Dementia and in-hospital mortality: retrospective analysis of a nationwide administrative database of elderly subjects in Italy.

AIMS:  To evaluate the relationship between comorbidity and in-hospital mortality in elderly patients affected by dementia. METHODS: Data were obtained from the Italian Ministry of Health and included all discharge records from Italian hospitals concerning subjects aged ≥ 65 years admitted to acute Internal Medicine or Geriatrics wards between January 2015 and December 2016 (3.695.278 admissions). The variables analyzed included age, sex, and in-hospital death. Twenty-five homogeneous clusters of diseases were identified in discharge codes according to the ICD-9-CM classification. RESULTS: Patients with dementia represented 7.5% of the sample (n. 278.149); they were older, more often males (51.9%), and had a higher in-hospital mortality (24.3%) compared to patients without dementia (9.7%). Dementia per se doubled the odds of death (OR 1.98; 95% CI 1.95-2.00), independent of age, sex, and comorbidities. Seven clusters of disease (pneumonia, heart failure, kidneys disease, cancer, infectious diseases, diseases of fluids/electrolytes and general symptoms) were associated with increased in-hospital mortality, independent of the presence/absence of dementia. Among patients with dementia, heart failure, pneumonia and kidney disease on their own substantially doubled/tripled mortality risk. The risk increased from 10.1% (none of selected conditions), up to 28.9% when only one of selected comorbidities was present, rising to 52.3% (OR: 9.34; p < 0.001) when two or more comorbidities were simultaneously diagnosed, besides general symptoms. CONCLUSIONS: Our study confirmed an important increase of in-hospital mortality in older subjects with dementia. Despite a different comorbidity, the conditions associated with in-hospital mortality were substantially the same in patients with or without dementia. Heart failure, pneumonia, and kidney disease identified a high risk of in-hospital mortality among subjects with dementia.

Serum beta-secretase 1 (BACE1) activity increases in patients with mild cognitive impairment.

Beta-secretase 1 (BACE1) is considered as the key enzyme in amyloid-ß formation. Previous works suggest that high BACE1 activity may be present in brain, cerebrospinal fluid and serum of patients with late-onset Alzheimer's disease (LOAD) as well as mild cognitive impairment (MCI). Therefore, we evaluated whether serum BACE1 activity increases in MCI patients and is associated with the progression from MCI to dementia. BACE1 activity was measured in the serum of 259 MCI patients (162 amnestic-aMCI, 97 non-amnestic-naMCI) and 204 healthy Controls. After a median follow-up of 32 months (range: 10-153), 116 MCI progressed to dementia (87 aMCI and 29 naMCI). Serum BACE1 activity was higher in MCI compared with Controls (p < 0.001), and in aMCI with brain atrophy compared with naMCI without brain atrophy (p = 0.04). No difference in BACE1 activity emerged between converter and non-converter MCI, and this was true for both aMCI and naMCI. However, among aMCI with better cognitive performance (n. 163, MMSE score ≥24/30) those converting to dementia had higher BACE1 activity compared to stable ones (p = 0.05). This was not associated with an increased risk to develop dementia (hazard ratio: 1.65; 95% confidence interval: 0.67-4.01). In conclusion, serum BACE1 activity significantly increased in MCI patients (both amnestic and non-amnestic) compared with Controls. Moreover, higher serum BACE1 activity was observed only among aMCI with a better cognitive performance who progressed to dementia, suggesting that a dysregulation of this enzyme might be an early event primarily associated with neurodegeneration.