In older adults undergoing hip fracture surgery, duration of POD is an important prognostic factor for 6-month mortality. Efforts to reduce duration of POD are therefore crucial for these individuals.

Objective-Several Studies claim that psychophysical stress and depression contribute significantly to cardiovascular disease (CVD) development. The aim of our research is to discover and analyse a possible relationship between two psychosocial disorders (Depression and Perceived Mental Stress) and traditional cardiovascular risk markers.Methods-We selected 106 subjects (M:58, F:48), mean age 79,5 ± 3,8 years old, from The Massa Lombarda Project, an epidemiological study including 7000 north Italian adult subjects. We carried out anamnesis, clinical and blood tests. Then we administered the Perceived Stress Questionnaire (PSQ range-score 0-1) and the Self Rating Depression Scale (SRDS range score 50-70 Z), as validated instruments for depression and stress evaluation, which focus on the individual's subjective perception and emotional response. Statistical descriptive and inferential analysis of data collected were performed.

a b s t r a c tThe aim of the study was to investigate the association between postoperative delirium (POD) and in vivo markers of Alzheimer's disease pathology in nondemented hip fracture surgery patients. POD was assessed with the Confusion Assessment Method. Amyloid load was quantified on 18 F-Flutemetamol positron emission tomography images as standardized uptake value ratio. Secondary outcome measures were gray matter volumes, white matter integrity, and functional connectivity at rest. All the patients with POD (PODþ, N ¼ 5) were amyloid negative (standardized uptake value ratio <0.59), whereas 6 out of 11 patients without POD (PODÀ) showed brain amyloid positivity. PODþ compared to PODÀ displayed: lower gray matter volumes in the amygdala (p ¼ 0.003), in the middle temporal gyrus and in the anterior cingulate cortex (p < 0.001), increased diffusivity in the genu of the corpus callosum and in the anterior corona radiata (p < 0.05), and higher functional connectivity within the default mode network (p < 0.001). POD patients showed altered gray and white matter integrity in the fronto-limbic regions in absence of brain amyloidosis. Based on this preliminary investigation, delirium pathophysiology might be independent of Alzheimer's disease. Future studies on larger samples are needed to confirm this hypothesis.

Hyperactive delirium was the most common POD psychomotor subtype, but hypoactive and mixed POD were associated with 6-month mortality risk. Moreover, the risk of death 6 months after surgery increased for both subgroups (hypoactive and mixed) with increasing duration of POD.