VDR Gene Polymorphisms and Cluster Headache Susceptibility: Case-Control Study in a Southeastern European Caucasian Population

Genomics and pharmacogenomics of cluster headache: implications for personalized management? A systematic review

The role of genetic factors in cluster headache etiology, suggested by familial and twin studies, remains ill-defined, with the exact pathophysiological mechanisms still largely elusive. This systematic review aims to synthesize current knowledge on cluster headache genetics and explore its implications for personalized treatment and prediction of treatment response. Thus, we searched PubMed, Scopus, and the Cochrane Library databases and reference lists of identified research articles, meta-analyses, and reviews to identify relevant studies up to 10 July 2024. The quality of the evidence was assessed using Newcastle-Ottawa Scale for case control studies and NIH Quality Assessment tool for Observational Cohort and Cross-Sectional Studies. The protocol of this study was registered via the Open Science Framework (https://osf.io/cd4s3). Fifty-one studies were selected for the qualitative synthesis: 34 candidate gene studies, 5 GWAS, 7 gene expression studies, 4 pharmacogenetic association studies, and 1 whole genome sequencing study. The bulk of genetic evidence in cluster headache underscores the involvement of genes associated with chronobiological regulation. The most studied gene in cluster headache is the HCRTR2, which is expressed in the hypothalamus; however, findings across studies continue to be inconclusive. Recent GWAS have uncovered novel risk loci for cluster headache, marking a significant advancement for the field. Nevertheless, there remains a need to investigate various genes involved in specific mechanisms and pathways.

The impact of genetic factors on the response to migraine therapy

Migraine is a multidimensional disease affecting a large portion of the human population presenting with a variety of symptoms. In the era of personalized medicine, successful migraine treatment presents a challenge, as several studies have shown the impact of a patient's genetic profile on therapy response. However, with the emergence of contemporary treatment options, there is promise for improved outcomes. A literature search was conducted in PubMed and Scopus, in order to obtain studies investigating the impact of genetic factors on migraine therapy outcome. Overall, 23 studies were included in the current review, exhibiting diversity in the treatments used and the genetic variants investigated. Divergent genes were assessed for each category of migraine treatment. Several genetic factors were identified to contribute to the heterogeneous response to treatment. SNPs related to pharmacodynamic receptors, pharmacogenetics and migraine susceptibility loci were the most investigated variants, revealing some interesting significant results. To date, various associations have been recorded correlating the impact of genetic factors on migraine treatment responses. More extensive research needs to take place with the aim of shedding light on the labyrinthine effects of genetic variations on migraine treatment, and, consequently, these findings can promptly affect migraine treatment and improve migraine patients' life quality in the vision of precise medicine.

The Prevalence and Clinical Phenotypes of Cluster Headache in Relation with Latitude

PURPOSE OF REVIEW

Previous studies have indicated a possible link between the prevalence of cluster headache (CH) and sunlight exposure. However, this theory has yet to be tested systemically. In this article, we aim to examine how latitude affects the prevalence and phenotypes of CH.

RECENT FINDINGS

To our knowledge, there is by far no article describing the effect of latitude on disease phenotype; thus, we performed a literature review. We noted positive effects of latitude on 1-year prevalence, the proportion of chronic CH, and the proportion of miosis and/or ptosis. Latitude may affect the phenotypic presentations of cluster headache, probably partially mediated via temperature and sunlight variations. Still, other factors, such as environmental exposure to smoking and the genetic difference between the Eastern and Western populations, may participate in the pathogenesis and clinical manifestations of CH.

Exploring the Potential Consortium of Migraine and Periodontitis

Objectives

Various researches have shown periodontitis to share common pathophysiological pathways with systemic diseases such as diabetes, cardiovascular diseases, and osteoporosis and recently neurological disorders. This article provides a narrative review summarizing the various linking mechanisms and the nature of association between two multifactorial diseases-periodontitis and migraine.

Materials and Methods

A literature search was performed for articles related to periodontitis and migraine up till the year 2023 which yielded totally 14 articles. There were only three randomized controlled clinical trials; therefore, we were unable to conduct a systematic review and focused on a narrative review. The keywords searched were "migraine", "periodontitis" and "biomarkers" in PubMed/Medline, Web of Science, and Embase databases. Any article related to the association of periodontitis and migraine and the dental management of subjects with headache disorders were included and studies with migraine and other dental diseases were excluded.

Results

It is found that the occurrence of periodontitis and migraine are associated with each other. There is reasonable evidence to believe that periodontitis and migraine are linked by direct and indirect mechanisms which can eventually lead to chronic inflammatory conditions like periodontitis worsening neurovascular conditions such as migraine. However, upon detailed analysis it was found that the strength of association is weak owing to the presences of various common confounding and risk factors.

Conclusions

The association between periodontitis and migraine cannot be denied, however, not all the criteria are fulfilled while examining the nature of association and future long-term studies are required to prove the same. Clinical Relevance. Various studies have reported poor periodontal health in patients with migraine. The risk of exacerbation of migraine also increases in subject undergoing dental therapy if the triggering factors are manipulated. Hence, knowing the precise pathophysiologic mechanisms linking both the diseases would be favorable in planning treatment protocols for subjects with migraine.

Genetic Variability in Vitamin D Receptor and Migraine Susceptibility: A Southeastern European Case-Control Study

Migraine is a common primary headache disorder with both environmental and genetic inputs. Cumulative evidence indicates an association between vitamin D and headache. Unravelling the precise role of vitamin D and its receptor in the pathophysiology of migraine can eventually contribute to more efficient prevention and management of this headache disorder. The aim of the study was to investigate the relation of the three most studied VDR variants, i.e., FokI (rs2228570), TaqI (rs731236) and BsmI (rs1544410), with migraine susceptibility and distinct clinical phenotypes in a Southeastern European case-control population residing in Greece. DNA was extracted from 191 unrelated patients diagnosed with migraine and 265 headache-free controls and genotyped using real-time PCR (LightSNiP assays) followed by melting curve analysis. Genotype frequency distribution analysis of the TaqI and BsmI variants showed a statistically significant difference between migraine cases and controls. In addition, subgroup analyses revealed a significant association between all three studied VDR variants, particularly with a migraine without aura subtype. Therefore, the current study provides supporting evidence for a possible association of VDR variants with migraines, particularly migraine without aura susceptibility in Southeastern Europeans residing in Greece, further reinforcing the emerging role of vitamin D and its receptor in migraines.

Investigating Vitamin D Receptor Genetic Markers in a Cluster Headache Meta-Analysis

Patients diagnosed with the primary headache disorder known as cluster headache (CH) commonly report that their headache attacks occur in patterns of both circadian and seasonal rhythmicity. Vitamin D is essential for a variety of bodily functions and vitamin D levels are largely regulated by daylight exposure in connection with seasonal variation. For this Sweden-based study, the association between CH and three single-nucleotide polymorphisms in the vitamin D receptor gene, rs2228570, rs1544410, and rs731236, were investigated, as well as CH bouts and trigger factors in relation to seasonal and weather changes. Over 600 study participants with CH and 600 controls were genotyped for rs2228570, and genotyping results for rs1544410 and rs731236 were obtained from a previous genome-wide association study. The genotyping results were combined in a meta-analysis, with data from a Greek study. No significant association was found between rs2228570 and CH or the CH subtype in Sweden, nor did the meta-analysis show significant results for any of the three markers. The most common period of the year to experience CH bouts in Sweden was autumn, and conditions linked to weather or weather changes were also identified as potential triggers for CH bouts for a quarter of the responders who reported bout triggers. Though we cannot rule out vitamin D involvement in CH, this study does not indicate any connection between CH and the three vitamin D receptor gene markers.

Headache in Workers: A Matched Case-Control Study

A case−control study including 446 workers reporting headaches (cases; 136 males and 310 females, mean age 46.71 ± 10.84 years) and 446 age- and sex-matched colleagues without headaches (controls; mean age 45.44 ± 10.13) was conducted in the second half of 2020 in a sample drawn from socio health and commercial services companies to investigate the association of headache with lifestyle, metabolic, and work-related factors. Workers suffering from headache reported higher body weight (OR: 1.92, 95% CI: 1.46−2.53, p < 0.001), higher blood cholesterol (OR: 2.01, 95% CI: 1.46−2.77, p < 0.001), triglyceride (OR: 2.01, 95% CI: 1.20−3.35, p < 0.01), blood glucose (OR: 1.91, 95% CI: 1.16−3.24, p < 0.01), and blood pressure levels (OR: 1.76, 95% CI: 1.23−2.52, p < 0.01). In the year preceding the survey, cases had experienced a higher frequency of workplace violence (OR: 2.29, 95% CI: 1.25−4.20, p < 0.01 for physical aggression, OR: 2.22, 95% CI: 1.45−3.41, p < 0.001 for threat, OR: 2.74, 95% CI: 1.72−4.38, p < 0.001 for harassment) and were more frequently distressed (effort/reward ratio > 1) (OR: 1.82, 95% CI: 1.39−2.40, p < 0.001) than the controls. Compared to the controls, cases also had higher scores on anxiety and depression scales, lower scores on happiness, and lower levels of sleep quality (p < 0.001). The association of headaches with metabolic and mental health problems suggests that monitoring headaches in the workplace could help to identify workers at risk of impairment.

Deciphering the Role of the rs2651899, rs10166942, and rs11172113 Polymorphisms in Migraine: A Meta-Analysis

The genetic basis of migraine is rather complex. The rs2651899 in the PR/SET domain 16 (PRDM16) gene, the rs10166942 near the transient receptor potential cation channel subfamily M member 8 (TRPM8) gene, and the rs11172113 in the LDL receptor-related protein 1 (LRP1) gene, have been associated with migraine in a genome-wide association study (GWAS). However, data from subsequent studies examining the role of these variants and their relationship with migraine remain inconclusive. The aim of the present study was to meta-analyze the published data assessing the role of these polymorphisms in migraine, migraine with aura (MA), and migraine without aura (MO). We performed a search in the PubMed, Scopus, Web of Science, and Public Health Genomics and Precision Health Knowledge Base (v7.7) databases. In total, eight, six, and six studies were included in the quantitative analysis, for the rs2651899, rs10166942, and rs11172113, respectively. Cochran’s Q and I2 tests were used to calculate the heterogeneity. The random effects (RE) model was applied when high heterogeneity was observed; otherwise, the fixed effects (FE) model was applied. The odds ratios (ORs) and the respective 95% confidence intervals (CIs) were calculated to estimate the effect of each variant on migraine. Funnel plots were created to graphically assess publication bias. A significant association was revealed for the CC genotype of the rs2651899, with the overall migraine group (RE model OR: 1.32; 95% CI: 1.02−1.73; p-value = 0.04) and the MA subgroup (FE model OR: 1.40; 95% CI: 1.12−1.74; p-value = 0.003). The rs10166942 CT genotype was associated with increased migraine risk (FE model OR: 1.36; 95% CI: 1.18−1.57; p-value < 0.0001) and increased MO risk (FE model OR: 1.41; 95% CI: 1.17−1.69; p-value = 0.0003). No association was detected for the rs11172113. The rs2651899 and the rs10166942 have an effect on migraine. Larger studies are needed to dissect the role of these variants in migraine.

Association of vitamin D receptor gene TaqI polymorphism with Alzheimer's disease in a Southeastern European Caucasian population

The role of vitamin D in Alzheimer's Disease (AD) has been studied over the past years. The results from numerous studies have indicated that the molecular pathways involved in the development of AD are closely related to the molecular pathways of the mechanisms of action of vitamin D. However, only a limited number of studies have described the key role of vitamin D receptor (VDR) in the regulation of the functions of vitamin D and the potential effect of single nucleotide polymorphisms (SNPs) of the VDR gene. Thus, the aim of the present study was to investigate the VDR TaqI polymorphism in relation to AD in a Southeastern European Caucasian (SEC) cohort. Further, the present study aimed to compare the results obtained with those of other AD populations. For this purpose, blood samples from 90 confirmed patients with AD [median age, 74 years; median mini-mental state examination (MMSE) score of 21; median frontal assessment battery (FAB) score of 10] and 103 healthy controls (median age, 57 years) were analyzed to determine the genotypes of TaqI (rs731236) using quantitative PCR. The frequencies (%) of the TaqI TT, TC and CC genotypes in the controls/patients were 34/48.9, 47.6/41.1 and 18.4/10.0, respectively. Statistically significant differences were observed for the TaqI C allele [odds ratio (OR). 0.54; 95% confidence interval (CI), 0.30-0.96; P=0.035], the TaqI TT genotype (OR, 1.86; 95% CI, 1.04-3.32; P=0.035) and the TaqI CC genotype (OR, 0.119; 95% CI, 0.014-0.995; P=0.032,) in relation to the MMSE score <21 in the patient's group. The TaqI TT allele was found to increase the risk of developing AD by 1.86-fold in the SEC population, while the TaqI C allele may act protectively, with a 46% lower risk of developing the disease. Patients with the TaqI CC genotype were found to have an 88% less likelihood of developing severe cognitive impairment based on the MMSE score. On the whole, the present study did not confirm the results of previous studies on the VDR TaqI C allele in patients with AD.

Vitamin D Supplementation and Genetic Polymorphisms Impact on Weight Loss Diet Outcomes in Caucasians: A Randomized Double-Blind Placebo-Controlled Clinical Study

Vitamin D deficiency or insufficiency is common in obese people, with some studies suggesting that low vitamin D level might be an independent predictor of obesity. Thus, the purpose of the present randomized, double-blind, placebo-controlled study was to investigate the effect of oral spray vitamin D₃ 3000 IU supplementation along with personalized weight-loss diet on obesity markers in overweight and obese Caucasians with vitamin d deficiency or insufficiency. The impact of vitamin D receptor (VDR) and adrenergic receptors (ADRs) genetic variants on vitamin D levels and weight loss diet outcomes was also investigated. After signing informed consent, a total of 125 eligible volunteers were randomly assigned into vitamin D (vitamin D₃ 3000 IU/d oral spray supplementation, n = 76) or placebo (xylitol, water, mint, n = 49) group following a weight loss program (600 calories less than the total energy expenditure of each volunteer) for 3 months. Fat mass, BMI, REE and 25(OH)D serum level were monitored on baseline and each month. DNA samples were extracted from buccal swabs and genotyped for the rs2228570 (VDR), rs1544410 (VDR), rs731236 (VDR), rs1800544 (ADRA2A), rs1801252 (ADRB1), rs1042713 (ADRB2), and rs4994 (ADRB3) polymorphisms. Statistical analysis was performed using SPSS package (v.23). Between group comparisons revealed significant improvement in serum 25(OH)D level and greater reduction in weight, BMI and fat percentage in the vitamin D group compared to placebo group (p < 0.05). In the vitamin D group, carriers of the rs2228570 T allele tended to have greater vitamin D level improvement compared with the homozygous C allele (p = 0.067). Furthermore, heterozygous (CT) for the rs731236 tended to have lesser weight loss (p = 0.068) and for the rs1042713, a lower decline in fat percentage was observed for homozygous AA carriers compared to the heterozygous (p = 0.051). In the control group, differences in weight loss (p = 0.055) and BMI (p = 0.045) were observed between rs1544410 AA and GG homozygous. In conclusion, vitamin D oral spray supplementation seems to improve vitamin D status and decrease obesity markers during a weight-loss intervention in overweight/obese Caucasians with vitamin D deficiency or insufficiency. Also, the results of the present study indicate that VDR and ADRs genetic polymorphisms seem to influence vitamin D supplementation response and obesity markers.