack of evidence for significant association between the TLR4 gene Asp299Gly polymorphism and MI risk. In summary, the present meta-analysis indicated that the TLR4 gene Asp299Gly polymorphism was not associated with MI risk.