Forskningsartikler

Abstract

Background
Infections may contribute to Alzheimer’s disease (AD) pathogenesis. Prior studies on the relationship between Helicobacter pylori (H. pylori) infection and AD or dementia have shown differing results.ObjectiveWe investigated whether H. pylori serology is associated with the risk of AD and dementia in the Trøndelag Health Study (HUNT).
Methods
The HUNT cohort study measured serum H. pylori antibody titers using the Pyloriset EIA-IgG test. 22 years after baseline serum sampling, cognitive assessments were conducted using standardized tests and proxy interviews. We performed logistic regression (n = 1364) adjusted for sex and age to estimate odds ratios for cognitive outcomes. Subgroup analyses were stratified by sex, age, Apolipoprotein E4 (APOE ε4) carrier status and high sensitivity serum C-reactive protein levels and sensitivity analyses further adjusted for lifestyle and co-morbidity risk factors. Cox regression models (n = 4689) were used to estimate hazard ratios for all-cause mortality.
Results
H. pylori titers were not associated with AD (OR 0.99 per 1 SD higher titer, 95% CI 0.82-1.20) or dementia (OR 0.98, 95% CI 0.84-1.15). There were no associations between H. pylori seropositivity (≥ 300 titers) and AD (OR 1.10, CI 0.75-1.63) or dementia (OR 0.96, CI 0.68-1.32). Stratifications by sex, age, CRP, or APOE ε4 genotype and adjusting for additional covariates showed no associations. All-cause mortality was higher with H. pylori positivity (HR 1.07, CI 1.03-1.11).
Conclusions
H. pylori was not associated with later AD or dementia in this study. The relationship between specific versus multi-pathogenic infection burden and neurodegenerative diseases warrants further clarification.

Pieta T Kelsey, Geir Selbæk, Hugo Lövheim, Bjørn Olav Åsvold, Kristian Hveem, Brooke N Wolford & Håvard K Skjellegrind

Abstract

Introduction: Efficient and cost-effective diagnostic tools for supporting dementia assessment are increasingly important. We aimed to evaluate whether providing neuroradiologists with volumetric data from an automatic MRI software, NeuroQuant, enhanced the diagnostic accuracy of their visual MRI assessment.

Methods: Two neuroradiologists assessed brain MRIs from 366 patients (mean age 67.5 years, SD 9.2, and 52% females) with subjective cognitive decline (SCD, n 79), mild cognitive impairment (MCI, n 86), or dementia (n 201). The MCI and dementia patients were further diagnosed according to an etiology of Alzheimer’s disease (AD, n 217) versus non-AD (n 70). In random order the neuroradiologists visually evaluated medial temporal lobe atrophy (MTA, scale 0-4) with and without having access to the NeuroQuant report of age and sex adjusted volumetric percentiles of the hippocampus. Receiver operating characteristics (ROCs) analyses were conducted to calculate the area under the curves (AUCs) for the visual MTA, the automated NeuroQuant percentile, and the combined NeuroQuant-assisted MTA in discriminating dementia from SCD and AD from non-AD.

Results: The AUC of the visual MTA for dementia versus SCD discrimination increased slightly but not significantly when the neuroradiologists were provided with NeuroQuant results (AUC 0.76-0.79, p 0.28). Yet, the isolated NeuroQuant evaluation reached the highest accuracy (AUC 0.85, p < 0.001), significantly better than the MTA assessment (p 0.002) and the NeuroQuant-assisted MTA (p 0.04). Only the isolated NeuroQuant assessment discriminated AD from non-AD (AUC 0.60, p 0.006).

Conclusion: On the basis of our findings, we suggest an increased use of clinically approved automatic volumetry methods in radiological departments.

Karin Persson, Hanneke F M Rhodius-Meester, Trine Holt Edwin, Anne-Brita Knapskog, Peter Bekkhus-Wetterberg, Geir Selbæk, Knut Engedal, Till Schellhorn

Abstract

Bernt Bratsberg, Jennifer R Harris, Vegard Skirbekk, Yaakov Stern, Asta Kristine Håberg, Geir Selbæk, Bjørn Heine Strand, Trine Holt Edwin