Migraine Genetic Variants Influence Cerebral Blood Flow.

OBJECTIVE: To investigate the association of migraine genetic variants with cerebral blood flow (CBF). BACKGROUND: Migraine is a common disorder with many genetic and non-genetic factors affecting its occurrence. The exact pathophysiological mechanisms underlying the disease remain unclear, but are known to involve hemodynamic and vascular disruptions. Recent genome-wide association studies have identified 44 genetic variants in 38 genetic loci that affect the risk of migraine, which provide the opportunity to further disentangle these mechanisms. METHODS: We included 4665 participants of the population-based Rotterdam Study (mean age 65.0 ± 10.9 years, 55.6% women). Cross-sectional area (mm2 ), flow velocity (mm/s), and blood flow (mL/min) were measured in both carotids and the basilar artery using 2-dimensional phase-contrast magnetic resonance imaging. We analyzed 43 previously identified migraine variants separately and calculated a genetic risk score (GRS). To assess the association with CBF, we used linear regression models adjusted for age, sex, and total brain volume. Hierarchical clustering was performed based on the associations with CBF measures and tissue enrichment. RESULTS: The rs67338227 risk allele was associated with higher flow velocity and smaller cross-sectional area in the carotids (Pminimum  = 3.7 × 10-8 ). Other variants were related to CBF with opposite directions of effect, but not significantly after multiple testing adjustments (P < 1.4 × 10-4 ). The migraine GRS was not associated with CBF after multiple testing corrections. Migraine risk variants were found to be enriched for flow in the basilar artery (λ = 2.39). CONCLUSIONS: These findings show that genetic migraine risk is complexly associated with alterations in cerebral hemodynamics.

High-density lipoprotein, low-density lipoprotein and triglyceride levels and upper gastrointestinal cancers risk: a trans-ancestry Mendelian randomization study.

OBJECTIVE: This study was conducted to explore the causal associations of high-density lipoprotein (HDL), low-density lipoprotein (LDL) and triglyceride (TG) with the risk of upper gastrointestinal cancers (esophageal cancer [EC] and gastric cancer [GC]). METHODS: A total of 5623 Chinese and 4133 Europeans afforded the individual-level genotyping data, and 203,608 Japanese from Biobank Japan project and 393,926 Europeans from UK Biobank supported summary statistics of cancer genetic associations. Mendelian randomization (MR) analyses, including weighted genetic risk scores (wGRSs), inverse-variance weighted (IVW), weighted median and Egger-regression, were utilized to evaluate the causal effects of three blood lipids on upper gastrointestinal cancers risk. RESULTS: There was no significantly causal relationships between three blood lipids and EC or GC risk among Chinese or Europeans but a potential causal association between TG and GC risk among Japanese (IVW: odds ratio [OR] = 1.11, P = 0.034; Phet = 0.679). In stratified subgroups, higher genetically predicted TG levels were causally associated with an increased risk of GC among Chinese males (wGRS: OR = 1.61, P = 0.021; IVW: OR = 1.57, P = 0.009; Phet = 0.653) and Japanese females (IVW: OR = 1.33, P = 0.024; Phet = 0.378). CONCLUSION: This trans-ancestry MR study suggested null significant causality between serum HDL, LDL or TG and the risk of upper gastrointestinal cancers among Chinese and Europeans, but provided evidence for a causal role of TG involved in GC etiology in Japanese (especially females), which would support a prevention guide for high-risk groups of GC. Further research with more comprehensive information is needed to explore the underlying mechanism.

Prediagnostic adult body mass index change and esophageal adenocarcinoma survival.

BACKGROUND: We examined whether body mass index (BMI) changes in adulthood, prior to disease onset, are associated with overall survival among esophageal adenocarcinoma patients. METHODS: We included 285 histologically confirmed patients with a complete baseline BMI questionnaire. Using extended Cox regression models, we obtained adjusted hazard ratios (HRs) for the associations between overall survival and BMI at diagnosis, BMI 6 months before diagnosis, self-reported average adult BMI, and ΔBMI (BMI 6 months before diagnosis minus average adult BMI), categorized into tertiles <0 kg/m2 (BMI loss), ≥0 and <1.25 kg/m2 (stable BMI), and ≥1.25 kg/m2 (BMI gain). We also assessed interaction between ΔBMI and average adult BMI (≥ kg/m2 versus <27.5 kg/m2 ) with overall survival. RESULTS: Body mass index at diagnosis >25 and <35 kg/m2 was associated with better overall survival. Compared to patients with stable BMI in adulthood, patients who gained BMI throughout adulthood had 1.68 times the all-cause hazard of death (95% CI: 1.17-2.43; P < .01), independent of diagnosis BMI and percent weight loss 6 months before diagnosis. Compared to patients with average adult BMI < 27.5 who maintained stable adult BMI, patients with average adult BMI ≥ 27.5 kg/m2 who gained BMI had the worst survival (HR = 3.05; 95% CI 1.62-5.72; P < .01). CONCLUSION: Body mass index gain in adulthood is associated with poor overall survival, and maintaining a normal body weight throughout adulthood is associated with the best overall survival among esophageal adenocarcinoma patients, independent of BMI at diagnosis.

The bidirectional association between reduced cerebral blood flow and brain atrophy in the general population.

The question remains whether reduced cerebral blood flow (CBF) leads to brain atrophy or vice versa. We studied the longitudinal relation between CBF and brain volume in a community-dwelling population. In the Rotterdam Study, 3011 participants (mean age 59.6 years (s.d. 8.0)) underwent repeat brain magnetic resonance imaging to quantify brain volume and CBF at two time points. Adjusted linear regression models were used to investigate the bidirectional relation between CBF and brain volume. We found that smaller brain volume at baseline was associated with a steeper decrease in CBF in the whole population (standardized change per s.d. increase of total brain volume (TBV)=0.296 (95% confidence interval (CI) 0.200; 0.393)). Only in persons aged ⩾65 years, a lower CBF at baseline was associated with steeper decline of TBV (standardized change per s.d. increase of CBF=0.003 (95% CI -0.004; 0.010) in the whole population and 0.020 (95% CI 0.004; 0.036) in those aged ⩾65 years of age). Our results indicate that brain atrophy causes CBF to decrease over time, rather than vice versa. Only in persons aged >65 years of age did we find lower CBF to also relate to brain atrophy.