Genetically predicted high IGF-1 levels showed protective effects on COVID-19 susceptibility and hospitalization: a Mendelian randomisation study with data from 60 studies across 25 countries.

Background: Epidemiological studies observed gender differences in COVID-19 outcomes, however, whether sex hormone plays a causal in COVID-19 risk remains unclear. This study aimed to examine associations of sex hormone, sex hormones-binding globulin (SHBG), insulin-like growth factor-1 (IGF-1), and COVID-19 risk. Methods: Two-sample Mendelian randomization (TSMR) study was performed to explore the causal associations between testosterone, estrogen, SHBG, IGF-1, and the risk of COVID-19 (susceptibility, hospitalization, and severity) using genome-wide association study (GWAS) summary level data from the COVID-19 Host Genetics Initiative (N=1,348,701). Random-effects inverse variance weighted (IVW) MR approach was used as the primary MR method and the weighted median, MR-Egger, and MR Pleiotropy RESidual Sum and Outlier (MR-PRESSO) test were conducted as sensitivity analyses. Results: Higher genetically predicted IGF-1 levels have nominally significant association with reduced risk of COVID-19 susceptibility and hospitalization. For one standard deviation increase in genetically predicted IGF-1 levels, the odds ratio was 0.77 (95% confidence interval [CI], 0.61-0.97, p=0.027) for COVID-19 susceptibility, 0.62 (95% CI: 0.25-0.51, p=0.018) for COVID-19 hospitalization, and 0.85 (95% CI: 0.52-1.38, p=0.513) for COVID-19 severity. There was no evidence that testosterone, estrogen, and SHBG are associated with the risk of COVID-19 susceptibility, hospitalization, and severity in either overall or sex-stratified TSMR analysis. Conclusions: Our study indicated that genetically predicted high IGF-1 levels were associated with decrease the risk of COVID-19 susceptibility and hospitalization, but these associations did not survive the Bonferroni correction of multiple testing. Further studies are needed to validate the findings and explore whether IGF-1 could be a potential intervention target to reduce COVID-19 risk. Funding: We acknowledge support from NSFC (LR22H260001), CRUK (C31250/A22804), SHLF (Hjärt-Lungfonden, 20210351), VR (Vetenskapsrådet, 2019-00977), and SCI (Cancerfonden).

A Mendelian randomization study of genetic predisposition to autoimmune diseases and COVID-19.

Autoimmune diseases and coronavirus disease 2019 (COVID-19) share many similarities. Concerns have arisen that autoimmune diseases may increase the susceptibility and severity of COVID-19. We used Mendelian randomization to investigate whether liability to autoimmune diseases is related to COVID-19 susceptibility and severity. Genetic instruments for 8 autoimmune diseases, including type 1 diabetes mellitus, rheumatoid arthritis, systemic lupus erythematosus, psoriasis, multiple sclerosis, primary sclerosing cholangitis, primary biliary cirrhosis and juvenile idiopathic arthritis, were obtained from published genome-wide association studies. Two-sample Mendelian randomization analyses of the associations of liability to each autoimmune disease with COVID-19 infection, hospitalized COVID-19, and very severe COVID-19 were performed using the latest publicly available genome-wide association study for COVID-19. Genetic liability to each of the autoimmune diseases was largely not associated with COVID-19 infection, hospitalized COVID-19, or very severe COVID-19 after accounting for multiple comparison. Sensitivity analysis excluding genetic variants in the human leukocyte antigen gene, which has an important role in the immune response, showed similar results. The autoimmune diseases examined were largely not genetically associated with the susceptibility or severity of COVID-19. Further investigations are warranted.

Mendelian Randomization Studies on Nutritional Factors and Health Outcomes.

Poor diet is a leading cause of morbidity and mortality [...].

Long-term cadmium exposure and fractures, cardiovascular disease, and mortality in a prospective cohort of women.

BACKGROUND: Cadmium (Cd) is a toxic metal, which the non-smoking population is mainly exposed to through diet. Current health-based guidance values are based on renal toxicity; however, emerging evidence suggests that bone and the cardiovascular system might be more sensitive to Cd exposure. OBJECTIVE: To assess the association of urinary Cd (U-Cd) with incidence of fractures, myocardial infarction, heart failure, ischemic stroke and mortality in postmenopausal women. METHODS: We used data from 4024 women, aged 56-85 in the population-based prospective Swedish Mammography Cohort-Clinical. U-Cd was measured by ICP-MS at baseline (2004-2009) and categorized into tertiles. Incident cases of the outcomes were ascertained via register linkage through 2019. Multivariable-adjusted hazard ratios (HR) and 95% confidence intervals (CI) were estimated using Cox regression. RESULTS: The median U-Cd at baseline was 0.33 µg/g creatinine (cr) (5-95 percentiles 0.15-0.77). We ascertained the following incident cases: 903 first fracture of any type, 149 myocardial infarction, 174 heart failure, 162 ischemic stroke and 545 total deaths during the approximately 11 years of follow-up. U-Cd was dose-dependently associated with risk of any fracture (HR: 1.20, 95% CI: 1.01 to 1.43, ptrend: 0.04) and all-cause mortality (HR: 1.38, 95% CI: 1.10 to 1.74, ptrend: <0.01) when comparing the highest tertile of U-Cd (median 0.54 µg/g cr) with the lowest (median 0.20 µg/g cr). No clear associations were observed for myocardial infarction, heart failure or stroke. DISCUSSION: Long-term Cd exposure might be associated with risk of fractures and all-cause mortality at lower levels than previously suggested.

ACE inhibition and cardiometabolic risk factors, lung ACE2 and TMPRSS2 gene expression, and plasma ACE2 levels: a Mendelian randomization study.

Angiotensin-converting enzyme 2 (ACE2) and serine protease TMPRSS2 have been implicated in cell entry for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for coronavirus disease 2019 (COVID-19). The expression of ACE2 and TMPRSS2 in the lung epithelium might have implications for the risk of SARS-CoV-2 infection and severity of COVID-19. We use human genetic variants that proxy angiotensin-converting enzyme (ACE) inhibitor drug effects and cardiovascular risk factors to investigate whether these exposures affect lung ACE2 and TMPRSS2 gene expression and circulating ACE2 levels. We observed no consistent evidence of an association of genetically predicted serum ACE levels with any of our outcomes. There was weak evidence for an association of genetically predicted serum ACE levels with ACE2 gene expression in the Lung eQTL Consortium (p = 0.014), but this finding did not replicate. There was evidence of a positive association of genetic liability to type 2 diabetes mellitus with lung ACE2 gene expression in the Gene-Tissue Expression (GTEx) study (p = 4 × 10-4) and with circulating plasma ACE2 levels in the INTERVAL study (p = 0.03), but not with lung ACE2 expression in the Lung eQTL Consortium study (p = 0.68). There were no associations of genetically proxied liability to the other cardiometabolic traits with any outcome. This study does not provide consistent evidence to support an effect of serum ACE levels (as a proxy for ACE inhibitors) or cardiometabolic risk factors on lung ACE2 and TMPRSS2 expression or plasma ACE2 levels.