Personality and the use of cancer screenings - Results of the German National Cohort

Objective

To determine the association between personality characteristics and use of different cancer screenings.

Methods

We used data from the German National Cohort (NAKO; mean age was 53.0 years (SD: 9.2 years)) - a population-based cohort study. A total of 132,298 individuals were included in the analyses. As outcome measures, we used (self-reported): stool examination for blood (haemoccult test, early detection of bowel cancer), colonoscopy (screening for colorectal cancer), skin examination for moles (early detection of skin cancer), breast palpation by a doctor (early detection of breast cancer), x-ray examination of the breast ("mammography", early detection of breast cancer), cervical smear test, finger examination of the rectum (early detection of prostate cancer), and blood test for prostate cancer (determination of Prostate-Specific Antigen level). The established Big Five Inventory-SOEP was used to quantify personality factors. It was adjusted for several covariates based on the Andersen model. Unadjusted and adjusted multiple logistic regressions were computed.

Results

A higher probability of having a skin examination for moles, for example, was associated with a higher conscientiousness (OR: 1.07, p < 0.001), higher extraversion (OR: 1.03, p < 0.001), higher agreeableness (OR: 1.02, p < 0.001), lower openness to experience (OR: 0.98, p < 0.001) and higher neuroticism (OR: 1.07, p < 0.001) among the total sample. Depending on the outcome used, the associations slightly varied.

Conclusions

Particularly higher levels of extraversion, neuroticism and conscientiousness are associated with the use of different cancer screenings. Such knowledge may help to better understand non-participation in cancer screening examinations from a psychological perspective.

Tissue-specific genetic variation suggests distinct molecular pathways between body shape phenotypes and colorectal cancer

It remains unknown whether adiposity subtypes are differentially associated with colorectal cancer (CRC). To move beyond single-trait anthropometric indicators, we derived four multi-trait body shape phenotypes reflecting adiposity subtypes from principal components analysis on body mass index, height, weight, waist-to-hip ratio, and waist and hip circumference. A generally obese (PC1) and a tall, centrally obese (PC3) body shape were both positively associated with CRC risk in observational analyses in 329,828 UK Biobank participants (3728 cases). In genome-wide association studies in 460,198 UK Biobank participants, we identified 3414 genetic variants across four body shapes and Mendelian randomization analyses confirmed positive associations of PC1 and PC3 with CRC risk (52,775 cases/45,940 controls from GECCO/CORECT/CCFR). Brain tissue-specific genetic instruments, mapped to PC1 through enrichment analysis, were responsible for the relationship between PC1 and CRC, while the relationship between PC3 and CRC was predominantly driven by adipose tissue-specific genetic instruments. This study suggests distinct putative causal pathways between adiposity subtypes and CRC.

Multi-Trait Body Shape Phenotypes and Breast Cancer Risk in Postmenopausal Women: A Causal Mediation Analysis in the UK Biobank Cohort

Body shape phenotypes combining multiple anthropometric traits have been linked to postmenopausal breast cancer (BC). However, underlying biological pathways remain poorly understood. This study investigated to what extent the associations of body shapes with postmenopausal BC risk is mediated by biochemical markers. The study included 176,686 postmenopausal women from UK Biobank. Four body shape phenotypes were derived from principal component (PC) analysis of height, weight, body mass index, waist and hip circumferences, and waist-to-hip ratio (WHR). The four-way decomposition of the total effect was used to estimate mediation and interaction effects simultaneously as well as the mediated proportions. After 10.9 years median follow-up, 6,396 incident postmenopausal BC were diagnosed. There was strong evidence of positive associations between PC1 (general obesity) and PC2 (tall, low WHR), and BC risk. The association of PC1 with BC risk was positively mediated by testosterone and negatively by insulin-like growth factor-1 (IGF-1), with the overall proportion mediated (sum of the mediated interaction and pure indirect effect (PIE)) accounting for 11.4% (95% confidence intervals: 5.1 to 17.8%) and -12.2% (-20.5% to -4.0%) of the total effect, respectively. Small proportions of the association between PC2 and BC were mediated by IGF-1 (PIE: 2.8% (0.6 to 4.9%)), and sex hormone-binding globulin (SHBG) (PIE: -6.1% (-10.9% to -1.3%)). Our findings are consistent with differential pathways linking different body shapes with BC risk, with a suggestive mediation through testosterone and IGF-1 in the relationship of a generally obese body shape and BC risk, while IGF-1 and SHBG may mediate a tall/lean body shape-BC risk association.

Large-scale assessment of physical activity in a population using high-resolution hip-worn accelerometry: the German National Cohort (NAKO)

Large population-based cohort studies utilizing device-based measures of physical activity are crucial to close important research gaps regarding the potential protective effects of physical activity on chronic diseases. The present study details the quality control processes and the derivation of physical activity metrics from 100 Hz accelerometer data collected in the German National Cohort (NAKO). During the 2014 to 2019 baseline assessment, a subsample of NAKO participants wore a triaxial ActiGraph accelerometer on their right hip for seven consecutive days. Auto-calibration, signal feature calculations including Euclidean Norm Minus One (ENMO) and Mean Amplitude Deviation (MAD), identification of non-wear time, and imputation, were conducted using the R package GGIR version 2.10-3. A total of 73,334 participants contributed data for accelerometry analysis, of whom 63,236 provided valid data. The average ENMO was 11.7 ± 3.7 mg (milli gravitational acceleration) and the average MAD was 19.9 ± 6.1 mg. Notably, acceleration summary metrics were higher in men than women and diminished with increasing age. Work generated in the present study will facilitate harmonized analysis, reproducibility, and utilization of NAKO accelerometry data. The NAKO accelerometry dataset represents a valuable asset for physical activity research and will be accessible through a specified application process.

Complement C3 as a potential drug target in periodontitis: Evidence from the cis-Mendelian randomization approach

AIM

Evidence from a Phase IIa trial showed that a complement C3-targeted drug reduced gingival inflammation in patients with gingivitis. Using drug-target Mendelian randomization (MR), we investigated whether genetically proxied C3 inhibition alters the risk of periodontitis.

MATERIALS AND METHODS

We used multiple 'cis' instruments from the vicinity of the encoding loci of C3. Instrument selection was restricted to the drug target encoding loci (chromosome 19; 6,677,715-6,730,573 (GRCh37/hg19)). We selected three uncorrelated single-nucleotide polymorphisms (rs141552034, rs145406915, rs11569479) that were associated with serum C3 levels (p value <1 × 10-4 ) from a genome-wide association study (GWAS) of 5368 European descent individuals. We extracted association statistics from a GWAS of 17,353 clinical periodontitis cases and 28,210 European controls. Wald ratios were combined using inverse-variance weighted meta-analysis to estimate the odds ratio (OR) of the genetically proxied inhibition of C3 in relation to periodontitis.

RESULTS

MR analysis revealed that the inhibition of C3 reduces the odds of periodontitis (OR 0.91 per 1 standard deviation reduction in C3; 95% confidence interval 0.87-0.96, p value = .0003).

CONCLUSIONS

Findings from our MR analysis suggest a potential protective effect of C3 blockade against periodontitis.

Moderate Intensity Exercise Reduces Side Effects of Cancer Therapy and Maintains Cardiorespiratory Fitness in Male Breast Cancer Patients: Findings from the BRECA Male Crossover Study

Introduction

There is growing evidence that aerobic exercise mitigates cancer therapy-related side effects and improves cardiorespiratory fitness (CRF). However, to the best of our knowledge, no exercise study has been conducted in male breast cancer (MBC) patients. The aim of this study was to investigate the feasibility and efficacy of different exercise intensities on CRF and self-reported questionnaire items in MBC patients.

Methods

Twenty-two MBC patients (60 ± 9 years) participated in this randomized crossover study. After completion of medical treatment, MBC patients were randomly assigned to either moderate (40-50% of heart rate [HR] max. and self-perceived exertion: 11) or vigorous (70-80% of HR max. and self-perceived exertion: 15) exercise intensity during the first 3 months of the study. After a 1-month washout period, participants switched group assignments. Primary endpoints were CRF and questionnaire items.

Results

We observed a dropout rate of 36% over 7 months, with the number of participants decreasing from 22 to 14. The results showed significant improvements in "Physical Function" (p = 0.037) and "Social Function" (p = 0.016) after moderate training. A non-significant improvement was also observed in "Breast Symptoms" (p = 0.095), but there was no change in "Fatigue" (p = 0.306). There were no differences observed in cardiovascular fitness (V̇O2 peak) between the treatment groups.

Conclusion

This study emphasizes the effectiveness of exercise intervention for an exceedingly rare cancer, highlighting the vital role of moderate intensity aerobic exercise in mitigating treatment side effects. Despite minimal peak V̇O2 differences, both exercise protocols adequately sustain CRF. Future studies are imperative to design optimized, sex-specific rehabilitation strategies tailored to the unique requirements of MBC patients, advancing our understanding of this under explored realm.

Cannabis use and the risk of primary open-angle glaucoma: a Mendelian randomization study

Several observational studies have investigated the association between cannabis use and intraocular pressure, but its association with primary open-angle glaucoma (POAG) remains unclear. In this study, we leveraged human genetic data to assess through Mendelian randomization (MR) whether cannabis use affects POAG. We used five single-nucleotide polymorphisms (SNPs) associated with lifetime cannabis use (P-value < 5 × 10-8) from a genome-wide association study (GWAS) (N = 184,765) by the International Cannabis Consortium, 23andMe, and UK Biobank and eleven SNPs associated with cannabis use disorder (P-value < 5 × 10-7) from a GWAS meta-analysis of (17,068 cases and 357,219 controls of European descent) from Psychiatric Genomics Consortium Substance Use Disorders working group, Lundbeck Foundation Initiative for Integrative Psychiatric Research, and deCode. We associated the selected five SNPs from the GWAS of lifetime cannabis use and the eleven SNPs from the GWAS of cannabis use disorder, with the largest to date GWAS meta-analysis of POAG (16,677 cases and 199,580 controls). MR analysis suggested no evidence for a causal association of lifetime cannabis use and cannabis use disorder with POAG (odds ratio (OR) of outcome per doubling of the odds of exposure (95% confidence interval): 1.04 (0.88; 1.23) for lifetime cannabis use and 0.97 (0.92; 1.03) for cannabis use disorder). Sensitivity analyses to address pleiotropy and weak instrument bias yielded similar estimates to the primary analysis. In conclusion, our results do not support a causal association between cannabis use and POAG.

Association between circadian physical activity patterns and mortality in the UK Biobank

BACKGROUND

The benefit of physical activity (PA) for increasing longevity is well-established, however, the impact of diurnal timing of PA on mortality remains poorly understood. We aimed to derive circadian PA patterns and investigate their associations with all-cause mortality.

METHODS

We used 24 h PA time series from 96,351 UK Biobank participants aged between 42 and 79 years at accelerometry in 2013-2015. Functional principal component analysis (fPCA) was applied to obtain circadian PA patterns. Using multivariable Cox proportional hazard models, we related the loading scores of these fPCs to estimate risk of mortality.

RESULTS

During 6.9 years of follow-up, 2,850 deaths occurred. Four distinct fPCs accounted for 96% of the variation of the accelerometry data. Using a loading score of zero (i.e., average overall PA during the day) as the reference, a fPC1 score of + 2 (high overall PA) was inversely associated with mortality (Hazard ratio, HR = 0.91; 95% CI: 0.84-0.99), whereas a score of -2 (low overall PA) was associated with higher mortality (1.69; 95% CI: 1.57-1.81; p for non-linearity < 0.001). Significant inverse linear associations with mortality were observed for engaging in midday PA instead of early and late PA (fPC3) (HR for a 1-unit increase 0.88; 95% CI: 0.83-0.93). In contrast, midday and nocturnal PA instead of early and evening PA (fPC4) were positively associated with mortality (HR for a 1-unit increase 1.16; 95% CI: 1.08-1.25).

CONCLUSION

Our results suggest that it is less important during which daytime hours one is active but rather, to engage in some level of elevated PA for longevity.

Physical activity and the risk of periodontitis: an instrumental variable study

OBJECTIVES

Observational studies suggested an inverse association between physical activity and periodontitis. However, observational studies might be subject to unobserved confounding and reverse causation bias. We conducted an instrumental variable study to strengthen the evidence on the relationship between physical activity and periodontitis.

MATERIALS AND METHODS

We used genetic variants associated with self-reported and accelerometer-assessed physical activity in 377,234 and 91,084 UK Biobank participants, respectively, as instruments. For these instruments, genetic associations with periodontitis were obtained from 17,353 cases and 28,210 controls in the GeneLifestyle Interactions in Dental Endpoints consortium.

RESULTS

We found no evidence for effects of self-reported moderate-to-vigorous physical activity, self-reported vigorous physical activity, accelerometry "average accelerations," and "fraction of accelerations > 425 milli-gravities" on periodontitis. For example, the odds ratio for self-reported moderate-to-vigorous physical activity was 1.07 (95% credible interval: 0.87; 1.34) in Causal Analysis using Summary Effect Estimates. We conducted sensitivity analyses to rule out weak instrument bias and correlated horizontal pleiotropy.

CONCLUSIONS

The study does not support an effect of physical activity on the risk of periodontitis.

CLINICAL RELEVANCE

This study provides little evidence that recommending physical activity would help prevent periodontitis.

Association of epidemiological and clinical features with PCR cycle threshold values of SARS-CoV-2 infection: a cross-sectional study

The cycle threshold (Ct) in quantitative real-time reverse-transcriptase polymerase chain reaction (qRT-PCR) is inversely correlated to the amount of viral nucleic acid or viral load and can be regarded as an indicator of infectivity. We examined the association of socio-demographic and clinical characteristics of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) polymerase chain reaction (PCR) positive cases with PCR cycle threshold (Ct) values at the time of diagnosis. SARS-CoV-2 cases reported between 12 October 2020 and 24 January 2021 in Regensburg were analyzed employing bivariate and multivariable methods. We included 3,029 SARS-CoV-2 cases (31% asymptomatic at diagnosis) and analyzed the association of case characteristics with Ct values in 2,606 cases. Among symptomatic patients, cough (38.0%), rhinitis (32.4%), headache (32.0), and fever/chills (29.9%) were the most frequent complaints. Ct values ≤20 were more frequent in symptomatic cases (20.9% vs. 11.3%), whereas Ct values >30 were more common in asymptomatic cases (32.6% vs. 18.0%). Ct values >20 and ≤30 were most common in symptomatic and asymptomatic cases (48.0% vs 40.7%). We observed lower median Ct values of E and N gene in symptomatic cases. In a random forest model, the total number of symptoms, respiratory symptoms, and age were most strongly associated with low Ct values. In conclusion, certain symptoms and age were associated with lower Ct values. Ct values can be used as a pragmatic approach in estimating infectivity at the first notification of a case and, thus, in guiding containment measures.

Relationship between genetically proxied vitamin D and psoriasis risk: a Mendelian randomization study

BACKGROUND

Observational research suggests that vitamin D levels affect psoriasis. However, observational studies are prone to potential confounding or reverse causation, which complicates interpreting the data and drawing causal conclusions.

AIM

To apply Mendelian randomization (MR) methods to comprehensively assess a potential association between vitamin D and psoriasis.

METHODS

Genetic variants strongly associated with 25-hydroxyvitamin D (25OHD) in genome-wide association study (GWAS) data from 417 580 and 79 366 individuals from two independent studies served as instrumental variables (used as the discovery and replication datasets, respectively). As the outcome variable, we used GWAS data of psoriasis (13 229 people in the case group, 21 543 in the control group). We used (i) biologically validated genetic instruments, and (ii) polygenic genetic instruments to assess the relationship between genetically proxied vitamin D and psoriasis. We carried out inverse-variance weighted (IVW) MR analyses for the primary analysis. In sensitivity analyses, we used robust MR approaches.

RESULTS

MR analyses of both the discovery and replication datasets did not show an effect of 25OHD on psoriasis. Neither the IVW MR analysis of the biologically validated instruments [discovery dataset: odds ratio (OR) 0.99; 95% confidence interval (CI) 0.88-1.12, P = 0.873; replication dataset: OR 0.98, 95% CI 0.66-1.46, P = 0.930] nor that of the polygenic genetic instruments (discovery dataset: OR 1.00, 95% CI 0.81-1.22, P = 0.973; replication dataset: OR 0.94, 95% CI 0.64-1.38, P = 0.737) revealed an impact of 25OHD on psoriasis.

CONCLUSION

The present MR study did not support the hypothesis that vitamin D levels, measured by 25OHD, affect psoriasis. This study was conducted on Europeans, so the conclusions may not be applicable to all ethnicities.

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

Aim

Interleukin 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 methods

As 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.

Results

Genetically 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).

Conclusion

In 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.

Effect of 25-hydroxyvitamin D levels on the internalising dimension as a transdiagnostic risk factor: Mendelian randomisation study

BACKGROUND

Observational studies indicate a relationship between vitamin D (25-hydroxyvitamin D; 25OHD) deficiency and the development of internalising disorders, especially depression. However, causal inference approaches (e.g. Mendelian randomisation) did not confirm this relationship. Findings from biobehavioural research suggests that new insights are revealed when focusing on psychopathological dimensions rather than on clinical diagnoses. This study provides further evidence on the relationship between 25OHD and the internalising dimension.

AIMS

This investigation aimed at examining the causality between 25OHD and internalising disorders including a common internalising factor.

METHOD

We performed a two-sample Mendelian randomisation using genome-wide association study (GWAS) summary data for 25OHD (417 580 participants), major depressive disorder (45 591 cases; 97 674 controls), anxiety (5580 cases; 11 730 controls), post-traumatic stress disorder (12 080 cases; 33 446 controls), panic disorder (2248 cases; 7992 controls), obsessive-compulsive disorder (2688 cases; 7037 controls) and anorexia nervosa (16 992 cases; 55 525 controls). GWAS results of the internalising phenotypes were combined to a common factor representing the internalising dimension. We performed several complementary analyses to reduce the risk of pleiotropy and used a second 25OHD GWAS for replication.

RESULTS

We found no causal relationship between 25OHD and any of the internalising phenotypes studied, nor with the common internalising factor. Several pleiotropy-robust methods corroborated the null association.

CONCLUSIONS

Following current transdiagnostic approaches to investigate mental disorders, our results focused on the shared genetic basis between different internalising phenotypes and provide no evidence for an effect of 25OHD on the internalising dimension.

Suicide Mortality Risk among Patients with Lung Cancer-A Systematic Review and Meta-Analysis

The risk for suicide in patients with cancer is higher compared to the general population. However, little is known about patients with lung cancer specifically. We therefore implemented a systematic review and random-effects meta-analysis of retrospective cohort studies on suicide in patients with lung cancer. We searched a high number of common databases up to 02/2021. For the systematic review, a total of 23 studies was included. To exclude bias due to patient sample overlap, the meta-analysis was performed on 12 studies. The pooled standardized mortality ratio (SMR) for suicide was 2.95 (95% Confidence Interval (CI) = 2.42-3.60) for patients with lung cancer as compared to the general population. Subgroups with a pronouncedly higher risk for suicide compared to the general population were found for patients living in the USA (SMR = 4.17, 95% CI = 3.88-4.48), with tumors of late stage (SMR = 4.68, 95% CI = 1.28-17.14), and within one year after diagnosis (SMR = 5.00, 95% CI = 4.11-6.08). An increased risk for suicide was found in patients with lung cancer, with subgroups at particular risk. Patients at increased risk should be monitored more closely for suicidality and should receive specialized psycho-oncological and psychiatric care. Further studies should clarify the role of smoking and depressive symptoms on suicidality among lung cancer patients.

Inhibition of tumor necrosis factor receptor 1 and the risk of periodontitis

Aim

To investigate the effect of genetically proxied inhibition of tumor necrosis factor receptor 1 (TNFR1) on the risk of periodontitis.

Materials and methods

Genetic instruments were selected from the vicinity of TNFR superfamily member 1A (TNFRSF1A) gene (chromosome 12; base pairs 6,437,923-6,451,280 as per GRCh37 assembly) based on their association with C-reactive protein (N= 575,531). Summary statistics of these variants were obtained from a genome-wide association study (GWAS) of 17,353 periodontitis cases and 28,210 controls to estimate the effect of TNFR1 inhibition on periodontitis using a fixed-effects inverse method.

Results

Considering rs1800693 as an instrument, we found no effect of TNFR1 inhibition on periodontitis risk (Odds ratio (OR) scaled per standard deviation increment in CRP: 1.57, 95% confidence interval (CI): 0.38;6.46). Similar results were derived from a secondary analysis that used three variants (rs767455, rs4149570, and rs4149577) to index TNFR1 inhibition.

Conclusions

We found no evidence of a potential efficacy of TNFR1 inhibition on periodontitis risk.

Body shape phenotypes of multiple anthropometric traits and cancer risk: a multi-national cohort study

BACKGROUND

Classical anthropometric traits may fail to fully represent the relationship of weight, adiposity, and height with cancer risk. We investigated the associations of body shape phenotypes with the risk of overall and site-specific cancers.

METHODS

We derived four distinct body shape phenotypes from principal component (PC) analysis on height, weight, body mass index (BMI), waist (WC) and hip circumferences (HC), and waist-to-hip ratio (WHR). The study included 340,152 men and women from 9 European countries, aged mostly 35-65 years at recruitment (1990-2000) in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Cox proportional hazards regression was used to estimate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

After a median follow-up of 15.3 years, 47,110 incident cancer cases were recorded. PC1 (overall adiposity) was positively associated with the risk of overall cancer, with a HR per 1 standard deviation (SD) increment equal to 1.07 (95% confidence interval 1.05 to 1.08). Positive associations were observed with 10 cancer types, with HRs (per 1 SD) ranging from 1.36 (1.30-1.42) for endometrial cancer to 1.08 (1.03-1.13) for rectal cancer. PC2 (tall stature with low WHR) was positively associated with the risk of overall cancer (1.03; 1.02-1.04) and five cancer types which were not associated with PC1. PC3 (tall stature with high WHR) was positively associated with the risk of overall cancer (1.04; 1.03-1.05) and 12 cancer types. PC4 (high BMI and weight with low WC and HC) was not associated with overall risk of cancer (1.00; 0.99-1.01).

CONCLUSIONS

In this multi-national study, distinct body shape phenotypes were positively associated with the incidence of 17 different cancers and overall cancer.

Targeted therapies in patients with newly diagnosed glioblastoma-A systematic meta-analysis of randomized clinical trials

Glioblastoma (GB) is the most common malignant primary brain tumor in adults. The standard of care for newly diagnosed GB involves surgical resection followed by radiochemotherapy with temozolomide, with or without tumor-treating fields. In recent years, various efforts have been made to identify suitable molecularly targeted treatment options for malignant brain tumors. This meta-analysis provides an overview of recently published randomized controlled trials (RCTs) with and without molecular stratification, analyzing targeted agents in patients with newly diagnosed GB. The Cochrane Library, MEDLINE (Ovid), ClinicalTrials.gov, WHO's International Clinical Trials Registry Platform, and Google Scholar were searched for RCTs on targeted therapies in patients with newly diagnosed glioblastoma. Hazard ratios (HRs) for overall survival (OS) and progression-free survival (PFS) were extracted and pooled in a random-effects meta-analysis. Twelve RCTs (n = 3941 patients) involving protein kinase inhibitors, proteasome and histone deacetylase inhibitors, anti-angiogenic approaches and poly (ADP-ribose) polymerase (PARP) inhibitors were included in the meta-analysis. None of the targeted agents achieved a significant benefit with regard to OS (HR = 0.98 [95% confidence interval (CI) 0.86-1.11, P = .7731]). By comparison, targeted therapy showed a benefit for PFS (HR = 0.83 [95% CI 0.74-0.94, P = .0037]), especially for patients with an unmethylated O6-methylguanine-DNA-methyltransferase (MGMT) promoter (0.75 [95% CI 0.56-0.99, P = .0440]). Prolongation of PFS was largely driven by VEGF inhibition with bevacizumab (HR = 0.70 [95% CI 0.61-0.80, P = .0000]). VEGF inhibition with bevacizumab prolonged PFS in patients with newly diagnosed glioblastoma compared to standard care. However, no improvement in OS was observed with any of the targeted agents.

Effect of interleukin-17 on periodontitis development: An instrumental variable analysis

BACKGROUND

Circulating levels of interleukin-17 (IL-17) are associated with the presence and severity of periodontitis. However, whether IL-17 is causal for disease development is unknown. We investigated the effect of genetically proxied IL-17 on periodontitis using instrumental variable analysis.

METHODS

We identified 12 genetic variants from genome-wide association study (GWAS) of 7760 European descent individuals, used these variants as instrumental variables for IL-17, and linked them to a GWAS of 17,353 clinical periodontitis cases and 28,210 European controls. Generalized weighted least squares analysis accounted for linkage disequilibrium of variants.

RESULTS

We found an inverse association of genetically proxied IL-17 and periodontitis (odds ratio, 0.84; 95% confidence interval: 0.75-0.94; p = 0.003), which was corroborated after sensitivity analysis for horizontal pleiotropy.

CONCLUSION

The findings suggest that IL-17 protects against initial periodontitis.

Genotype-driven NPC1L1 and PCSK9 inhibition and reduced risk of periodontitis

AIM

Epidemiological and pre-clinical studies suggest a chemoprotective role of lipid-lowering agents in periodontitis. We tested the association of genetically proxied inhibition of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR), Niemann-Pick C1-Like 1 (NPC1L1) and proprotein convertase subtilisin/kexin type 9 (PCSK9) with periodontitis.

MATERIALS AND METHODS

Genetic variants in HMGCR, NCP1L1 and PCSK9 associated with low-density lipoprotein (LDL) cholesterol in a genome-wide association study (GWAS) meta-analysis (N = 188,578) were used to proxy therapeutic inhibition of HMGCR, NPC1L1 and PCSK9. For these genetic variants, associations with periodontitis were obtained from GWAS of 17,353 cases and 28,210 controls in the GeneLifestyle Interactions in Dental Endpoints consortium. Generalized weighted least squares analysis accounted for linkage disequilibrium of genotypes to derive pooled estimates.

RESULTS

While genetically proxied HMGCR inhibition equivalent to 1 mmol/L reduction in LDL was not associated with odds of periodontitis (odds ratio [OR] = 0.92 [95% confidence interval [CI]: 0.73; 1.16]; p = .4905; false discovery rate [FDR] = 0.4905), genetically proxied NPC1L1 (OR = 0.53 [95% CI: 0.35; 0.81]; p = .0038; FDR = 0.0077) and PCSK9 (OR = 0.84 [95% CI: 0.74; 0.95]; p = .0051; FDR = 0.0077) inhibition lowered the odds of periodontitis.

CONCLUSIONS

Genetically proxied inhibition of NCP1L1 and PCSK9 was associated with lower odds of periodontitis.

Association between total body bone mineral density and periodontitis: A Mendelian randomization study

BACKGROUND

The purpose of the study was to examine the association between total body bone mineral density (BMD) and periodontitis using Mendelian randomization (MR) analysis.

METHODS AND MATERIALS

We used 81 single nucleotide polymorphisms (SNPs) associated with BMD at a p-value of < 5 × 10^-8 from a genome-wide association study (GWAS) of 66,628 individuals of European descent. The GWAS for periodontitis was derived from a meta-analysis of seven cohort studies that included 17,353 cases and 28,210 controls of European ancestry.

RESULTS

MR showed no association between BMD and periodontitis (odds ratio per standard deviation increment in genetically predicted BMD = 1.00; 95% confidence interval: 0.92-1.08). Leave-one-out analyses and pleiotropy-robust methods did not indicate any bias.

CONCLUSIONS

The MR study provided no evidence that BMD might be causally linked to periodontitis. Hence it may be concluded as the key finding that BMD depletion does not increase the risk of periodontitis.

The Effectiveness of Interventions to Reduce Sedentary Time in Different Target Groups and Settings in Germany: Systematic Review, Meta-Analysis and Recommendations on Interventions

BACKGROUND

Sedentary behavior is an important risk factor for several chronic diseases and is associated with an increased risk of mortality. We assessed the effectiveness of interventions to reduce sedentary time in Germany and provide recommendations on interventions to reduce sedentary time in children and adults.

METHODS

We comprehensively searched PubMed, Web of Science and the German Clinical Trials Register up to April 2022 for intervention studies targeting sedentary behavior in Germany. We performed a systematic review and qualitative synthesis of the interventions and a meta-analysis in children.

RESULTS

We included 15 studies comprising data from 4588 participants. The results of included primary studies in adults and children showed inconsistent evidence regarding change in sedentary time, with a majority of studies reporting non-significant intervention effects. The meta-analysis in children showed an increase in sedentary time for children in the control and intervention groups.

CONCLUSION

We found inconsistent evidence regarding the effectiveness of interventions to reduce time spent sedentary and our meta-analysis showed an increase in sedentary time in children. For children, we recommend physical and social environment interventions with an active involvement of families. For adults, we recommend physical environment interventions, such as height-adjustable desks at work.

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

Background

Observational and in-vivo research suggested a bidirectional relationship between depression and periodontitis. We estimated the genetic correlation and examined directionality of causation.

Methods

The 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.

Results

LDSC observed only weak genetic correlation (r_g = 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.

Conclusions

Results do not support shared heritability or a causal connection between depression and periodontitis.

Cannabis use and the risk of periodontitis: A two-sample Mendelian randomization study

AIM

This study aimed to leverage human genetic data to investigate whether cannabis use causally affects periodontitis.

MATERIALS AND METHODS

Data were obtained from summary statistics of genome-wide association studies of lifetime cannabis use (N = 184,765), cannabis use disorder (17,068 cases; 357,219 controls), and periodontitis (17,353 cases; 28,210 controls). We performed two-sample Mendelian randomization (MR) analysis using 6 genetic variants as instrumental variables for lifetime cannabis use and 11 variants as instruments for cannabis use disorder to estimate associations with periodontitis.

RESULTS

There was no evidence for an association between genetic liability for lifetime cannabis use or cannabis use disorder with periodontitis. The estimates from the primary analyses were supported in multivariable MR analysis, which considered potential pleiotropic pathways and in weak instrument analyses.

CONCLUSIONS

This study provides little evidence to support a detrimental effect of genetic liability for cannabis use on periodontal health.

Calcium intake in vegan and vegetarian diets: A systematic review and Meta-analysis

In recent years, plant-based diets have experienced increasing popularity. However, plant-based diets may not always ensure an adequate supply of micronutrients, in particular calcium. We performed a systematic review and meta-analysis of calcium intake in vegan and vegetarian diets as compared to omnivorous diets. We searched PubMed and Web of Science and identified 2,009 potentially relevant articles. Mean calcium intake values were pooled and standardized mean differences (SMD) and 95% confidence intervals (CI) were computed.We analyzed 74 studies, including 7,356 vegan, 51,940 vegetarian, and 107,581 omnivorous participants. Of these, dietary calcium intake was examined in 23 studies of vegans, 60 studies of vegetarians and 74 studies of omnivores. Vegans showed a substantially lower calcium intake than vegetarians (SMD = -0.57; 95%CI = -0.83 to -0.32; p = <0.0001) and omnivores (SMD = -0.70; 95%CI = -0.95 to -0.59; p < 0.0001), whereas no statistically significant difference in calcium intake was noted between vegetarians and omnivores (SMD = 0.07; 95%CI = -0.04 to 0.19; p = 0.1976). In conclusion, vegans show a lower calcium intake than vegetarians and omnivores. This finding emphasizes the need for vegans to monitor their calcium status.

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.

Sedentary behavior and cancer-an umbrella review and meta-analysis

Several systematic reviews and meta-analyses have summarized the association between sedentary behavior (SB) and cancer. However, the level of evidence and the potential for risk of bias remains unclear. This umbrella review summarized the current data on SB in relation to cancer incidence and mortality, with a particular emphasis on assessing the risk of bias. We searched PubMed, Web of Science and Cochrane Database for systematic reviews and meta-analyses on the association between SB and cancer incidence and mortality. We also searched for recent observational studies not yet included in existing meta-analyses. We re-calculated summary risk estimates for cancer incidence and mortality using random effects models. We included 14 meta-analyses covering 17 different cancer sites from 77 original studies. We found that high SB levels increase the risk for developing ovarian, endometrial, colon, breast, prostate, and rectal cancers, with relative risks of 1.29 (95% confidence interval (CI) = 1.08-1.56), 1.29 (95% CI = 1.16-1.45), 1.25 (95% CI = 1.16-1.33), 1.08 (95% CI = 1.04-1.11), 1.08 (95% CI = 1.00-1.17), and 1.07 (95% CI = 1.01-1.12), respectively. Also, we found an increased risk of cancer mortality of 1.18 (95% CI = 1.09-1.26). Most associations between SB and specific cancer sites were supported by a "suggestive" level of evidence. High levels of SB are associated with increased risk of several types of cancer and increased cancer mortality risk.

How effective and how expensive are interventions to reduce sedentary behavior? An umbrella review and meta-analysis

A reduction in sedentary behavior (SB) can contribute to the prevention of chronic diseases. This is the first umbrella review that summarizes the effectiveness and monetary costs of different types of interventions to reduce SB across all age groups and populations in different settings. We comprehensively searched seven databases for systematic reviews and meta-analyses and conducted an umbrella review of the effects of interventions to reduce SB. Additionally, we performed a meta-analysis of primary studies included in the umbrella review. Furthermore, we analyzed health economic aspects of interventions to reduce SB. We included 40 systematic reviews in our umbrella review, with 136 primary studies suitable for further meta-analyses. We found that interventions targeting the physical environment reduce SB most effectively in the majority of populations and settings. Workplace interventions reduced SB by -89.83 min/day (95% CI -124.58 to -55.09; p ≤ 0.0001). Twenty-two of 169 primary studies (13.0%) contained health economic information. The intervention costs per participant ranged from €0 to €3587. Our findings demonstrate that physical environment interventions most effectively reduce SB in a majority of populations and settings. Health economic information was reported in few studies and was mostly restricted to acquisition costs.

Anthropometric factors and the risk of ovarian cancer: A systematic review and meta-analysis

BACKGROUND

Excess weight is convincingly associated with several cancers, but the association with ovarian cancer is insufficiently clarified, in particular regarding subgroups defined by menopausal status and ovarian cancer histologic type.

AIMS

We carried out a comprehensive systematic review and meta-analysis of overweight and obesity in relation to ovarian cancer with focus on different subgroups.

METHODS AND RESULTS

We searched PubMed and Web of Science for relevant cohort and case-control studies published from inception to June 2021 in English language and using a clear definition of overweight and obesity. We combined maximally adjusted risk estimates using a random effects model. We analyzed data from 15 cohort and 26 case-control studies, including 28 471 ovarian cancer cases. The relative risk of ovarian cancer for overweight and obesity was 1.06 (95% confidence interval [CI] = 1.00-1.12) and 1.19 (95% CI = 1.11-1.28), respectively. Among premenopausal women, increased ovarian cancer risk was noted for overweight (RR 1.34; 95% CI = 1.03-1.75) and obesity (RR 1.51; 95% CI = 1.21-1.88). By comparison, among postmenopausal women no statistically significant association was found for overweight (RR 1.00; 95% CI 0.87-1.14) and obesity (RR1.03; 95% CI = 0.82-1.31). Increased risk was found for mucinous (RR 1.44; 95% CI = 1.03-2.01) and clear cell (RR 1.82; 95% CI = 1.11-2.99) ovarian cancer subtypes, but not for serous (RR1.12; 95% CI = 0.84-1.50;) and endometroid subtypes (RR1.24; 95% CI =0.96-1.60).

CONCLUSIONS

Obesity is associated with increased ovarian cancer risk. That relation is largely due to a positive association between adiposity and ovarian cancer among premenopausal but not postmenopausal women and among cases with mucinous and clear cell but not serous or endometrioid histology.

Suicide risk and mortality among patients with cancer

Despite substantial progress in cancer therapy in recent decades, patients with cancer remain at high suicide risk. Data from individual studies have not been comprehensively quantified and specific risk factors are ill-defined. We assessed suicide mortality risk according to cancer prognosis, stage, time since diagnosis, gender, ethnicity, marital status, year of recruitment and geographic region. We searched EMBASE, MEDLINE, PsycINFO, Web of Science, CINAHL and Google Scholar for relevant articles up to February 2021. We used a random effects model, performed meta-regression meta-analysis and assessed heterogeneity and publication bias using I², funnel plots and Egger's and Begg's tests. We performed a systematic review including 62 studies and 46,952,813 patients. To avoid patient sample overlap, the meta-analysis was performed on 28 studies, involving 22,407,690 patients with cancer. Suicide mortality was significantly increased compared with the general population (standardized mortality ratio = 1.85, 95% confidence interval = 1.55-2.20). Risk was strongly related to cancer prognosis, cancer stage, time since diagnosis and geographic region. Patients with cancer, particularly those with specific risk factors, should be closely monitored for suicidality and need specialized care to reduce short- and long-term risks of suicide.

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

BACKGROUND

25-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).

METHOD

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. This article is protected by copyright. All rights reserved.

Understanding the consequences of educational inequalities on periodontitis: Mendelian randomization study

AIM

Higher educational attainment is associated with a lower risk of periodontitis, but the extent to which this association is causal and mediated by intermediate factors is unclear.

METHODS AND MATERIALS

Using summary data from genetic association studies from up to 1.1 million participants of European descent, univariable and multivariable Mendelian randomization analyses were performed to infer the total effect of educational attainment on periodontitis and to estimate the degree to which income, smoking, alcohol consumption, and body mass index mediate the association.

RESULTS

The odds ratio of periodontitis per one standard deviation increment in genetically predicted education was 0.78 (95% CI: 0.68-0.89). The proportions mediated of the total effect of genetically predicted education on periodontitis were 64%, 35%, 15%, and 46% for income, smoking, alcohol consumption, and body mass index, respectively.

CONCLUSIONS

Using a genetic instrumental variable approach, this study triangulated evidence from existing observational epidemiological studies and suggested that higher educational attainment lowers periodontitis risk. Measures to reduce the burden of educational disparities in periodontitis risk may tackle downstream risk factors, particularly income, smoking, and obesity.

Rare variant analysis in eczema identifies exonic variants in DUSP1, NOTCH4 and SLC9A4

Previous genome-wide association studies revealed multiple common variants involved in eczema but the role of rare variants remains to be elucidated. Here, we investigate the role of rare variants in eczema susceptibility. We meta-analyze 21 study populations including 20,016 eczema cases and 380,433 controls. Rare variants are imputed with high accuracy using large population-based reference panels. We identify rare exonic variants in DUSP1, NOTCH4, and SLC9A4 to be associated with eczema. In DUSP1 and NOTCH4 missense variants are predicted to impact conserved functional domains. In addition, five novel common variants at SATB1-AS1/KCNH8, TRIB1/LINC00861, ZBTB1, TBX21/OSBPL7, and CSF2RB are discovered. While genes prioritized based on rare variants are significantly up-regulated in the skin, common variants point to immune cell function. Over 20% of the single nucleotide variant-based heritability is attributable to rare and low-frequency variants. The identified rare/low-frequency variants located in functional protein domains point to promising targets for novel therapeutic approaches to eczema.

Genetic studies of eczema to date have mostly explored common genetic variation. Here, the authors perform a large meta-analysis for common and rare variants and discover 8 loci associated with eczema. Over 20% of the heritability of the condition is attributable to rare variants.

Cannabis use does not impact on type 2 diabetes: A two-sample Mendelian randomization study

Cannabis has effects on the insulin/glucose metabolism. As the use of cannabis and the prevalence of type 2 diabetes increase worldwide, it is important to examine the effect of cannabis on the risk of diabetes. We conducted a Mendelian randomization (MR) study by using 19 single-nucleotide polymorphisms (SNPs) as instrumental variables for lifetime cannabis use and 14 SNPs to instrument cannabis use disorder and linking these to type 2 diabetes risk using genome-wide association study data (lifetime cannabis use [N = 184,765]; cannabis use disorder [2387 cases/48,985 controls], type 2 diabetes [74,124 cases/824,006 controls]). The MR analysis suggested no effect of lifetime cannabis use (inverse-variance weighted odds ratio [95% confidence interval] = 1.00 [0.93-1.09], P value = 0.935) and cannabis use disorder (OR = 1.03 [0.99-1.08]) on type 2 diabetes. Sensitivity analysis to assess potential pleiotropy led to no substantive change in the estimates. This study adds to the evidence base that cannabis use does not play a causal role in type 2 diabetes.

Body Fat Distribution and Risk of Breast, Endometrial, and Ovarian Cancer: A Two-Sample Mendelian Randomization Study

Simple Summary

The causal impact of body fat distribution on female-specific cancers is largely unknown. For the first time we used a two-sample multivariable Mendelian randomization (MR) approach to elucidate the role and causal relations of body composition assessed by segmental bioelectrical impedance analysis on the risks of breast, endometrial and ovarian cancers and their subtypes. We found that abdominal fat content increases the risk for ovarian cancer and its endometrioid and clear cell subtypes independent of overall fat content. General adiposity has a protective effect on risk of breast cancer and its ER- and ER+ subtypes but increases the risk for endometrial cancer, ovarian cancer, and the endometrioid ovarian cancer subtype. This study extends the literature by addressing specifically the causal role of visceral fat on female-specific cancers.

Abstract

Background: Mounting evidence shows that adiposity increases female-specific cancer risk, but the role of body fat distribution is less clear. We used a two-sample Mendelian randomization (MR) approach to elucidate causal relations of body fat distribution to the risks of breast, endometrial and ovarian cancers and their subtypes. Methods: Body composition was assessed using segmental bioelectrical impedance analysis, yielding trunk, arm, and leg fat ratios (TFR, AFR, LFR) and BMI including 195,043 and 434,794 European women, respectively. The sample sizes for the outcomes ranged between 58,396 and 228,951. Causal effects were estimated per one standard deviation increment in the respective exposure within the radial regression framework. Robust sensitivity analyses were performed to verify MR assumptions. In a multivariable MR setting, the proportion of risk attributable to overall and abdominal fat content was assessed. Results: TFR, which represents abdominal fat content, was associated with ovarian cancer and its clear cell and endometrioid histotypes independent of overall fat content. BMI was inversely associated with breast cancer and its ER− and ER+ subtypes, but positively with endometrial cancer and ovarian cancer, including its endometrioid histotype. These estimates were confirmed using AFR as proxy for overall body fat. Conclusions: Visceral adiposity seems to be a driver of elevated ovarian cancer risk, particularly of the endometrioid and clear cell ovarian cancer histotypes. General adiposity decreases the risk of breast cancer but increases the risk of endometrial and ovarian cancer.

Physical activity, sedentary behavior and risk of coronary artery disease, myocardial infarction and ischemic stroke: a two-sample Mendelian randomization study

AIMS

Observational evidence suggests that physical activity (PA) is inversely and sedentarism positively related with cardiovascular disease risk. We performed a two-sample Mendelian randomization (MR) analysis to examine whether genetically predicted PA and sedentary behavior are related to coronary artery disease, myocardial infarction, and ischemic stroke.

METHODS AND RESULTS

We used single nucleotide polymorphisms (SNPs) associated with self-reported moderate to vigorous PA (n = 17), accelerometer based PA (n = 7) and accelerometer fraction of accelerations > 425 milli-gravities (n = 7) as well as sedentary behavior (n = 6) in the UK Biobank as instrumental variables in a two sample MR approach to assess whether these exposures are related to coronary artery disease and myocardial infarction in the CARDIoGRAMplusC4D genome-wide association study (GWAS) or ischemic stroke in the MEGASTROKE GWAS. The study population included 42,096 cases of coronary artery disease (99,121 controls), 27,509 cases of myocardial infarction (99,121 controls), and 34,217 cases of ischemic stroke (404,630 controls). We found no associations between genetically predicted self-reported moderate to vigorous PA, accelerometer-based PA or accelerometer fraction of accelerations > 425 milli-gravities as well as sedentary behavior with coronary artery disease, myocardial infarction, and ischemic stroke.

CONCLUSIONS

These results do not support a causal relationship between PA and sedentary behavior with risk of coronary artery disease, myocardial infarction, and ischemic stroke. Hence, previous observational studies may have been biased.

Testing the association between tobacco smoking, alcohol consumption, and risk of periodontitis: A Mendelian randomization study

AIM

To investigate the associations of tobacco smoking and alcohol consumption with periodontitis using Mendelian randomization (MR) analysis.

MATERIALS AND METHODS

We used 17 single nucleotide polymorphisms (SNPs) as instrumental variables (IVs) for the number of cigarettes per day from a genome-wide association study (GWAS) of 337,334 individuals, 109 SNPs for a lifetime smoking index from GWAS of 462,690 participants, and 33 SNPs for the number of drinks per week from GWAS of 941,280 individuals. The periodontitis GWAS included 12,289 cases and 22,326 controls. Wald ratios were obtained by dividing the SNP-periodontitis effects by SNP-exposure effects and pooled using an inverse-variance weighted model.

RESULTS

Genetic liabilities for higher number of cigarettes per day (odds ratio [OR] per one standard deviation (1SD) increment = 1.56; 95% CI: 1.18-2.07, p-value = .0018, Q-value = .0054), lifetime smoking index (OR per 1SD = 1.26; 95% CI: 1.04-1.53, p-value = .0161, Q-value = .0242), and drinks per week (OR per 1SD = 1.41; 95% CI: 1.04-1.90, p-value = .0265, Q-value = .0265) were associated with increased odds of periodontitis. Estimates were consistent across robust and multivariable MR analyses.

CONCLUSIONS

The findings of this MR analysis suggest an association between tobacco smoking and alcohol consumption with periodontitis.

Cannabis Use, Pulmonary Function, and Lung Cancer Susceptibility: A Mendelian Randomization Study

INTRODUCTION

Because of widespread use, understanding the pulmonary effects of cannabis use is important; but its role independent from tobacco smoking is yet to be elucidated. We used Mendelian randomization (MR) to assess the effect of genetic liability to lifetime cannabis use and cannabis use disorder on pulmonary function and lung cancer.

METHODS

We used four single nucleotide polymorphisms associated with lifetime cannabis use (p value <5 × 10-8) from a genome-wide association study (GWAS) of 184,765 individuals of European descent from the International Cannabis Consortium, 23andme, and U.K. Biobank as instrumental variables. Seven single nucleotide polymorphisms (p value <5 × 10-8) were selected as instruments for cannabis use disorder from a GWAS meta-analysis of 17,068 European ancestry cases and 357,219 controls of European descent from Psychiatric Genomics Consortium Substance Use Disorders working group, Lundbeck Foundation Initiative for Integrative PsychiatricResearch, and deCode. To assess lung function, GWAS included 79,055 study participants of the SpiroMeta Consortium, and for lung cancer GWAS from the International Lung Cancer Consortium contained 29,266 cases and 56,450 controls.

RESULTS

MR revealed that genetic liability to lifetime cannabis use was associated with increased risk of squamous cell carcinoma (OR = 1.22, 95%, confidence interval = 1.07-1.39, p value = 0.003, q value = 0.025). Pleiotropy-robust methods and positive and negative control analyses did not indicate bias in the primary analysis.

CONCLUSIONS

The findings of this MR analysis suggest evidence for a potential causal association between genetic liability for cannabis use and the risk of squamous cell carcinoma. Triangulating MR and observational studies and addressing orthogonal sources of bias are necessary to confirm this finding.

Periodontitis and pulmonary function: a Mendelian randomization study

Objectives

Observational research suggests that periodontitis affects pulmonary function; however, observational studies are subject to confounding and reverse causation, making causal inference and the direction of these associations difficult. We used Mendelian randomization (MR) to assess the potential causal association between genetic liability to periodontitis and pulmonary function.

Materials and methods

We used six single-nucleotide polymorphisms (SNPs) associated with periodontitis (P < 5 × 10⁻⁶) from a genome-wide association study (GWAS) of 17,353 European descent periodontitis cases and 28,210 controls from the GeneLifestyle Interactions in Dental Endpoints consortium and the UK Biobank, and related these to SNPs from a lung function GWAS including 79,055 study participants of the SpiroMeta Consortium.

Results

MR analysis suggested no effect of periodontitis on the ratio of forced expiratory volume in one second to lower forced vital capacity (standard deviation increment in outcome per doubling of the odds of the exposure (95% confidence interval) =  − 0.004 (− 0.028; 0.020)). Replication analysis using genetic instruments from two different GWAS and sensitivity analyses to address potential pleiotropy led to no substantial changes in estimates.

Conclusions

Collectively, these findings do not support a relationship between genetic liability for periodontitis and pulmonary function.

Clinical relevance

Periodontitis does not seem to be a risk factor for worsening of pulmonary function.

Host traits, lifestyle and environment are associated with human skin bacteria

BACKGROUND

The human skin offers diverse ecosystems for microbial symbionts. However, the factors shaping skin-microbiome interactions are still insufficiently characterized. This contrasts with the broader knowledge about factors influencing gut microbiota.

OBJECTIVES

We aimed to investigate major patterns of association of host traits, lifestyle and environmental factors with skin bacteria in two German populations.

METHODS

This is a cross-sectional study with 647 participants from two population-based German cohorts, PopGen (n = 294) and KORA FF4 (n = 353), totalling 1794 skin samples. The V1-V2 regions of the 16S ribosomal RNA (rRNA) gene were sequenced. Associations were tested with two bacterial levels, community (beta diversity) and 16S rRNA gene amplicon sequence variants (ASVs).

RESULTS

We validated known associations of the skin microbiota with skin microenvironment, age, body mass index and sex. These factors were associated with beta diversity and abundance of ASVs in PopGen, which was largely replicated in KORA FF4. Most intriguingly, dietary macronutrients and total dietary energy were associated with several ASVs. ASVs were also associated with smoking, alcohol consumption, skin pH, skin type, transepidermal water loss, education and several environmental exposures, including hours spent outdoors. Associated ASVs included members of the genera Propionibacterium, Corynebacterium and Staphylococcus.

CONCLUSIONS

We expand the current understanding of factors associated with the skin bacterial community. We show the association of diet with skin bacteria. Finally, we hypothesize that the skin microenvironment and host physiology would shape the skin bacterial community to a greater extent compared with a single skin physiological feature, lifestyle and environmental exposure.

Relationship between atopic dermatitis, depression and anxiety: a two-sample Mendelian randomization study

BACKGROUND

Growing evidence suggests that atopic dermatitis (AD) is associated with an increased risk of depressive disorders and anxiety. However, existing studies were observational and may have uncovered correlations but could not easily disentangle noncausal or reverse-causal associations because these associations could be confounded and may not reflect true causal relationships.

OBJECTIVES

To examine, in a two-sample Mendelian randomization study, the potential effect of AD on the risk of depressive disorders and anxiety.

METHODS

Genetic instruments from the largest available genome-wide association study (GWAS) for AD (10 788 cases and 30 047 controls) were used to investigate the relationship to broad depression (170 756 cases and 329 443 controls), major depressive disorder (MDD; 30 603 cases and 143 916 controls) and anxiety (5580 cases and 11 730 controls). A set of complementary approaches were carried out to assess horizontal pleiotropy and related potential caveats occurring in MR studies.

RESULTS

We observed no causal impact of AD on the risk of depressive disorders and anxiety, with close-to-zero effect estimates. The inverse weighted method revealed no associations of AD on broad depression [odds ratio (OR) 1·014; P = 0·431], probable MDD (OR 1·002; P = 0·568), International Classification of Diseases, Ninth/Tenth Revision-based MDD (OR 1·001; P = 0·466) or anxiety (OR 1·097; P = 0·180).

CONCLUSIONS

This MR study does not support a causal effect of AD on depression and anxiety.

Physical activity and risk of Alzheimer disease: A 2-sample mendelian randomization study

OBJECTIVE

Evidence from observational studies for the effect of physical activity on the risk of Alzheimer disease (AD) is inconclusive. We performed a 2-sample mendelian randomization analysis to examine whether physical activity is protective for AD.

METHODS

Summary data of genome-wide association studies on physical activity and AD were used. The primary study population included 21,982 patients with AD and 41,944 cognitively normal controls. Eight single nucleotide polymorphisms (SNPs) known at p < 5 × 10-8 to be associated with average accelerations and 8 SNPs associated at p < 5 × 10-7 with vigorous physical activity (fraction of accelerations >425 milligravities) served as instrumental variables.

RESULTS

There was no association between genetically predicted average accelerations with the risk of AD (inverse variance weighted odds ratio [OR] per SD increment: 1.03, 95% confidence interval 0.97-1.10, p = 0.332). Genetic liability for fraction of accelerations >425 milligravities was unrelated to AD risk.

CONCLUSION

The present study does not support a causal association between physical activity and risk of AD.

Stratum corneum lipidomics analysis reveals altered ceramide profile in atopic dermatitis patients across body sites with correlated changes in skin microbiome

BACKGROUND

Atopic dermatitis (AD) is driven by the interplay between a dysfunctional epidermal barrier and a skewed cutaneous immune dysregulation. As part of the complex skin barrier dysfunction, abnormalities in lipid organization and microbiome composition have been described. We set out to systematically investigate the composition of the stratum corneum lipidome, skin microbiome and skin physiology parameters at three different body sites in patients with AD and healthy volunteers.

METHODS

We analysed tape strips from different body areas obtained from 10 adults with AD and 10 healthy volunteers matched for FLG mutation status for 361 skin lipid species using the Metabolon mass spectrometry platform. 16S rRNA data were available from all probands.

RESULTS

Our study showed that the lipid composition differs significantly between body sites and between AD patients and healthy individuals. Ceramide species NS was significantly higher in AD patients compared to healthy volunteers and was also higher in AD patients with a FLG mutation compared to AD patients without a FLG mutation. The correlation analysis of skin lipid alterations with the microbiome showed that Staphylococcus colonization in AD is positively correlated with ceramide subspecies AS, ADS, NS and NDS.

CONCLUSION

This is the first study to reveal site-specific lipid alterations and correlations with the skin microbiome in AD.

[Occurrence of bronchial asthma and age at initial asthma diagnosis-first results of the German National Cohort]

BACKGROUND

Asthma is one of the most common chronic diseases in both children and adults. Asthma first occurring in adulthood (adult-onset asthma, AOA) is associated with poorer prognosis compared to childhood-onset asthma (COA), which urgently calls for more research in this area. The aim of this work was to analyze the data on asthma collected in the German National Cohort and compare it with the German Health Interview and Examination Survey for Adults (DEGS), in particular regarding AOA.

MATERIAL AND METHODS

Our analysis was based on the dataset of the main questionnaire at mid-term of the German National Cohort baseline examination, comprising 101,723 participants. Variables considered in the analyses were self-reported diagnosis of asthma, age at first diagnosis, asthma treatment in the past 12 months, age, and sex.

RESULTS

In the midterm dataset, 8.7% of women and 7.0% of men in the German National Cohort reported that they had ever been diagnosed with asthma. Approximately one third of participants with asthma received their initial diagnosis before their 18th birthday. COA affected 2.2% of women and 2.8% of men, whereas AOA affected 6.5% of women and 4.2% of men. During the previous 12 months, 33% of COA cases and 60% of AOA cases were medically treated.

CONCLUSION

The proportion of persons affected by asthma in the German National Cohort, as well as observed patterns regarding age and gender, corresponds to other data sources such as DEGS. However, in our analysis, the proportion of individuals with AOA was higher than described in the literature. The increase in cumulative asthma diagnoses with age is markedly steeper in younger participants, indicating a rising trend over time.

[Anthropometric measures in the German National Cohort-more than weight and height]

High levels of adiposity in the population have a major impact on various diseases, but previous epidemiologic studies have largely been restricted to simple anthropometric measures such as the body mass index (BMI), an imperfect predictor of disease risk. There is a critical need for the use of improved measures of relative weight and body composition in large-scale, population-based research.The current article presents initial descriptive results of body composition and fat distribution based on the midterm baseline dataset of the German National Cohort, which included 101,817 participants who were examined in 18 study centers in Germany between March 2014 and March 2017. The anthropometric measures encompassed body weight, height, waist and hip circumference, bioelectrical impedance analysis (BIA), sonography of abdominal adipose tissue, 3D-body scanning, and magnetic resonance imaging.BMI analyses showed that 46.2% of men and 29.7% of women were overweight and 23.5% of men and 21.2% of women were obese. On average, women in almost all age groups demonstrated more subcutaneous adipose tissue layer thickness than men. The mean values of visceral adipose tissue layer thickness, on the other hand, were higher among men than among women in all age groups and increased continuously across age groups in both sexes.The comprehensive assessment of body composition and fat distribution provides novel future opportunities for detailed epidemiologic analyses of overweight and adiposity in relation to the development of chronic diseases.