Forskningsartikler

Late-life depression (LLD) has been linked to increased likelihood of subsequent dementia, although mechanisms responsible for this association remain largely unknown. One feature frequently observed in both LLD and dementia is elevated levels of plasma inflammatory markers. PRODE (Prognosis of Depression in the Elderly) is a prospective naturalistic study of patients with LLD (N=152; aged 60+). Patients were followed up for 3 years; follow-up data was available for 138 patients, and 36 (26.1%) developed dementia by year 3. Plasma inflammatory markers data were available for 136 patients at baseline for the following range of cytokines and chemokines: IL-1β, IL-1ra, IL-6, IL-10, IL-17a, IL-18, IL-33, TNFα, CD40L, IFN-γ, CCL-2 and CCL-4. Levels of plasma inflammatory markers were compared between 136 LLD patients and healthy controls (n=103), using first multiple linear regression (inflammatory markers as outcome) with stepwise adjustment, and then binary logistic regression with depression status (LLD vs controls) as outcome. Further, we explored whether inflammatory markers and clinical characteristics of LLD (age of onset, course) predicted progression from LLD to dementia using Cox regression. Levels of IL-1ra, IFN-γ, CCL-2, CCL-4 and IL-17a were significantly higher in LLD patients compared to controls. However, none of the inflammatory markers predicted progression from LLD to dementia. Among clinical features, only poor response to treatment significantly predicted higher risk of progression to dementia. In summary, this study replicated previous findings of an increase in inflammatory markers in LLD but did not find evidence they had increased risk of developing future dementia.

Dag Aarsland, Allan Young, Knut Engedal, John O’Brien, Geir Selbaek, Ane-Victoria Idland, Leiv-Otto Watne, Tom Borza, Mariia Bocharova

Background: Studies exploring the possible protective effect of coffee and tea consumption on dementia have shown inconsistent results so far. We aimed to investigate whether consumption of tea and different types of coffee at midlife are associated with dementia later in life and whether sex or ApoE4 influence such association.
Methods: We included 7381 participants from the Norwegian HUNT Study. Self-reported questionnaires assessed daily consumption of coffee and tea at baseline. After 22 years, individuals 70 years or older were screened for cognitive impairment.
Results: General coffee consumption and tea consumption was not associated with dementia risk. Compared to daily consumption of 0–1 cups of coffee, daily consumption of ≥8 cups of boiled coffee was associated with increased dementia risk in women (OR: 1.83, 95% CI: 1.10–3.04, p-value for trend = 0.03) and daily consumption of 4–5 cups of other types of coffee was associated with a decrease in dementia risk in men (OR: 0.48, 95% CI: 0.32–0.72, p-value for trend = 0.05). Furthermore, the association between boiled coffee and increased dementia risk was only found in ApoE4 non-carriers. Differences by sex or ApoE4 carrier status were not supported by strong statistical evidence for interaction. Tea consumption was not associated with dementia risk.
Conclusion: type of coffee may play a role in the direction of the association between coffee-drinking habits and dementia later in life.

Denise Abbel, Bjørn Olav Åsvold, Marit Kolberg, Geir Selbæk, Raymond Noordam and Håvard Kjesbu Skjellegrind

Introduction: There is a pressing need for non-invasive, cost-effective tools for early detection of Alzheimer’s disease (AD).

Methods: Using data from the Alzheimer’s Disease Neuroimaging Initiative (ADNI), Cox proportional models were conducted to develop a multimodal hazard score (MHS) combining age, a polygenic hazard score (PHS), brain atrophy, and memory to predict conversion from mild cognitive impairment (MCI) to dementia. Power calculations estimated required clinical trial sample sizes after hypothetical enrichment using the MHS. Cox regression determined predicted age of onset for AD pathology from the PHS.

Results: The MHS predicted conversion from MCI to dementia (hazard ratio for 80th versus 20th percentile: 27.03). Models suggest that application of the MHS could reduce clinical trial sample sizes by 67%. The PHS alone predicted age of onset of amyloid and tau.

Discussion: The MHS may improve early detection of AD for use in memory clinics or for clinical trial enrichment.

Highlights: A multimodal hazard score (MHS) combined age, genetics, brain atrophy, and memory. The MHS predicted time to conversion from mild cognitive impairment to dementia. MHS reduced hypothetical Alzheimer’s disease (AD) clinical trial sample sizes by 67%. A polygenic hazard score predicted age of onset of AD neuropathology.

Emilie T Reas, Alexey Shadrin, Oleksandr Frei, Ehsan Motazedi, Linda McEvoy, Shahram Bahrami, Dennis van der Meer, Carolina Makowski, Robert Loughnan, Xin Wang, Iris Broce, Sarah J Banks, Vera Fominykh, Weiqiu Cheng, Dominic Holland, Olav B Smeland, Tyler Seibert, Geir Selbaek, James B Brewer, Chun C Fan, Ole A Andreassen, Anders M Dale; Alzheimer’s Disease Neuroimaging Initiative