Combined healthy lifestyle behaviours and incident dementia: A systematic review and dose-response meta-analysis of cohort studies.

BACKGROUND: The associations of combined healthy lifestyle behaviours and incident dementia have not been systematically reviewed and the dose-response relationship was uncertain. OBJECTIVES: To evaluate the associations of combined healthy lifestyle behaviours with incident dementia and other cognitive outcomes, assess the dose-response relationship between the number of lifestyle behaviours and incident dementia, and summarise the adherence to healthy lifestyle behaviours. DESIGN: Systematic review and meta-analysis. METHODS: PubMed, EMBASE, Web of Science and PsycINFO were searched from inception to 20 Jan 2024. Cohort studies reporting associations of combined healthy lifestyle behaviours with incident dementia or other cognitive outcomes were included. We used the random-effects meta-analysis to pool the risk estimates and the robust error meta-regression method to examine the dose-response relationship. The methodological quality was assessed using the Newcastle-Ottawa Scale. RESULTS: A total of 22 articles including 25 cohort studies mostly from high-income economics were included, with all assessed as high methodological quality. Adherence to a healthy lifestyle was associated with a decreased risk of incident dementia, either per healthy lifestyle behaviour increase (pooled hazard ratio 0.89, 95 % confidence interval 0.85-0.94) or the highest level versus the lowest level (pooled hazard ratio 0.61, 95 % confidence interval 0.49-0.76). An inverse, linear dose-response relationship (Pnon-linear = 0.845) between the number of healthy lifestyle behaviours and incident dementia was observed, with an 11 % risk reduction for each healthy behaviour increase. A relatively limited number of included studies indicated that adherence to a healthy lifestyle combination could yield benefits for cognitive decline, global cognition, memory and executive function. In addition, the adherence rates typically decreased as the number of healthy lifestyle behaviours increased. CONCLUSIONS: Adherence to a healthy lifestyle was associated with a lower risk of incident dementia and other cognitive outcomes. It is important to find a subtle balance between the benefits and adherence. Further large cohort studies for combined lifestyle behaviours with specific cognitive outcomes and dose-response relationships are required, especially based on middle- and low-income populations. REGISTRATION: The study was registered in PROSPERO (CRD42023418509). TWEETABLE ABSTRACT: Engaging in a greater number of healthy lifestyle behaviours yields increased benefits in preventing dementia, albeit with lower adherence rates as a trade-off. Finding a delicate balance between the benefits and adherence is crucial.

Methodological quality of systematic reviews on atopic dermatitis treatments: a cross-sectional study.

BACKGROUND: Systematic reviews (SRs) could offer the best evidence supporting interventions, but methodological flaws limit their trustworthiness in decision-making. This cross-sectional study appraised the methodological quality of SRs on atopic dermatitis (AD) treatments. METHODS: We searched MEDLINE, EMBASE, PsycINFO, and Cochrane Database for SRs on AD treatments published in 2019-2022. We extracted SRs' bibliographical data and appraised SRs' methodological quality with AMSTAR (A MeaSurement Tool to Assess systematic Reviews) 2. We explored associations between methodological quality and bibliographical characteristics. RESULTS: Among the 52 appraised SRs, only one (1.9%) had high methodological quality, while 45 (86.5%) critically low. For critical domains, only five (9.6%) employed comprehensive search strategy, seven (13.5%) provided list of excluded studies, 17 (32.7%) considered risk of bias in primary studies, 21 (40.4%) contained registered protocol, and 24 (46.2%) investigated publication bias. Cochrane reviews, SR updates, SRs with European corresponding authors, and SRs funded by European institutions had better overall quality. Impact factor and author number positively associated with overall quality. CONCLUSIONS: Methodological quality of SRs on AD treatments is unsatisfactory. Future reviewers should improve the above critical methodological aspects. Resources should be devolved into upscaling evidence synthesis infrastructure and improving critical appraisal skills of evidence users.

Association of healthy lifestyle behaviours with incident irritable bowel syndrome: a large population-based prospective cohort study.

OBJECTIVES: To evaluate the association between healthy lifestyle behaviours and the incidence of irritable bowel syndrome (IBS). DESIGN: Population-based prospective cohort study. SETTING: The UK Biobank. PARTICIPANTS: 64 268 adults aged 37 to 73 years who had no IBS diagnosis at baseline were enrolled between 2006 and 2010 and followed up to 2022. MAIN EXPOSURE: The five healthy lifestyle behaviours studied were never smoking, optimal sleep, high level of vigorous physical activity, high dietary quality and moderate alcohol intake. MAIN OUTCOME MEASURE: The incidence of IBS. RESULTS: During a mean follow-up of 12.6 years, 961 (1.5%) incident IBS cases were recorded. Among the 64 268 participants (mean age 55.9 years, 35 342 (55.0%) female, 7604 (11.8%) reported none of the five healthy lifestyle behaviours, 20 662 (32.1%) reported 1 behaviour, 21 901 (34.1%) reported 2 behaviours and 14 101 (21.9%) reported 3 to 5 behaviours at baseline. The multivariable adjusted hazard ratios associated with having 1, 2 and 3 to 5 behaviours for IBS incidence were 0.79 (95% confidence intervals 0.65 to 0.96), 0.64 (0.53 to 0.78) and 0.58 (0.46 to 0.72), respectively (P for trend <0.001). Never smoking (0.86, 0.76 to 0.98, P=0.02), high level of vigorous physical activity (0.83, 0.73 to 0.95, P=0.006) and optimal sleep (0.73, 0.60 to 0.88, P=0.001) demonstrated significant independent inverse associations with IBS incidence. No significant interactions were observed between these associations and age, sex, employment status, geographic location, gastrointestinal infection, endometriosis, family history of IBS or lifestyle behaviours. CONCLUSIONS: Adhering to a higher number of healthy lifestyle behaviours is significantly associated with a lower incidence of IBS in the general population. Our findings suggest the potential of lifestyle modifications as a primary prevention strategy for IBS.