Associations of metabolic syndrome with cognitive function and dementia risk: Evidence from the UK Biobank cohort.

AIM: To investigate the associations of metabolic syndrome (MetS) with cognitive function, dementia and its subtypes. METHODS: Based on the participants recruited by UK Biobank, this study aims to investigate the associations of MetS with cognitive function, dementia and its subtypes. Generalized estimating equations, Cox proportional risk models, and multiple linear regression models were respectively used to assess associations between MetS and dementia-related outcomes. RESULTS: Among the 363,231 participants, 95,713 had MetS at baseline. The results showed that MetS was significantly associated with cognitive function related to fluid intelligence and prospective memory at follow-up. Among participants aged ≥60 years, MetS was correlated with elevated risk of all-cause dementia, particularly vascular dementia (VaD) [hazard ratio 1.115 (95% confidence interval: 1.047, 1.187), hazard ratio 1.393 (95% confidence interval: 1.233, 1.575), respectively]. With increasing MetS components, the risk of all-cause dementia and VaD tended to be elevated. MetS has also been associated with dementia-related structural changes in the brain, including alterations in overall brain volume, white matter volume, grey matter volume and white matter integrity. CONCLUSION: MetS was associated with poorer cognitive performance and might increase the risk of all-cause dementia as well as VaD, but the effect on Alzheimer's disease was not significant. Holistic control of the MetS may benefit the prevention and control of cognitive impairment and dementia.

Associations between metabolic syndrome and anxiety, and the mediating role of inflammation: Findings from the UK Biobank.

OBJECTIVES: To investigate the association between metabolic syndrome (MetS) and anxiety and to explore the mediating role of inflammation indicators in this relationship based on the UK Biobank prospective cohort. METHODS: This population-based retrospective cohort study analyzed data from 308,352 participants. MetS was defined according to criteria jointly developed by the American Heart Association, the National Heart, Lung, and Blood Institute, and the International Diabetes Federation. Anxiety was defined using ICD-10 codes. Cox proportional risk regression models were used to explore the hazard ratios (HRs) between MetS, components of MetS, number of MetS components, and anxiety. The mediating effect of inflammation on the association between MetS and anxiety was explored using longitudinal mediation analysis. RESULTS: A total of 308,352 participants were included in this study. Of these, 9471 (3.071 %) developed anxiety over a mean follow-up of 12.05 years. In the fully adjusted model, MetS increased the risk of anxiety by 13.6 % (HR: 1.136, 95 %CI: 1.085-1.189). All MetS components significantly increased the risk of anxiety, with HRs ranging from 1.066 to 1.165. When MetS was treated as a linear variable, the risk of anxiety increased by 6.5 % per component increment. Age-stratified results showed that the risk of MetS for anxiety was higher among those <55 years (HR: 1.23, 95 %CI: 1.13-1.33) than among those ≥55 years (HR: 1.12, 95 %CI: 1.06-1.18). The mediating effects of platelets, lymphocytes, neutrophils, C-reactive protein, leukocytes, and INFLA scores on the association between MetS and anxiety were significant, with mediating effects of 2.30 %, 7.20 %, 15.9 %, 20.7 %, 22.0 %, and 25.3 %, respectively, and a combined mediating effect of these inflammatory factors was 30.8 % (except for INFLA scores). CONCLUSIONS: MetS and its components significantly increased the risk of anxiety, which increased with the number of components. This association may be partially mediated by serum inflammatory indicators, suggesting that MetS may increase the risk of anxiety by elevating the level of chronic inflammation.

Association between prenatal exposure to per- and polyfluoroalkyl substances and neurodevelopment in children: Evidence based on birth cohort.

BACKGROUND: Although numerous studies have examined the effect of prenatal per- and polyfluoroalkyl substances (PFAS) exposure on neurodevelopment in children, findings have been inconsistent. OBJECTIVE: To better understand the effects of PFAS exposure during pregnancy on offspring neurodevelopment, we conducted a systematic review of prenatal exposure to different types of PFAS and neurodevelopment in children. METHODS: A comprehensive search was conducted in the PubMed, Web of Science, and EMBASE electronic databases up to March 2023. Only birth cohort studies that report a specific association between PFAS exposure during pregnancy and neurodevelopment were included in this review. RESULTS: 31 birth cohort studies that met the inclusion criteria were qualitatively integrated. Among these, 14 studies investigated the impact of PFAS exposure during pregnancy on cognition, 13 on neurobehavior, and 4 on both cognition and neurobehavior. Additionally, 4 studies explored the influence of PFAS on children's comprehensive development. CONCLUSION: Prenatal PFAS exposure was associated with poor neurodevelopment in children, including psychomotor development, externalizing behavior, and comprehensive development. However, conclusive evidence regarding its effects on other neurological outcomes remains limited. In addition, sex-specific effects on social behavior and sleep problems were identified.

Oxidative balance scores and depressive symptoms: Mediating effects of oxidative stress and inflammatory factors.

BACKGROUND: Few studies have examined the combined effects of dietary and lifestyle factors on depressive symptoms. This study aimed to evaluate the association between oxidative balance score (OBS) and depressive symptoms and the underlying mechanisms. METHODS: A total of 21,283 adults from the 2007 to 2018 National Health and Nutrition Examination Survey (NHANES) were included. Depressive symptoms were defined as a total score of ≥10 on the Patient's Health Questionnaire (PHQ-9). Twenty dietary and lifestyle factors were selected to calculate the OBS. Multivariable logistic regression analyses were used to evaluate the association between OBS and depression risk. Mediation analyses were conducted to explore the roles of oxidative stress and inflammatory markers. RESULTS: In multivariate model, a significant negative association was found between OBS and depression risk. Compared with those in OBS tertile 1, participants in tertile 3 had lower odds of developing depressive symptoms (OR:0.50; 95 % CI:0.40-0.62; P < 0.001). Restricted cubic splines showed a linear relationship between OBS and depression risk (P for nonlinearity = 0.67). Moreover, higher OBS was found to be associated with lower depression scores (ß = -0.07; 95 % CI:-0.08, -0.05; P < 0.001). GGT concentrations and WBC counts mediated the association between OBS and depression scores by 5.72 % and 5.42 %, respectively (both P < 0.001), with a joint mediated effect of 10.77 % (P < 0.001). LIMITATIONS: This study was a cross-sectional design making it difficult to infer a causal association. CONCLUSIONS: OBS is negatively associated with depression, which may be mediated in part by oxidative stress and inflammation.