Anthropometric risk factors for ovarian cancer in the NIH-AARP diet and health study

OBJECTIVE Identifying potentially modifiable risk factors for ovarian cancer is essential for prevention because this cancer is predominantly detected at a late stage. Here, we estimated the relations of general adiposity and measures reflecting body fat distribution to the risk of epithelial ovarian cancer. METHODS We ascertained 683 ovarian epithelial cancers (343 high-grade serous, 141 non-high grade serous) among 145,575 women, aged 50-72 years (median follow-up 12.6 years), from the National Institutes of Health-American Association of Retired Persons (NIH-AARP) Diet and Health Study. Using Cox models, we estimated confounder-adjusted hazard ratios (HRs) and 95% confidence intervals (CI) for associations of overall ovarian cancer, high-grade serous and non-high-grade serous carcinoma with body mass index, waist circumference, hip circumference, waist-hip ratio, waist-height ratio, body adiposity index, body shape index, and abdominal volume index. RESULTS Anthropometric measures were unrelated to overall ovarian cancer, high-grade serous cancer, and non-high-grade serous cancer. For example, the HR for overall ovarian cancer per standard deviation increment of body mass index at baseline was 0.98 (95% CI 0.88-1.10). Similar associations were observed with measurements of body fat distribution. CONCLUSION These results do not indicate that adult adiposity is associated with ovarian cancer risk in post-menopausal women

A Mendelian randomization study on the effect of 25‐hydroxyvitamin D levels on periodontitis

Abstract Background Twenty five‐hydroxy vitamin D (25OHD) levels have been proposed to protect against periodontitis based on in vitro and observational studies but evidence from long‐term randomized controlled trials (RCTs) is lacking. This study tested whether genetically proxied 25OHD is associated with periodontitis using Mendelian randomization (MR). Methods Genetic variants strongly associated with 25OHD in a genome‐wide association study (GWAS) of 417,580 participants of European ancestry were used as instrumental variables, and linked to GWAS summary data of 17,353 periodontitis cases and 28,210 controls. In addition to the main analysis using an inverse variance weighted (IVW) model, we applied additional robust methods to control for pleiotropy. We also undertook sensitivity analyses excluding single nucleotide polymorphisms (SNPs) used as instruments with potential pleiotropic effects and used a second 25OHD GWAS for replication. We identified 288 SNPs to be genome‐wide significant for 25OHD, explaining 7.0% of the variance of 25OHD levels and providing ≥90% power to detect an odds ratio (OR) of ≤ 0.97. Results MR analysis suggested that a 1 standard deviation increase in natural log‐transformed 25OHD was not associated with periodontitis risk (IVW OR = 1.04; 95% confidence interval (CI): 0.97–1.12; P‐value = 0.297). The robust models, replication, and sensitivity analyses were coherent with the primary analysis. Conclusions Collectively, our findings suggest that 25OHD levels are unlikely to have a substantial effect on the risk of periodontitis, but large long‐term RCTs are needed to derive definitive evidence on the causal role of 25OHD in periodontitis

Do proton pump inhibitors increase the risk of dementia? A systematic review, meta‐analysis and bias analysis

AimPrevious studies on the association between proton pump inhibitor (PPI) intake and the increased risk of dementia has shown discrepancies in their conclusions. We aimed to provide updated evidence based on extensive bias assessments and quantitative sensitivity analyses. MethodsWe searched the databases PubMed, EMBASE, SCOPUS, CENTRAL and for prospective studies that examined an association between PPI use and dementia, up to February 2022. Each study was assessed using the Cochrane risk of bias assessment tools for non-randomized studies of interventions (ROBINS-I) or randomized trials (RoB2). Pooled risk ratios (RRs) and 95% prediction intervals were computed using random-effects models. Sensitivity analyses were adjusted for small-study bias. ResultsWe included nine observational studies with 204 108 dementia cases in the primary analysis on the association between PPI use vs. non-use and dementia, and the RR was 1.16 (95% CI = 1.00;1.35). After adjusting for small-study bias by Copas selection model and Rucker's shrinkage procedure, the RR was 1.16 (1.02;1.32) and 1.15 (1.13;1.17), respectively. A subgroup analysis of PPI use vs. non-use regarding Alzheimer's disease risk yielded an RR of 1.15 (0.89;1.50). The secondary analysis on the risk of dementia by use of PPI vs. histamine-2 receptor antagonist showed an RR of 1.03 (0.66;1.62). ConclusionThis meta-analysis provided no clear evidence for an association between PPI intake and the risk of dementia. Due to discrepancies in sensitivity analyses, however, some risk of dementia by PPI use cannot be ruled out. Since an unequivocal conclusion is still pending, further research is warranted

Emulating a target trial of proton pump inhibitors and dementia risk using claims data

Background and purpose Understanding the adverse effects of proton pump inhibitors (PPIs) is important due to their widespread use, but the available evidence for an increased dementia risk amongst patients taking PPIs is inconclusive. The present study aimed to estimate the causal effect of PPIs on the risk of dementia by target trial emulation and time-varying exposure modeling. Methods Using claims data of 2,698,176 insured people of a large German statutory health insurer, a target trial was conceptualized in which individuals aged 40 years and older were classified as PPI initiators or non-initiators between 2008 and 2018, and were followed until diagnosis of dementia, death, loss to follow-up or end of study. Incidence of dementia (International Classification of Diseases 10 codes F00, F01, F03, F05.1, G30, G31.0, G31.1, G31.9 and F02.8+G31.82) was defined applying a 1-year lag window. Weighted Cox models were used to estimate the effect of PPI initiation versus non-initiation on dementia risk and weighted pooled logistic regression was used to estimate the effect of time-varying use versus non-use. Results In all, 29,746 PPI initiators (4.4%) and 26,830 non-initiators (1.3%) were diagnosed with dementia. Comparing PPI initiation with no initiation, the hazard ratio for dementia was 1.54 (95% confidence interval 1.51-1.58). The hazard ratio for time-dependent PPI use versus non-use was 1.56 (95% confidence interval 1.50-1.63). Differentiated subtypes, including unspecified dementia, Alzheimer's disease and vascular dementia, showed increased risk by PPI initiation and time-varying PPI use. Conclusions This study suggests that PPI initiation and time-varying PPI use may increase overall dementia risk

No bidirectional relationship between depression and periodontitis: A genetic correlation and Mendelian randomization study

BackgroundObservational and in-vivo research suggested a bidirectional relationship between depression and periodontitis. We estimated the genetic correlation and examined directionality of causation.MethodsThe study used summary statistics from published genome wide association studies, with sample sizes ranging from 45,563 to 797,563 individuals of European ancestry. We performed linkage disequilibrium score regression (LDSC) to estimate global correlation and used Heritability Estimation from Summary Statistics (ρ-HESS) to further examine local genetic correlation. Latent Heritable Confounder Mendelian randomization (LHC-MR), Causal Analysis using Summary Effect estimates (CAUSE), and conventional MR approaches assessed bidirectional causation.ResultsLDSC observed only weak genetic correlation (rg = 0.06, P-Value = 0.619) between depression and periodontitis. Analysis of local genetic correlation using ρ-HESS did not reveal loci of significant local genetic covariance. LHC-MR, CAUSE and conventional MR models provided no support for bidirectional causation between depression and periodontitis, with odds ratios ranging from 1.00 to 1.06 in either direction.ConclusionsResults do not support shared heritability or a causal connection between depression and periodontitis

Association between usual dietary intake of food groups and DNA methylation and effect modification by metabotype in the KORA FF4 cohort

Associations between diet and DNA methylation may vary among subjects with different metabolic states, which can be captured by clustering populations in metabolically homogenous subgroups, called metabotypes. Our aim was to examine the relationship between habitual consumption of various food groups and DNA methylation as well as to test for effect modification by metabotype. A cross-sectional analysis of participants (median age 58 years) of the population-based prospective KORA FF4 study, habitual dietary intake was modeled based on repeated 24-h diet recalls and a food frequency questionnaire. DNA methylation was measured using the Infinium MethylationEPIC BeadChip providing data on >850,000 sites in this epigenome-wide association study (EWAS). Three metabotype clusters were identified using four standard clinical parameters and BMI. Regression models were used to associate diet and DNA methylation, and to test for effect modification. Few significant signals were identified in the basic analysis while many significant signals were observed in models including food group-metabotype interaction terms. Most findings refer to interactions of food intake with metabotype 3, which is the metabotype with the most unfavorable metabolic profile. This research highlights the importance of the metabolic characteristics of subjects when identifying associations between diet and white blood cell DNA methylation in EWAS

Relationship between periodontitis and psoriasis: A two‐sample Mendelian randomization study

Aim Observational research suggests that periodontitis affects psoriasis. However, observational studies are prone to reverse causation and confounding, which hampers drawing causal conclusions and the effect direction. We applied the Mendelian randomization (MR) method to comprehensively assess the potential bi-directional association between periodontitis and psoriasis. Materials and Methods We used genetic instruments from the largest available genome-wide association study of European descent for periodontitis (17,353 cases, 28,210 controls) to investigate the relationship with psoriasis (13,229 cases, 21,543 controls), and vice versa. Causal Analysis Using Summary Effect (CAUSE) estimates and inverse variance-weighted (IVW) MR analyses were used for the primary analysis. Robust MR approaches were used for sensitivity analyses. Results Both univariable methods, CAUSE and IVW MR analyses, did not reveal any impact of periodontitis on psoriasis (CAUSE odds ratio [OR] = 1.00, p = 1.00; IVW OR = 1.02, p = .6247), or vice versa (CAUSE OR = 1.01, p = .5135; IVW OR = 1.00, p = .7070). The null association was corroborated by pleiotropy-robust methods with ORs close to 1 and p-values >.59. Overall, MR analyses did not suggest any effect of periodontitis on psoriasis. Similarly, there was no evidence to support an effect of psoriasis on periodontitis. Conclusions Within the limitations of this MR study, the outcomes supported neither periodontitis affecting psoriasis nor psoriasis affecting periodontitis

Downregulation of interleukin 6 signaling might reduce the risk of periodontitis: a drug target Mendelian randomization study

AimInterleukin 6 (IL-6) is considered to play a role in the dysbiotic host response in the development of periodontitis. While the inhibition of the IL-6 receptor using monoclonal antibodies is a well-established therapy for some diseases, so far, its potential benefit in patients with periodontitis has not been examined. We tested the association of genetically proxied downregulation of IL-6 signaling with periodontitis to explore whether downregulation of IL-6 signaling could represent a viable treatment target for periodontitis,Materials and methodsAs proxies for IL-6 signaling downregulation, we selected 52 genetic variants in close vicinity of the gene encoding IL-6 receptor that were associated with lower circulating C-reactive protein (CRP) levels in a genome-wide association study (GWAS) of 575 531 participants of European ancestry from the UK Biobank and the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) consortium. Associations with periodontitis were tested with inverse-variance weighted Mendelian randomization in a study of 17 353 cases and 28 210 controls of European descent in the Gene-Lifestyle Interactions in Dental Endpoints (GLIDE) consortium. In addition, the effect of CRP reduction independent of the IL-6 pathway was assessed.ResultsGenetically proxied downregulation of IL-6 signaling was associated with lower odds of periodontitis (odds ratio (OR) = 0.81 per 1-unit decrement in log-CRP levels; 95% confidence interval (CI): [0.66;0.99]; P = 0.0497). Genetically proxied reduction of CRP independent of the IL-6 pathway had a similar effect (OR = 0.81; 95% CI: [0.68; 0.98]; P = 0.0296).ConclusionIn conclusion, genetically proxied downregulation of IL-6 signaling was associated with lower odds of periodontitis and CRP might be a causal target for the effect of IL-6 on the risk of periodontitis