Influence of Diabetes Duration and Glycemic Control on Dementia: A Cohort Study

Prevalence of cognitive impairment and associated factors in older people

BACKGROUND

Older people are the fastest-growing age group, with the highest risk of cognitive impairment. This study assessed the prevalence and associated factors with cognitive impairment in community-dwelling older people.

METHODS

Older people were interviewed and accomplished through sociodemographic and health questionnaires. The quantitative variables were described by mean and standard deviation or median and interquartile range. The significance level adopted was 5 % (p < 0.05). The association between the quantitative variables was evaluated using the Pearson or Spearman correlation coefficients.

RESULTS

The research population comprised 165 long-lived adults aged ≥80. The youngest one was 80, and the oldest one was 94 years old. The participants were 84.8 ± 3.6 years old, female (63 %) with a mean of education of 2.9 ± 1.8 years. A poor performance in the Mini-Mental State Examination (MMSE) was found in 58 (35.2 %) individuals when adjusted for educational level. After adjustment for confounding factors, body mass index (BMI) (p = 0.09), total older adults' income (up to 1 minimum wage [mw], p = 0.023; over 1 to 2 mw, p = 0.023), functional disability (Moderate dependence 75 %, p = 0.038; Moderate dependence 50 %, p = 0.081; Moderate dependence 25 %, p = 0.054), and the anxiety scale (p = 0.032), remained associated with cognitive impairment.

CONCLUSIONS

This study showed that BMI, total older adults' income, functional disability, and anxiety are related to cognitive impairment in long-lived adults. This study has some limitations, such as the fact that it is a cross-sectional study, the reduced number of individuals, and the fact that there were no comparisons among different ages and populations.

Microvascular burden and long-term risk of stroke and dementia in type 2 diabetes mellitus

OBJECTIVE

To examine the associations between microvascular disease (MVD) and risk of stroke, dementia, and their major subtypes among individuals with type 2 diabetes mellitus (T2DM).

METHODS

We included 26,173 participants with T2DM from the UK Biobank who had no known stroke or dementia at baseline. MVD burden was reflected by the presence of retinopathy, peripheral neuropathy, and chronic kidney disease. Cox regression models were used to estimate hazard ratios (HRs) and 95 % confidential intervals (CIs) of stroke and dementia associated with overall MVD burden and individual MVD.

RESULTS

During a median follow-up of 11.5 years, 1103 incident stroke (964 ischemic and 269 hemorrhagic stroke) and 813 incident dementia (312 Alzheimer's disease and 304 vascular dementia) cases were identified. The risk of stroke, dementia, and their major subtypes all increased with an increasing number of MVD (all P-trend <0.001). The adjusted HRs (95 % CIs) comparing three with no MVD were 5.03 (3.16, 8.02) for all stroke, 4.57 (2.75, 7.59) for ischemic stroke, and 6.60 (2.65, 16.43) for hemorrhagic stroke. The corresponding estimates were 4.28 (2.33, 7.86) for all-cause dementia, 6.96 (3.02, 16.01) for Alzheimer's disease, and 3.81 (1.40, 10.42) for vascular dementia. Among the three MVD, chronic kidney disease showed the strongest associations with both stroke subtypes, while peripheral neuropathy was most strongly associated with both dementia subtypes.

CONCLUSIONS

Risk of stroke, dementia, and their major subtypes increased with an increasing number of MVD. The associations of individual MVD with stroke and dementia varied substantially by types of MVD.

Biomarkers of Neurodegeneration and Alzheimer's Disease Neuropathology in Adolescents and Young Adults with Youth-Onset Type 1 or Type 2 Diabetes: A Proof-of-Concept Study

Adult-onset diabetes increases one's risk of neurodegenerative disease including Alzheimer's disease (AD); however, the risk associated with youth-onset diabetes (Y-DM) remains underexplored. We quantified plasma biomarkers of neurodegeneration and AD in participants with Y-DM from the SEARCH cohort at adolescence and young adulthood (Type 1, n = 25; Type 2, n = 25; 59% female; adolescence, age = 15 y/o [2.6]; adulthood, age = 27.4 y/o [2.2]), comparing them with controls (adolescence, n = 25, age = 14.8 y/o [2.7]; adulthood, n = 21, age = 24.9 y/o [2.8]). Plasma biomarkers, including glial fibrillary acidic protein (GFAP), neurofilament light chain protein (NfL), phosphorylated tau-181 (pTau181), and amyloid beta (Aβ40, Aβ42), were measured via Simoa. A subset of participants (n = 7; age = 27.5 y/o [5.7]) and six controls (age = 25.1 y/o [4.5]) underwent PET scans to quantify brain amyloid and tau densities in AD sensitive brain regions. Y-DM adolescents exhibited lower plasma levels of Aβ40, Aβ42, and GFAP, and higher pTau181 compared to controls (p < 0.05), a pattern persisting into adulthood (p < 0.001). All biomarkers showed significant increases from adolescence to adulthood in Y-DM (p < 0.01), though no significant differences in brain amyloid or tau were noted between Y-DM and controls in adulthood. Preliminary evidence suggests that preclinical AD neuropathology is present in young people with Y-DM, indicating a potential increased risk of neurodegenerative diseases.

The relationship between diabetes and the dementia risk: a meta-analysis

BACKGROUND

The link between diabetes and dementia risk is not well understood. This study evaluates the factors linking diabetes to dementia onset, providing guidance for preventing dementia in diabetic patients.

METHODS

This analysis utilized databases such as PubMed, Embase, Web of Science, and the Cochrane Library to review literature from January 31, 2012, to March 5, 2023. Articles were rigorously assessed using specific inclusion and exclusion criteria. The Newcastle-Ottawa Scale (NOS) was used to evaluate the quality of the studies. Data analysis was performed with STATA 15.0.

RESULTS

The study analyzed 15 articles, covering 10,103,868 patients, with 8,821,516 diagnosed with diabetes. The meta-analysis reveals a substantial association between diabetes and an increased risk of dementia [RR: 1.59, 95%CI (1.40-1.80), P < 0.01, I²=96.4%]. A diabetes duration of less than five years is linked to a higher dementia risk [RR: 1.29, 95%CI (1.20-1.39), P < 0.01, I²=92.6%]. Additionally, hypoglycemia significantly raises dementia risk [RR: 1.56, 95%CI (1.13-2.16), P < 0.01, I²=51.5%]. Analyses of blood sugar control, glycated hemoglobin, and fasting blood sugar indicated no significant effects on the onset of dementia.

CONCLUSION

Diabetes notably increases dementia risk, particularly where diabetes duration is under five years or hypoglycemia is present.

REGISTRATION

The research protocol was registered with PROSPERO and assigned the registration number CRD42023394942.

Association of vitamin D and cognition in people with type 2 diabetes: a systematic review

CONTEXT

There is a high prevalence of vitamin D deficiency and impaired cognitive function in people with type 2 diabetes mellitus (T2DM).

OBJECTIVE

To critically and systematically review the literature on the association between vitamin D status and cognitive performance in people with type 2 diabetes.

DATA SOURCES

This review was conducted according to PRISMA recommendations. MEDLINE, SCOPUS, the Cochrane Library, and Web of Science databases were searched using the terms "Diabetes Mellitus, Type 2", "Cognitive Function", and "Vitamin D".

DATA EXTRACTION

Eight observational and 1 randomized study were included, containing data of 14 648 adult and elderly individuals (19-74 y). All extracted data were compiled, compared, and critically analyzed.

DATA ANALYSIS

There is no strong evidence that lower serum concentrations of vitamin D and vitamin D-binding protein are associated with worsening cognitive function in individuals with T2DM. Vitamin D supplementation (12 wk) improved the scores of some executive functioning tests, although there was no difference between low doses (5000 IU/wk) and high doses (50 000 IU/wk).

CONCLUSIONS

There is no high-quality evidence demonstrating an association between vitamin D status and cognitive function, or clinical benefits on cognition from vitamin D supplementation in individuals with T2DM. Future studies are needed. Systematic Review Registration: PROSPERO registration no. CRD42021261520.

Relationship of microvascular complications and healthy lifestyle with all-cause and cardiovascular mortality in women compared with men with type 2 diabetes

BACKGROUND

Sex differences exist in the prevalence of microvascular disease (MVD) and healthy-lifestyle adherence. Whether MVD and healthy lifestyles are associated with mortality risk similarly for women and men who have type 2 diabetes mellitus (T2DM) remains unknown.

METHODS

The present study included 9992 women and 15,860 men with T2DM from the UK Biobank. MVDs included retinopathy, peripheral neuropathy, and chronic kidney disease. Healthy lifestyle factors consisted of ideal BMI, nonsmoking, healthy diet, regular exercise, and appropriate sleep duration. Sex-specific hazard ratios (HRs) of mortality associated with the MVDs or healthy lifestyles were calculated and women-to-men ratio of HRs (RHR) were further estimated, after multivariable adjustment for potential confounders.

RESULTS

During a median of 12.7 years of follow-up, 4346 (1202 in women) all-cause and 1207 (254 in women) CVD deaths were recorded. The adjusted HRs (95% CI) of all-cause mortality for 1 additional increment of the MVDs were 1.71 (1.55, 1.88) for women and 1.48 (1.39, 1.57) for men, with an RHR of 1.16 (1.03, 1.30). The corresponding RHR was 1.36 (1.09, 1.69) for cardiovascular mortality. Adhering to a healthy lifestyle (≥4 vs. ≤1 lifestyle factor) was associated with an approximately 60%-70% lower risk of all-cause and cardiovascular mortality without sex differences (P-interaction >0.70). Furthermore, as compared with having no MVD and an unfavorable lifestyle, having ≥2 MVDs but a favorable lifestyle was not associated with a higher risk of all-cause mortality either in women (HR = 0.88; 95% CI: 0.49, 1.60) or in men (HR = 0.95; 95% CI: 0.64, 1.40), similarly when considering cardiovascular mortality.

CONCLUSIONS

In T2DM, while MVDs are more strongly associated with mortality risk in women than in men, adhering to a favorable lifestyle is associated with a substantially lower risk of mortality and may eliminate the detrimental impact of MVDs in both sexes.

Association of Postoperative Delirium With Incident Dementia and Graft Outcomes Among Kidney Transplant Recipients

BACKGROUND

Kidney transplant (KT) recipients have numerous risk factors for delirium, including those shared with the general surgical population (eg, age and major surgery) and transplant-specific factors (eg, neurotoxic immunosuppression medications). Evidence has linked delirium to long-term dementia risk in older adults undergoing major surgery. We sought to characterize dementia risk associated with post-KT delirium.

METHODS

Using the United States Renal Data System datasets, we identified 35 800 adult first-time KT recipients ≥55 y. We evaluated risk factors for delirium using logistic regression. We evaluated the association between delirium and incident dementia (overall and by subtype: Alzheimer's, vascular, and other/mixed-type), graft loss, and death using Fine and Gray's subhazards models and Cox regression.

RESULTS

During the KT hospitalization, 0.9% of recipients were diagnosed with delirium. Delirium risk factors included age (OR = 1.40, 95% CI, 1.28-1.52) and diabetes (OR = 1.38, 95% CI, 1.10-1.73). Delirium was associated with higher risk of death-censored graft loss (aHR = 1.52, 95% CI, 1.12-2.05) and all-cause mortality (aHR = 1.53, 95% CI, 1.25-1.89) at 5 y post-KT. Delirium was also associated with higher risk of dementia (adjusted subhazard ratio [aSHR] = 4.59, 95% CI, 3.48-6.06), particularly vascular dementia (aSHR = 2.51, 95% CI, 1.01-6.25) and other/mixed-type dementia (aSHR = 5.58, 95% CI, 4.24-7.62) subtypes. The risk of all-type dementia associated with delirium was higher for younger recipients aged between 55 and 64 y ( Pinteraction  = 0.01).

CONCLUSIONS

Delirium is a strong risk factor for subsequent diagnosis of dementia among KT recipients, particularly those aged between 55 and 64 y at the time of transplant. Patients experiencing posttransplant delirium might benefit from early interventions to enhance cognitive health and surveillance for cognitive impairment to enable early referral for dementia care.

Improving Cognitive Function with Nutritional Supplements in Aging: A Comprehensive Narrative Review of Clinical Studies Investigating the Effects of Vitamins, Minerals, Antioxidants, and Other Dietary Supplements

Cognitive impairment and dementia are burgeoning public health concerns, especially given the increasing longevity of the global population. These conditions not only affect the quality of life of individuals and their families, but also pose significant economic burdens on healthcare systems. In this context, our comprehensive narrative review critically examines the role of nutritional supplements in mitigating cognitive decline. Amidst growing interest in non-pharmacological interventions for cognitive enhancement, this review delves into the efficacy of vitamins, minerals, antioxidants, and other dietary supplements. Through a systematic evaluation of randomized controlled trials, observational studies, and meta-analysis, this review focuses on outcomes such as memory enhancement, attention improvement, executive function support, and neuroprotection. The findings suggest a complex interplay between nutritional supplementation and cognitive health, with some supplements showing promising results and others displaying limited or context-dependent effectiveness. The review highlights the importance of dosage, bioavailability, and individual differences in response to supplementation. Additionally, it addresses safety concerns and potential interactions with conventional treatments. By providing a clear overview of current scientific knowledge, this review aims to guide healthcare professionals and researchers in making informed decisions about the use of nutritional supplements for cognitive health.

The Association Between Exposure to Air Pollution and Dementia Incidence: The Modifying Effect of Smoking

BACKGROUND

The influence of overall air pollution on dementia risk and the potential effect modification by other risk factors remain to be clarified.

METHODS

We included 459 844 UK residents who were free of dementia and had data on the exposure to particulate matter (PM)2.5, PM2.5-10, PM10, NO2, and NOx during baseline recruitment. The combined exposure to various PMs and NOx was estimated by using an air pollution score. Hazard ratios (HRs) and 95% confidence intervals (CIs) for incident dementia were estimated by multivariable Cox models.

RESULTS

During a median 11.7 years follow-up, 5 905 incident cases of all-cause dementia were identified. With the exception of PM2.5-10, all other air pollutants were separately associated with a higher risk of all-cause dementia (all p-trend < .001) with generally similar associations for dementia subtypes. An increasing air pollution score was associated with higher risks of all-cause as well as individual dementia outcomes, with adjusted HRs (95% CI) of 1.27 (1.18, 1.37) for all-cause dementia, 1.27 (1.14, 1.43) for Alzheimer's disease, and 1.35 (1.16, 1.57) for vascular dementia when comparing the highest with the lowest quartile of the score (all p-trend < .001). These associations of air pollution score with dementia and its subtypes were observed among never and former smokers but not among current smokers (all p-interaction 
< .030).

CONCLUSION

Air pollution was associated with a higher risk of dementia among nonsmokers but not current smokers. Additional studies are required to confirm our findings and to explore the potential mechanisms underlying the possible effect modification by smoking status.

Healthy lifestyle and all-cause and cause-specific dementia in individuals with type 2 diabetes and the roles of diabetes duration and insulin use in UK Biobank cohort

AIMS

To examine the effect of a healthy lifestyle score derived from seven lifestyle factors recommended by the diabetes management guidelines on all-cause and cause-specific dementia in individuals with type 2 diabetes mellitus (T2DM), and how diabetes duration and insulin use status modify their association.

MATERIALS AND METHODS

This study analysed data of 459 840 participants from the UK Biobank. We used Cox proportional hazards models to estimate hazard ratios (HRs) and 95% confidence intervals for the association of an overall healthy lifestyle score with all-cause and cause-specific dementia of Alzheimer's disease, vascular dementia and non-Alzheimer non-vascular dementia.

RESULTS

Using diabetes-free participants who scored 5-7 as the reference group, in diabetes-free participants, we observed higher healthy lifestyle score was related to lower risk of all-cause and cause-specific dementia. However, in people with T2DM, those scored 2-3, 4 and 5-7 all had around the two-time risk of all-cause dementia (HR: 2.20-2.36), while those scored 0-1 had over a three-time risk (HR: 3.14, 95% confidence interval 2.34-4.21). A dose-response trend was observed with vascular dementia (each 2-point increase: 0.75, 0.61-0.93) and no significant association with Alzheimer's disease (0.95, 0.77-1.16). The reduced risk of all-cause and cause-specific dementia with higher lifestyle score was observed in patients with a diabetes duration less than 10 years, or in patients with no insulin use.

CONCLUSION

In people with T2DM, higher healthy lifestyle score was associated with lower risk of all-cause dementia. Diabetes duration and insulin use moderated the association between healthy lifestyle score and risk of dementia.

Onset age of diabetes and incident dementia: A prospective cohort study

BACKGROUND

Relationship between age at diagnosis of diabetes and dementia is lacking. The aim of the study was to investigate whether diabetes onset at a younger age was associated with a higher incidence of dementia.

METHODS

466,207 participants free of dementia in the UK biobank (UKB) were included in the analysis. Propensity score matching (PSM) was adopted to match diabetic and non-diabetic participants in different onset age of diabetes groups to evaluate onset age of diabetes and incident dementia.

RESULTS

Compared with non-diabetic participants, diabetes participants had an adjusted hazard ratio (HR) of 1.87 (95 % confidence interval [CI]: 1.73-2.03) for all-cause dementia, 1.85 (95 % CI: 1.60-2.04) for Alzheimer's disease (AD), and 2.86 (95 % CI: 2.47-3.32) for vascular dementia (VD). Among diabetic participants who reported onset age, the adjusted HRs for incident all-cause dementia, AD, and VD were 1.20 (95 % CI: 1.14-1.25), 1.19 (95 % CI: 1.10-1.29), and 1.19 (95 % CI: 1.10-1.28), respectively, per 10 years decrease in age at diabetes onset. After PSM, strength of association between diabetes and all-cause dementia increased with decreasing onset age of diabetes (≥60 years: HR = 1.47, 95 % CI: 1.25-1.74; 45-59 years: HR = 1.66, 95 % CI: 1.40-1.96; <45 years: HR = 2.92, 95 % CI: 2.13-4.01) after multivariable adjustment. Similarly, diabetic participants with onset age <45 years had greatest HRs for incident AD and VD, compared with their matched controls.

LIMITATIONS

Our results only reflect the characteristics of UKB participants.

CONCLUSIONS

Younger age at diabetes onset was significantly associated with a higher risk of dementia in this longitudinal cohort study.

The effects of long-term cumulative HbA1c exposure on the development and onset time of dementia in the patients with type 2 diabetes mellitus: hospital based retrospective study (2005-2021)

AIMS

We examine cumulative effect of long-term glycemic exposure in patients with type 2 diabetes mellitus (T2DM) on the development of dementia.

METHODS

The study involved 20,487 records of patients with T2DM identified in the electronic medical record at Severance Hospital, Korea. Cumulative HbA1c (AUC_HbA1c) and mean HbA1c over time (HbA1c_avg) as measures of long-term glycemic exposure were compared for the development of dementia and the time to dementia.

RESULTS

AUC_HbA1c and HbA1c_avg were significantly higher in patients who later developed dementia than in those who did not dementia (AUC_HbA1c: 56.2 ± 26.4 vs. 52.1 ± 26.1 %*Year; HbA1c_avg: 7.0 ± 1.0 vs. 7.3 ± 1.0 %). Odds ratio of dementia increased when HbA1c_avg was 7.2% (55 mmol/mol) or above, and when AUC_HbA1c was 42 %*Year (e.g., HbA1c 7.0% maintained for 6 years) or above. Among those who developed dementia, as HbA1c_avg increased, the time to dementia onset decreased (β = -380.6 days, 95% confidence interval [CI]: -416.2 to -345.0).

CONCLUSIONS

Our results indicate poorly controlled T2DM was associated with an increased risk of developing dementia, as measured by AUC_HbA1c and HbA1c_avg. Higher cumulative glycemic exposure may lead to developing dementia in a shorter time.

Microvascular Burden and Incident Heart Failure Among Middle-Aged and Older Adults With Type 1 or Type 2 Diabetes

OBJECTIVE

To examine the association between microvascular disease (MVD) and risk of heart failure (HF) among individuals with type 1 diabetes mellitus (T1DM) or type 2 diabetes mellitus (T2DM).

RESEARCH DESIGN AND METHODS

We included 1,713 and 28,624 participants with T1DM and T2DM, respectively, from the UK Biobank who were free of HF during enrollment. MVD burden reflected by the presence of retinopathy, peripheral neuropathy, and chronic kidney disease (CKD) at baseline was prospectively evaluated for the association with incidence of HF. Hazard ratios (HRs) and 95% CIs of HF were estimated by Cox regression models adjusted for multiple traditional risk factors.

RESULTS

There were 145 and 2,515 incident cases of HF recorded among participants with T1DM and T2DM, respectively, during a median follow-up of 11.5 years. The association between the number of MVD and HF was stronger among participants with T1DM than among those with T2DM (P for interaction <0.001). Compared with participants with no MVD, those with all three MVD had an adjusted HR (95% CI) of 11.37 (5.62, 22.99) in T1DM and 3.66 (2.74, 4.88) in T2DM. In T1DM, HRs (CIs) were 2.69 (1.75, 4.14) for retinopathy, 2.11 (1.38, 3.23) for peripheral neuropathy, and 2.21 (1.53, 3.18) for CKD. The corresponding estimates in T2DM were 1.24 (1.13, 1.36), 1.63 (1.36, 1.96), and 1.73 (1.59, 1.89), respectively.

CONCLUSIONS

While a heavier burden of MVD was associated with excess risk of HF both in T1DM and T2DM, the association was evidently more pronounced in T1DM.

Sugar-Sweetened Coffee Intake and Blood Glucose Management in Korean Patients with Diabetes Mellitus

One of the most frequently consumed beverages by Korean adults is 3-in-1 coffee (mixed coffee) with sugar and creamer. Hence, understanding the effect of sugar-sweetened coffee (SSC) consumption on blood sugar levels in patients with diabetes mellitus (DM) is important. This study was conducted using the Korea National Health and Nutrition Examination Survey data from 2008 to 2020. In total, 5671 patients with DM were included in the analysis. Coffee consumption patterns were assessed using a 24 h recall. Fasting blood glucose (FBG) and hemoglobin A1c (HbA1c) levels were used to evaluate whether patients reached the glycemic control targets defined by the Korean Diabetes Association. In total, 46.57% of patients with DM included in this analysis consumed SSC. Patients who frequently consumed SSC had significantly higher FBG and HbA1c levels than those who did not (both p for trend <0.01). In a multivariate logistic regression model, the odds ratios of not achieving the target FBG and HbA1c levels were 1.24 (95% confidence interval [CI]: 1.03−1.48, p for trend = 0.01) and 1.29 (95% CI: 1.05−1.58, p for trend = 0.009), respectively. Frequent consumption of SSC can cause difficulty in FBG and HbA1c management in patients with DM.

Duration of Diabetes, Glycemic Control, and Risk of Heart Failure Among Adults With Diabetes: A Cohort Study

CONTEXT

The influences of diabetes duration and glycemic control and their potential interplays on the risk of heart failure (HF) remain unclear.

OBJECTIVE

This work aimed to investigate the association of diabetes duration and glycemic control with the risk of HF.

METHODS

A total of 23 754 individuals with diabetes but without HF during the baseline recruitment of UK Biobank were included in this study. Duration of diabetes was self-reported, and the status of glycemic control was reflected by glycated hemoglobin A1c (HbA1c) levels. Their associations with incident HF were assessed using multivariate Cox models adjusting for traditional risk factors.

RESULTS

Duration of diabetes and HbA1c levels both were positively associated with the risk of HF. The hazard ratios (HRs) (95% CI) for diabetes durations of 5 to less than 10, 10 to less than 15, and 15 years or more were 1.09 (0.97-1.23), 1.13 (0.97-1.30), and 1.32 (1.15-1.53), respectively (vs < 5 years); and the HRs for HbA1c of 53.0 to less than 58.5 mmol/mol (7.0% to < 7.5%), 58.5 to less than 63.9 mmol/mol (7.5% to < 8.0%), and 63.9 mmol/mol or greater (8.0%) were 1.15 (1.02-1.31), 1.07 (0.91-1.26), and 1.46 (1.30-1.65), respectively (vs < 53.0 mmol/mol [7.0%]). Individuals with the longest disease duration (≥ 15 years) and poorer glycemic control (HbA1c  ≥ 63.9 mmol/mol [8.0%]) had a particularly higher risk of HF (P for interaction = .026).

CONCLUSION

The risk of HF among individuals with diabetes increases with a longer duration of diabetes and increasing HbA1c levels. This finding may contribute to the individualized prevention of HF in patients with diabetes if being considered in clinical practices and policy-making.

Long-term exposure to air pollution and risk of incident inflammatory bowel disease among middle and old aged adults

BACKGROUND

Epidemiological evidence regarding the associations between long-term exposure to air pollution and risk of incident inflammatory bowel disease (IBD) is scant.

OBJECTIVES

We examined the associations of various specific air pollutants with the risk of incident ulcerative colitis and Crohn's disease, two subtypes of IBD, among middle and old aged adults in the UK. We also explored potential susceptible subgroups.

METHODS

We used data from the UK Biobank study. Information on air pollution, including PM_2.5, PM_2.5-10, PM₁₀ as well as NO₂ and NO_x were estimated using the Land Use Regression model. Multivariable Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

After a median follow-up of 11.7 years, 1872 incident ulcerative colitis and 865 incident Crohn's disease cases were identified among 455,210 IBD-free participants. HRs (95% CIs) of ulcerative colitis associated with each 1 interquartile range (IQR) increase in PM_2.5, PM_2.5-10, PM₁₀, NO₂, and NO_x were 1.06 (1.01, 1.12), 1.03 (0.99, 1.08), 1.09 (1.03, 1.16), 1.12 (1.07, 1.19), and 1.07 (1.02, 1.12), respectively. The associations between all the air pollutants and risk of Crohn's disease were null. Smoking status and sex appeared to respectively modify the associations between some air pollutants and risk of ulcerative colitis and Crohn's disease.

CONCLUSION

Long-term exposure to various air pollutants was associated with the risk of incident ulcerative colitis but not Crohn's disease, highlighting the importance of developing environmental health strategy to reduce the burden of ulcerative colitis.

Ambient Air Pollutants and Incident Microvascular Disease: A Cohort Study

Little is known about the links between long-term exposure to air pollution and risk of incident microvascular disease (retinopathy, peripheral neuropathy, and chronic kidney disease). This study included 396 014 UK residents free of microvascular disease and macrovascular disease at baseline. Annual means of PM2.5, PM2.5-10, PM10, NO2, and NOx were assessed by land use regression models for each participant. A weighted air pollution score was generated from PM10 and NOx. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). During a median follow-up of 11.7 years, 14 327 composite microvascular disease occurred. While none of the air pollutants showed any statistically significant association with the risk of retinopathy, all the air pollutants were linked to the risk of peripheral neuropathy and chronic kidney disease. The adjusted-HRs (95% CIs) for each interquartile range increase in air pollution score were 1.07 (1.05, 1.09), 1.01 (0.94, 1.07), 1.13 (1.08, 1.19), and 1.07 (1.05, 1.10) for overall microvascular disease, retinopathy, peripheral neuropathy, and chronic kidney disease, respectively. In conclusion, long-term exposure to overall air pollution was associated with higher risks of peripheral neuropathy and chronic kidney disease among the general UK population.

Perception of benefits and barriers associated with dementia prevention behaviors among people with diabetes

Type 2 diabetes mellitus is a risk factor for developing dementia and a public health concern around the world. Identifying any predictive factors associated with diabetes-related dementia prevention behaviors are of value in helping to prevent dementia. From six community hospitals in Chiang Mai, Thailand, 182 people aged 30-60 years were enrolled in a cross-sectional study and completed a written questionnaire on dementia prevention behaviors and perceptions of health beliefs. Multiple linear regression analysis was applied to determine possible associations between dementia prevention behaviors and health belief perceptions. A high level of preventive behavior was associated with high perceptions of the benefits of, and barriers to, dementia prevention and longer duration of patients' diabetes. Findings indicate the predictive role of the two factors in the perception of health beliefs about dementia prevention behaviors among the participants. Although further testing with different samples and in different locations is warranted, education programs for health practitioners that integrate the findings of this study would be beneficial to improvement of dementia prevention behaviors in people with diabetes.