A genome-wide association study of susceptibility to upper urinary tract infections.

BACKGROUND: Our goal was to identify genetic and modifiable risk factors for upper urinary tract infections (UTIs). METHODS: We used data from UK Biobank, The Trøndelag Health Study (HUNT), and Michigan Genomics Initiative (MGI) to conduct genome-wide association studies (GWASs) and sex-stratified analyses on upper UTI. Mendelian randomization (MR) analyses were conducted to examine potential causal relationships between cardiometabolic risk factors and upper UTIs. RESULTS: One genome-wide significant (P ≤ 5E-08) locus was associated with the susceptibility to upper UTI, located near TSN in the female-only analysis. Additionally, we identified suggestive (P ≤ 5E-06) loci near DNAI3 for the females, SCAMP1-AS1 for the males, and near TSN, LINC00603, and HLA-DQA2 for both sexes. In MR analyses, higher genetically predicted lifetime smoking scores were associated with an increased risk of developing upper UTI for females and both sexes (OR of 4.84, P = 4.50E-06 and OR of 2.79, P = 3.02E-05, respectively). CONCLUSIONS: We found that genetic variants near TSN was associated with the risk of upper UTIs among females. In addition, we found several genetic loci with suggestive associations with the risk of upper UTIs. Finally, MR analyses found smoking to be a potential causal risk factor for upper UTIs.

Chronic kidney disease and risk of bloodstream infections and sepsis: a 17-year follow-up of the population-based Trøndelag Health Study in Norway.

PURPOSE: Bloodstream infections (BSI) and sepsis are important causes of hospitalization, loss of health, and death globally. Targetable risk factors need to be identified to improve prevention and treatment. In this study, we aimed to evaluate the association of chronic kidney disease (CKD) and risk of and mortality from BSI and sepsis in the general population during a 22-year period. METHODS: We conducted a prospective cohort study among participants in the population-based Norwegian HUNT Study, where 68,438 participated. The median follow-up time was 17.4 years. The exposures were estimated glomerular filtration rate (eGFR) and albumin-creatinine ratio (ACR) in urine. The outcomes were hazard ratios (HR) of hospital admission or death due to BSI or sepsis. The associations were adjusted for age, sex, diabetes, obesity, systolic blood pressure, smoking status, and cardiovascular disease. RESULTS: Participants with eGFR < 30 ml/min/1.732 had HR 3.35 for BSI (95% confidence intervals (CI) 2.12-5.3) and HR 2.94 for sepsis (95% CI 1.82-4.8) compared to normal eGFR (≥ 90 ml/min/1.732). HRs of death from BSI and sepsis were 4.2 (95% CI 1.71-10.4) and 4.1 (95% CI 1.88-8.9), respectively. Participants with severely increased albuminuria (ACR > 30 mg/mmol) had HR 3.60 for BSI (95% CI 2.30-5.6) and 3.14 for sepsis (95% CI 1.94-5.1) compared to normal albumin excretion (ACR < 3 mg/mmol). HRs of death were 2.67 (95% CI 0.82-8.7) and 2.16 (95% CI 0.78-6.0), respectively. CONCLUSION: In this large population-based cohort study, CKD was clearly associated with an increased risk of BSI and sepsis and related death.

Pharmacologic and Genetic Downregulation of Proprotein Convertase Subtilisin/Kexin Type 9 and Survival From Sepsis.

OBJECTIVES: Treatments that prevent sepsis complications are needed. Circulating lipid and protein assemblies-lipoproteins play critical roles in clearing pathogens from the bloodstream. We investigated whether early inhibition of proprotein convertase subtilisin/kexin type 9 (PCSK9) may accelerate bloodstream clearance of immunogenic bacterial lipids and improve sepsis outcomes. DESIGN: Genetic and clinical epidemiology, and experimental models. SETTING: Human genetics cohorts, secondary analysis of a phase 3 randomized clinical trial enrolling patients with cardiovascular disease (Evaluation of Cardiovascular Outcomes After an Acute Coronary Syndrome During Treatment With Alirocumab [ODYSSEY OUTCOMES]; NCT01663402), and experimental murine models of sepsis. PATIENTS OR SUBJECTS: Nine human cohorts with sepsis (total n = 12,514) were assessed for an association between sepsis mortality and PCSK9 loss-of-function (LOF) variants. Incident or fatal sepsis rates were evaluated among 18,884 participants in a post hoc analysis of ODYSSEY OUTCOMES. C57BI/6J mice were used in Pseudomonas aeruginosa and Staphylococcus aureus bacteremia sepsis models, and in lipopolysaccharide-induced animal models. INTERVENTIONS: Observational human cohort studies used genetic PCSK9 LOF variants as instrumental variables. ODYSSEY OUTCOMES participants were randomized to alirocumab or placebo. Mice were administered alirocumab, a PCSK9 inhibitor, at 5 mg/kg or 25 mg/kg subcutaneously, or isotype-matched control, 48 hours prior to the induction of bacterial sepsis. Mice did not receive other treatments for sepsis. MEASUREMENTS AND MAIN RESULTS: Across human cohort studies, the effect estimate for 28-day mortality after sepsis diagnosis associated with genetic PCSK9 LOF was odds ratio = 0.86 (95% CI, 0.67-1.10; p = 0.24). A significant association was present in antibiotic-treated patients. In ODYSSEY OUTCOMES, sepsis frequency and mortality were infrequent and did not significantly differ by group, although both were numerically lower with alirocumab vs. placebo (relative risk of death from sepsis for alirocumab vs. placebo, 0.62; 95% CI, 0.32-1.20; p = 0.15). Mice treated with alirocumab had lower endotoxin levels and improved survival. CONCLUSIONS: PCSK9 inhibition may improve clinical outcomes in sepsis in preventive, pretreatment settings.

Gestational age at birth and hospitalisations for infections among individuals aged 0-50 years in Norway: a longitudinal, register-based, cohort study.

Background: Preterm birth is associated with increased risk of childhood infections. Whether this risk persists into adulthood is unknown and limited information is available on risk patterns across the full range of gestational ages. Methods: In this longitudinal, register-based, cohort study, we linked individual-level data on all individuals born in Norway (January 01, 1967-December 31, 2016) to nationwide hospital data (January 01, 2008-December 31, 2017). Gestational age was categorised as 23-27, 28-31, 32-33, 34-36, 37-38, 39-41, and 42-44 completed weeks. The analyses were stratified by age at follow-up: 0-11 months and 1-5, 6-14, 15-29, and 30-50 years. The primary outcome was hospitalisation due to any infectious disease, with major infectious disease groups as secondary outcomes. Adjusted hospitalisation rate ratios (RRs) for any infection and infectious disease groups were estimated using negative binomial regression. Models were adjusted for year of birth, maternal age at birth, parity, and sex, and included an offset parameter adjusted for person-time at risk. Findings: Among 2,695,830 individuals with 313,940 hospitalisations for infections, we found a pattern of higher hospitalisation risk in lower gestational age groups, which was the strongest in childhood but still evident in adulthood. Comparing those born very preterm (28-31) and late preterm (34-36) to full-term (39-41 weeks), RRs (95% confidence interval) for hospitalisation for any infectious disease at ages 1-5 were 3.3 (3.0-3.7) and 1.7 (1.6-1.8), respectively. At 30-50 years, the corresponding estimates were 1.4 (1.2-1.7) and 1.2 (1.1-1.3). The patterns were similar for the infectious disease groups, including bacterial and viral infections, respiratory tract infections (RTIs), and infections not attributable to RTIs. Interpretation: Increasing risk of hospitalisations for infections in lower gestational age groups was most prominent in children but still evident in adolescents and adults. Possible mechanisms and groups that could benefit from vaccinations and other prevention strategies should be investigated. Funding: St. Olav's University Hospital and Norwegian University of Science and Technology, Norwegian Research Council, Liaison Committee for education, research and innovation in Central Norway, European Commission, Academy of Finland, Sigrid Jusélius Foundation, Foundation for Pediatric Research, and Signe and Ane Gyllenberg Foundation.

Trends in mortality after a sepsis hospitalization: a nationwide prospective registry study from 2008 to 2021.

BACKGROUND: Few studies have reported on mortality beyond one year after sepsis. We aim to describe trends in short- and long-term mortality among patients admitted with sepsis, and to describe the association between clinical characteristics and mortality for improved monitoring, treatment and prognosis. METHODS: Patients ≥ 18 years admitted to all Norwegian hospitals (2008-2021) with a first sepsis episode were identified using Norwegian Patient Registry and International Classification of Diseases 10th Revision codes. Sepsis was classified as implicit (known infection site plus organ dysfunction), explicit (unknown infection site), or COVID-19-related sepsis. The outcome was all-cause mortality. We describe age-standardized 30-day, 90-day, 1-, 5- and 10-year mortality for each admission year and estimated the annual percentage change with 95% confidence interval (CI). The association between clinical characteristics and all-cause mortality is reported as hazard ratios (HRs) adjusted for age, sex and calendar year in Cox regression. RESULTS: The study included 222,832 patients, of whom 127,059 (57.1%) had implicit, 92,928 (41.7%) had explicit, and 2,845 (1.3%) had COVID-19-related sepsis (data from 2020 and 2021). Trends in overall age-standardized 30-day, 90-day, 1- and 5-year mortality decreased by 0.29 (95% CI - 0.39 to - 0.19), 0.43 (95% CI - 0.56 to - 0.29), 0.61 (95% CI - 0.73 to - 0.49) and 0.66 (95% CI - 0.84 to - 0.48) percent per year, respectively. The decrease was observed for all infections sites but was largest among patients with respiratory tract infections. Implicit, explicit and COVID-19-related sepsis had largely similar overall mortality, with explicit sepsis having an adjusted HR of 0.980 (95% CI 0.969 to 0.991) and COVID-19-related sepsis an adjusted HR of 0.916 (95% CI 0.836 to 1.003) compared to implicit sepsis. Patients with respiratory tract infections have somewhat higher mortality than those with other infection sites. Number of comorbidities was positively associated with mortality, but mortality varied considerably between different comorbidities. Similarly, number of acute organ dysfunctions was strongly associated with mortality, whereas the risk varied for each type of organ dysfunction. CONCLUSION: Overall mortality has declined over the past 14 years among patients with a first sepsis admission. Comorbidity, site of infection, and acute organ dysfunction are patient characteristics that are associated with mortality. This could inform health care workers and raise the awareness toward subgroups of patients that needs particular attention to improve long-term mortality.

Long-term temporal trends in incidence rate and case fatality of sepsis and COVID-19-related sepsis in Norwegian hospitals, 2008-2021: a nationwide registry study.

OBJECTIVES: To estimate temporal trends in incidence rate (IR) and case fatality during a 14-year period from 2008 to 2021, and to assess possible shifts in these trends during the COVID-19 pandemic. SETTING: All Norwegian hospitals 2008-2021. PARTICIPANTS: 317 705 patients ≥18 year with a sepsis International Classification of Diseases 10th revision code retrieved from The Norwegian Patient Registry. PRIMARY AND SECONDARY MEASURES: Annual age-standardised IRs with 95% CIs. Poisson regression was used to estimate changes in IRs across time, and logistic regression was used to estimate ORs for in-hospital death. RESULTS: Among 12 619 803 adult hospitalisations, a total of 317 705 (2.5%) hospitalisations in 222 832 (70.0%) unique patients met the sepsis criteria. The overall age-standardised IR of a first sepsis admission was 246/100 000 (95% CI 245 to 247), whereas the age-standardised IR of all sepsis admissions was 352/100 000 (95% CI 351 to 354). In the period 2009-2019, the annual IR for a first sepsis episode was stable (IR ratio (IRR) per year, 0.999; 95% CI 0.994 to 1.004), whereas for recurrent sepsis the IR increased (annual IRR, 1.048; 95% CI 1.037 to 1.059). During the COVID-19 pandemic, the IRR for a first sepsis was 0.877 (95% CI 0.829 to 0.927) in 2020 and 0.929 (95% CI 0.870 to 0.992) in 2021, and for all sepsis it was 0.870 (95% CI 0.810 to 0.935) in 2020 and 0.908 (95% CI 0.840 to 0.980) in 2021, compared with the previous 11-year period. Case fatality among first sepsis admissions declined in the period 2009-2019 (annual OR 0.954 (95% CI 0.950 to 0.958)), whereas case fatality increased during the COVID-19 pandemic in 2020 (OR 1.061 (95% CI 1.001 to 1.124) and in 2021 (OR 1.164 (95% CI 1.098 to 1.233)). CONCLUSION: The overall IR of sepsis increased from 2009 to 2019, due to an increasing IR of recurrent sepsis, and indicates that sepsis awareness with updated guidelines and education must continue.

Circulating levels of micronutrients and risk of infections: a Mendelian randomization study.

BACKGROUND: Micronutrients play an essential role at every stage of the immune response, and deficiencies can therefore lead to increased susceptibility to infections. Previous observational studies and randomized controlled trials of micronutrients and infections are limited. We performed Mendelian randomization (MR) analyses to evaluate the effect of blood levels of eight micronutrients (copper, iron, selenium, zinc, beta-carotene, vitamin B12, vitamin C, and vitamin D) on the risk of three infections (gastrointestinal infections, pneumonia, and urinary tract infections). METHODS: Two-sample MR was conducted using publicly available summary statistics from independent cohorts of European ancestry. For the three infections, we used data from UK Biobank and FinnGen. Inverse variance-weighted MR analyses were performed, together with a range of sensitivity analyses. The threshold for statistical significance was set at P < 2.08E-03. RESULTS: We found a significant association between circulating levels of copper and risk of gastrointestinal infections, where a one standard deviation increase in blood levels of copper was associated with an odds ratio of gastrointestinal infections of 0.91 (95% confidence interval 0.87 to 0.97, P = 1.38E-03). This finding was robust in extensive sensitivity analyses. There was no clear association between the other micronutrients and the risk of infection. CONCLUSIONS: Our results strongly support a role of copper in the susceptibility to gastrointestinal infections.

Direct and indirect effects of socioeconomic status on sepsis risk and mortality: a mediation analysis of the HUNT Study.

BACKGROUND: Socioeconomic status (SES) may influence risk of sepsis and sepsis-related mortality, but to what extent lifestyle and health-related factors mediate this effect is not known. METHODS: The study included 65 227 participants of the population-based HUNT Study in Norway linked with hospital records to identify incident sepsis and sepsis-related deaths. Cox regression estimated HRs of sepsis risk and mortality associated with different indicators of SES, whereas mediation analyses were based on an inverse odds weighting approach. RESULTS: During ~23 years of follow-up (1.3 million person-years), 4200 sepsis cases and 1277 sepsis-related deaths occurred. Overall, participants with low SES had a consistently increased sepsis risk and sepsis-related mortality using education, occupational class and financial difficulties as indicators of SES. Smoking and alcohol consumption explained 57% of the sepsis risk related to low education, whereas adding risk factors of cardiovascular disease and chronic diseases to the model increased the explained proportion to 78% and 82%, respectively. CONCLUSION: This study shows that SES is inversely associated with sepsis risk and mortality. Approximately 80% of the effect of education on sepsis risk was explained by modifiable lifestyle and health-related factors that could be targets for prevention.

Insomnia symptoms and risk of bloodstream infections: prospective data from the prospective population-based Nord-Trøndelag Health Study (HUNT), Norway.

Previous research suggests decreased immune function and increased risk of infections in individuals with insomnia. We examined the effect of insomnia symptoms on risk of bloodstream infections (BSIs) and BSI-related mortality in a population-based prospective study. A total of 53,536 participants in the second Norwegian Nord-Trøndelag Health Study (HUNT2) (1995-97) were linked to prospective data on clinically relevant BSIs until 2011. In Cox regression, we estimated hazard ratios (HRs) with 95% confidence intervals (CIs) for a first-time BSI and for BSI-related mortality (BSI registered ≤30 days prior to death) associated with insomnia symptoms. Compared with participants who reported "no symptoms", participants reporting having "difficulty initiating sleep" (DIS) often/almost every night had a HR for a first-time BSI of 1.14 (95% CI 0.96-1.34). Participants reporting "difficulties maintaining sleep" (DMS) often/almost every night had a HR of 1.19 (95% CI 1.01-1.40), whereas those having a feeling of "non-restorative sleep" once a week or more had a HR of 1.23 (95% CI 1.04-1.46). Participants frequently experiencing all three of the above symptoms had a HR of 1.39 (1.04-1.87), whilst those who had both DIS and DMS had a HR of 1.15 (0.93-1.41) and being troubled by insomnia symptoms to a degree that affected work performance was associated with a HR of 1.41 (95% CI 1.08-1.84). The HRs for BSI-related mortality suggest an increased risk with increasing insomnia symptoms, but the CIs are wide and inconclusive. We found that frequent insomnia symptoms and insomnia symptoms that affected work performance were associated with a weak positive increased risk of BSI.

Decision support system and outcome prediction in a cohort of patients with necrotizing soft-tissue infections.

INTRODUCTION: Necrotizing Soft Tissue Infections (NSTI) are severe infections with high mortality affecting a heterogeneous patient population. There is a need for a clinical decision support system which predicts outcomes and provides treatment recommendations early in the disease course. METHODS: To identify relevant clinical needs, interviews with eight medical professionals (surgeons, intensivists, general practitioner, emergency department physician) were conducted. This resulted in 24 unique questions. Mortality was selected as first endpoint to develop a machine learning (Random Forest) based prediction model. For this purpose, data from the prospective, international INFECT cohort (N = 409) was used. RESULTS: Applying a feature selection procedure based on an unsupervised algorithm (Boruta) to the  > 1000 variables available in INFECT, including baseline, and both NSTI specific and NSTI non-specific clinical data yielded sixteen predictive parameters available on or prior to the first day on the intensive care unit (ICU). Using these sixteen variables 30-day mortality could be accurately predicted (AUC = 0.91, 95% CI 0.88-0.96). Except for age, all variables were related to sepsis (e.g. lactate, urine production, systole). No NSTI-specific variables were identified. Predictions significantly outperformed the SOFA score(p < 0.001, AUC = 0.77, 95% CI 0.69-0.84) and exceeded but did not significantly differ from the SAPS II score (p = 0.07, AUC = 0.88, 95% CI 0.83-0.92). The developed model proved to be stable with AUC  > 0.8 in case of high rates of missing data (50% missing) or when only using very early (<1 h) available variables. CONCLUSIONS: This study shows that mortality can be accurately predicted using a machine learning model. It lays the foundation for a more extensive, multi-endpoint clinical decision support system in which ultimately other outcomes and clinical questions (risk for septic shock, AKI, causative microbe) will be included.

Iron status and the risk of sepsis and severe COVID-19: a two-sample Mendelian randomization study.

Observational studies have indicated an association between iron status and risk of sepsis and COVID-19. We estimated the effect of genetically-predicted iron biomarkers on risk of sepsis and risk of being hospitalized with COVID-19, performing a two-sample Mendelian randomization study. For risk of sepsis, one standard deviation increase in genetically-predicted serum iron was associated with odds ratio (OR) of 1.14 (95% confidence interval [CI] 1.01-1.29, P = 0.031). The findings were supported in the analyses for transferrin saturation and total iron binding capacity, while the estimate for ferritin was inconclusive. We found a tendency of higher risk of hospitalization with COVID-19 for serum iron; OR 1.29 (CI 0.97-1.72, P = 0.08), whereas sex-stratified analyses showed OR 1.63 (CI 0.94-2.86, P = 0.09) for women and OR 1.21 (CI 0.92-1.62, P = 0.17) for men. Sensitivity analyses supported the main findings and did not suggest bias due to pleiotropy. Our findings suggest a causal effect of genetically-predicted higher iron status and risk of hospitalization due to sepsis and indications of an increased risk of being hospitalized with COVID-19. These findings warrant further studies to assess iron status in relation to severe infections, including the potential of improved management.

Incidence, recurring admissions and mortality of severe bacterial infections and sepsis over a 22-year period in the population-based HUNT study.

PURPOSE: Severe bacterial infections are important causes of hospitalization and loss of health worldwide. In this study we aim to characterize the total burden, recurrence and severity of bacterial infections in the general population during a 22-year period. METHODS: We investigated hospitalizations due to bacterial infection from eight different foci in the prospective population-based Trøndelag Health Study (the HUNT Study), where all inhabitants aged ≥ 20 in a Norwegian county were invited to participate. Enrollment was between 1995 and 1997, and between 2006 and 2008, and follow-up ended in February 2017. All hospitalizations, positive blood cultures, emigrations and deaths in the follow-up period were captured through registry linkage. RESULTS: A total of 79,393 (69.5% and 54.1% of the invited population) people were included, of which 42,237 (53%) were women and mean age was 48.5 years. There were 37,298 hospitalizations due to infection, affecting 15,496 (22% of all included) individuals. The median time of follow-up was 20 years (25th percentile 9.5-75th percentile 20.8). Pneumonia and urinary tract infections were the two dominating foci with incidence rates of 639 and 550 per 100,000 per year, respectively, and with increasing incidence with age. The proportion of recurring admissions ranged from 10.0% (central nervous system) to 30.0% (pneumonia), whilst the proportion with a positive blood culture ranged from 4.7% (skin- and soft tissue infection) to 40.9% (central nervous system). The 30-day mortality varied between 3.2% (skin- and soft tissue infection) and 20.8% (endocarditis). CONCLUSIONS: In this population-based cohort, we observed a great variation in the incidence, positive blood culture rate, recurrence and mortality between common infectious diseases. These results may help guide policy to reduce the infectious disease burden in the population.

Explaining sex differences in risk of bloodstream infections using mediation analysis in the population-based HUNT study in Norway.

Previous studies indicate sex differences in incidence and severity of bloodstream infections (BSI). We examined the effect of sex on risk of BSI, BSI mortality, and BSI caused by the most common infecting bacteria. Using causal mediation analyses, we assessed if this effect is mediated by health behaviours (smoking, alcohol consumption), education, cardiovascular risk factors (systolic blood pressure, non-HDL cholesterol, body mass index) and selected comorbidities. This prospective study included 64,040 participants (46.8% men) in the population-based HUNT2 Survey (1995-1997) linked with hospital records in incident BSI. During median follow-up of 15.2 years, 1840 (2.9%) participants (51.3% men) experienced a BSI and 396 (0.6%) died (56.6% men). Men had 41% higher risk of first-time BSI (95% confidence interval (CI), 28-54%) than women. Together, health behaviours, education, cardiovascular risk factors and comorbidities mediated 34% of the excess risk of BSI observed in men. The HR of BSI mortality was 1.87 (95% CI 1.53-2.28), for BSI due to S. aureus 2.09 (1.28-2.54), S. pneumoniae 1.36 (1.05-1.76), E. coli 0.97 (0.84-1.13) in men vs women. This study shows that men have higher risk of BSI and BSI mortality than women. One-third of this effect was mediated by potential modifiable risk factors for incident BSI.

Risk of lower respiratory tract infections: a genome-wide association study with Mendelian randomization analysis in three independent European populations.

OBJECTIVE: Lower respiratory tract infections (LRTIs) are a leading cause of morbidity and mortality worldwide. Few studies have previously investigated genetic susceptibility and potential risk factors for LRTI. METHODS: We used data from the UK Biobank, Trøndelag Health Study (HUNT), and FinnGen to conduct a genome-wide association study (GWAS). Cases were subjects hospitalized with LRTI, and controls were subjects with no such hospitalization. We conducted stratification and interaction analyses to evaluate whether the genetic effect of LRTI differed by sex or smoking. Mendelian randomization (MR) analyses were conducted to identify the unconfounded relationship between cardiometabolic risk factors and LRTI. RESULTS: A total of 25 320 cases and 575 294 controls were included. The 15q25.1 locus reached genome-wide significance in the meta-analysis (rs10519203: OR 0.94, p 3.87e-11). The protective effect of effect allele of rs10519203 was present among smokers (OR 0.90, 95%CI 0.87-0.92, p 1.38e-15) but not among never-smokers (OR 1.01, 95%CI 0.97-1.06, p 5.20e-01). In MR analyses, we found that increasing body mass index (OR 1.31, 95%CI 1.24-1.40, p 3.78e-18), lifetime smoking (OR 2.83, 95%CI 2.34-3.42, p 6.56e-27), and systolic blood pressure robustly increased the risk of LRTIs (OR 1.11, 95%CI 1.02-1.22, p 1.48e-02). CONCLUSION: A region in 15q25.1 was strongly associated with LRTI susceptibility. Reduction in the prevalence of smoking, overweight, obesity, and hypertension may reduce the disease burden of LRTIs.

Thyroid function and risk of bloodstream infections: Results from the Norwegian prospective population-based HUNT Study.

OBJECTIVE: Previous studies on thyroid function and risk of infection is conflicting and often stem from intensive care cohorts were nonthyroidal illness syndrome (NTIS) may be present. The objective of this study was to identify the risk of bloodstream infections (BSI) and BSI-related mortality with thyroid-stimulating hormone (TSH) levels within the reference range in a general population. DESIGN: Prospective follow-up. PARTICIPANTS: The HUNT2 (1995-97) included 34,619 participants with information on TSH levels. MEASUREMENTS: Hazard ratios (HRs) with 95% confidence interval (CI) confirmed BSIs and BSI-related mortality until 2011. RESULTS: During a median follow-up of 14.5 years, 1179 experienced at least one episode of BSI and 208 died within 30 days after a BSI. TSH levels within the reference range of 0.5-4.5 mU/L were not associated with the risk of first-time BSI, with an HR of 0.97 (95% CI: 0.90-1.04) per mU/L. Stratified by baseline age < or ≥65 years, TSH was inversely associated with the risk of BSI (HR: 0.88; 95% CI: 0.78-1.00 per mU/L) in the youngest age group only. Persons with any baseline thyroid disease had a 30% risk and the hyperthyroid subgroup a 57%, and hypothyroidism a 20% increased risk of BSI. TSH levels were not clearly associated with BSI mortality, but the HRs were imprecise due to few BSI-related deaths. CONCLUSION: There was some evidence of a weak inverse association between TSH levels and the risk of BSI in persons below 65 years of age. The increased risk seen in persons with thyroid illness is probably explained by confounding by concurrent ill health.

Correction: Early diagnosis of sepsis in emergency departments, time to treatment, and association with mortality: An observational study.

[This corrects the article DOI: 10.1371/journal.pone.0227652.].

The Role of FER rs4957796 in the Risk of Developing and Dying from a Bloodstream Infection: A 23-Year Follow-up of the Population-based Nord-Trøndelag Health Study.

BACKGROUND: Bloodstream infection and sepsis are major causes of health loss worldwide, and it is important to identify patients at risk of developing and dying from these conditions. The single-nucleotide polymorphism most strongly associated with sepsis mortality is FER rs4957796. However, it is not known how this variant is associated with bloodstream infection incidence and mortality. METHODS: We used prospective data from 1995-2017 from the population-based HUNT Study. Genotypes were ascertained from blood samples, and additional genotypes were imputed. Information on bloodstream infection and diagnosis codes at hospitalization were collected through record linkage with all hospitals in the area. RESULTS: A total of 69 294 patients were included. Patients with the rs4957796 CC genotype had an increased risk of developing a bloodstream infection compared with the TT genotype (hazard ratio [HR], 1.20; 95% confidence interval [CI], 1.00-1.43). However, there was a protective additive effect of the C allele in terms of mortality in the total study population (HR, 0.77; 95% CI, .64-.92 per copy of the C allele) and among bloodstream infection patients (odds ratio, 0.70; 95% CI, .58-.85 per copy of the C allele). The results did not appear to be affected by selection bias. CONCLUSIONS: The rs4957796 CC genotype was associated with an increased risk of contracting a bloodstream infection but with a reduced risk of dying from one. The latter finding is in line with studies of sepsis case fatality, while the former expands our understanding of the immunoregulatory role of this polymorphism.

The promise and pitfalls of composite endpoints in sepsis and COVID-19 clinical trials.

Composite endpoints reveal the tendency for statistical convention to arise locally within subfields. Composites are familiar in cardiovascular trials, yet almost unknown in sepsis. However, the VITAMINS trial in patients with septic shock adopted a composite of mortality and vasopressor-free days, and an ordinal scale describing patient status rapidly became standard in COVID studies. Aware that recent use could incite interest in such endpoints, we are motivated to flag their potential value and pitfalls for sepsis research and COVID studies.