Life satisfaction components and all-cause and cause-specific mortality: A large prospective cohort study.

BACKGROUND: Which life satisfaction components could be a target of positive psychological interventions for longevity is largely unknown. We aimed to investigate association of the composite measure of life satisfaction and its individual components with mortality. METHODS: This cohort study included UK Biobank participants who responded to questions concerning five components of life satisfaction at baseline. We generated a composite score representing overall life satisfaction, ranging from 0 (lowest) to 5 (highest). The outcomes were all-cause and cause-specific mortality. We used multivariable Cox regression to estimate hazard ratios (HR) for the associations of interest. RESULTS: Among 165,842 eligible participants, 12,261 all-cause deaths were observed over a median of 12.9-year follow-up. Overall life satisfaction was inversely associated with all-cause mortality (adjusted HR 0.94 [95% CI: 0.93-0.95] per 1 score increment). Health satisfaction showed the strongest association with all-cause mortality, with a fully adjusted HR of 0.52 (95% CI: 0.49-0.55) for high/extreme satisfaction and 0.63 (95% CI: 0.59-0.66) for moderate satisfaction, compared with unsatisfaction (P-trend<0.001), independent of other satisfaction components, regardless of physical health and sociodemographics. The association for family, friendship, work and financial satisfaction was attenuated when adjusted for other life satisfaction components. Similar findings were observed for cause-specific mortality. LIMITATIONS: Observational study with single baseline measurement of life satisfaction precludes the ability to establish causal relationship. CONCLUSIONS: Higher overall life satisfaction was associated with lower mortality. As the major contributor to lower mortality regardless of physical health and sociodemographics, health satisfaction could be an important target of positive psychological interventions for longevity.

Efficacy of SARS-CoV-2 vaccines and the dose-response relationship with three major antibodies: a systematic review and meta-analysis of randomised controlled trials.

BACKGROUND: The efficacy of SARS-CoV-2 vaccines in preventing severe COVID-19 illness and death is uncertain due to the rarity of data in individual trials. How well the antibody concentrations can predict the efficacy is also uncertain. We aimed to assess the efficacy of these vaccines in preventing SARS-CoV-2 infections of different severities and the dose-response relationship between the antibody concentrations and efficacy. METHODS: We did a systematic review and meta-analysis of randomised controlled trials (RCTs). We searched PubMed, Embase, Scopus, Web of Science, Cochrane Library, WHO, bioRxiv, and medRxiv for papers published between Jan 1, 2020 and Sep 12, 2022. RCTs on the efficacy of SARS-CoV-2 vaccines were eligible. Risk of bias was assessed using the Cochrane tool. A frequentist, random-effects model was used to combine efficacy for common outcomes (ie, symptomatic and asymptomatic infections) and a Bayesian random-effects model was used for rare outcomes (ie, hospital admission, severe infection, and death). Potential sources of heterogeneity were investigated. The dose-response relationships of neutralising, spike-specific IgG and receptor binding domain-specific IgG antibody titres with efficacy in preventing SARS-CoV-2 symptomatic and severe infections were examined by meta-regression. This systematic review is registered with PROSPERO, CRD42021287238. FINDINGS: 28 RCTs (n=286 915 in vaccination groups and n=233 236 in placebo groups; median follow-up 1-6 months after last vaccination) across 32 publications were included in this review. The combined efficacy of full vaccination was 44·5% (95% CI 27·8-57·4) for preventing asymptomatic infections, 76·5% (69·8-81·7) for preventing symptomatic infections, 95·4% (95% credible interval 88·0-98·7) for preventing hospitalisation, 90·8% (85·5-95·1) for preventing severe infection, and 85·8% (68·7-94·6) for preventing death. There was heterogeneity in the efficacy of SARS-CoV-2 vaccines against asymptomatic and symptomatic infections but insufficient evidence to suggest whether the efficacy could differ according to the type of vaccine, age of the vaccinated individual, and between-dose interval (p>0·05 for all). Vaccine efficacy against symptomatic infection waned over time after full vaccination, with an average decrease of 13·6% (95% CI 5·5-22·3; p=0·0007) per month but can be enhanced by a booster. We found a significant non-linear relationship between each type of antibody and efficacy against symptomatic and severe infections (p<0·0001 for all), but there remained considerable heterogeneity in the efficacy, which cannot be explained by antibody concentrations. The risk of bias was low in most studies. INTERPRETATION: The efficacy of SARS-CoV-2 vaccines is higher for preventing severe infection and death than for preventing milder infection. Vaccine efficacy wanes over time but can be enhanced by a booster. Higher antibody titres are associated with higher estimates of efficacy but precise predictions are difficult due to large unexplained heterogeneity. These findings provide an important knowledge base for interpretation and application of future studies on these issues. FUNDING: Shenzhen Science and Technology Programs.

Regular Glucosamine Use May Have Different Roles in the Risk of Site-Specific Cancers: Findings from a Large Prospective Cohort.

BACKGROUND: Previous studies indicated that glucosamine supplements may have a general anticancer effect. This study aimed to assess whether the potential effect differs across different types of cancers in a large prospective cohort study. METHODS: All participants from the UK Biobank who were free of cancers and had complete information on glucosamine use at baseline were included and followed up from 2006 until 2021. Cox proportional hazards models were used to assess the associations between regular glucosamine use and different site-specific cancers. Subgroup analyses were performed to explore potential interactions. Several sensitivity analyses were conducted to assess the robustness of the main findings. RESULTS: A total of 450,207 eligible participants (mean age: 56.2 years; females: 53.3%) were included, of whom 84,895 (18.9%) reported regular glucosamine use at baseline. During a median of 12.5 years follow-up, glucosamine use was significantly associated with an increased risk of overall cancer [HR, 1.04; 95% confidence interval (CI), 1.01-1.06], skin cancer (HR, 1.11; 95% CI, 1.07-1.15), and prostate cancer (HR, 1.07; 95% CI, 1.01-1.13), and with a reduced risk of lung cancer (HR, 0.88; 95% CI, 0.79-0.97) after adjusting for potential confounders. Statistical interaction was observed for gender, age, and education for the association of glucosamine use with overall cancer risk (all Pinteraction < 0.027). These results remained unchanged in the sensitivity analyses. CONCLUSIONS: Regular glucosamine use was associated with lower risk of lung cancer but higher risk of skin cancer, prostate cancer, and overall cancer. IMPACT: The roles of glucosamine use potentially differ in the development of different site-specific cancers.