Background: optimal blood pressure targets in older adults are controversial. Objective: to investigate whether the relation of blood pressure with mortality in older adults varies by age, functional and cognitive status. Design: longitudinal geriatric outpatient cohort. Setting: Milan Geriatrics 75+ Cohort Study. Subjects: one thousand five hundred and eighty-seven outpatients aged 75 years and over. Methods: the relations of systolic (SBP) and diastolic blood pressure (DBP) with mortality risk were analysed using Cox proportional hazards models. Blood pressure, Mini-Mental State Examination (MMSE) and Basic Activities of Daily Living (ADL) were assessed at baseline. All analyses were adjusted for socio-demographic factors, co-morbidities and medications. Results: one thousand and forty-six patients died during 10-year follow-up. The relationships of SBP and DBP with mortality risk were U-shaped; SBP of 165 mmHg and DBP of 85 mmHg were associated with the lowest mortality. Patients with SBP < 120 mmHg and patients with SBP 120–139 mmHg had 1.64-fold (95% confidence intervals, CI 1.21–2.23) and 1.32-fold (95% CI 1.10–1.60) higher mortality risk than patients with SBP 160–179 mmHg (P values 0.001 and 0.004, respectively). In patients with SBP below 180 mmHg, higher SBP was associated with lower mortality in patients with impaired ADL and MMSE but not in those with preserved ADL and/or MMSE (P for interaction 0.033). Age did not modify the correlation of SBP with mortality. Conclusions: the correlations of SBP and DBP with mortality were U-shaped. Higher SBP is related to lower mortality in subjects with impaired ADL and MMSE. ADL and MMSE may identify older subjects who benefit from higher blood pressure.
Background: Heart rate variability (HRV) is a reliable and convenient method to assess autonomic function. Cross-sectional studies have established a link between HRV and cognition. Longitudinal studies are an emerging area of research with important clinical implications in terms of the predictive value of HRV for future cognition and in terms of the potential causal relationship between HRV and cognition. However, they have not yet been the objective of a systematic review. Therefore, the aim of this systematic review was to investigate the association between HRV and cognition in longitudinal studies. Methods: The review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The Embase, PsycINFO and PubMed databases were searched from the earliest available date to 26 June 2023. Studies were included if they involved adult human subjects and evaluated the longitudinal association between HRV and cognition. The risk of bias was assessed with the Newcastle–Ottawa Scale for Cohort Studies. The results were presented narratively. Results: Of 14,359 records screened, 12 studies were included in this systematic review, with a total of 24,390 participants. Two thirds of the studies were published from 2020 onwards. All studies found a longitudinal relationship between HRV and cognition. There was a consistent association between higher parasympathetic nervous system (PNS) activity and better cognition, and some association between higher sympathetic nervous system activity and worse cognition. Also, higher PNS activity persistently predicted better executive functioning, while data on episodic memory and language were more scant and/or controversial. Conclusions: Our results support the role of HRV as a biomarker of future cognition and, potentially, as a therapeutic target to improve cognition. They will need confirmation by further, more comprehensive studies also including unequivocal non-HRV sympathetic measures and meta-analyses.
The oral–gut microbiota axis is a relatively new field of research. Although most studies have focused separately on the oral and gut microbiota, emerging evidence has highlighted that the two microbiota are interconnected and may influence each other through various mechanisms shaping systemic health. The aim of this review is therefore to provide an overview of the interactions between oral and gut microbiota, and the influence of diet and related metabolites on this axis. Pathogenic oral bacteria, such as Porphyromonas gingivalis and Fusobacterium nucleatum, can migrate to the gut through the enteral route, particularly in individuals with weakened gastrointestinal defenses or conditions like gastroesophageal reflux disease, contributing to disorders like inflammatory bowel disease and colorectal cancer. Bile acids, altered by gut microbes, also play a significant role in modulating these microbiota interactions and inflammatory responses. Oral bacteria can also spread via the bloodstream, promoting systemic inflammation and worsening some conditions like cardiovascular disease. Translocation of microorganisms can also take place from the gut to the oral cavity through fecal–oral transmission, especially within poor sanitary conditions. Some metabolites including short-chain fatty acids, trimethylamine N-oxide, indole and its derivatives, bile acids, and lipopolysaccharides produced by both oral and gut microbes seem to play central roles in mediating oral–gut interactions. The complex interplay between oral and gut microbiota underscores their crucial role in maintaining systemic health and highlights the potential consequences of dysbiosis at both the oral and gastrointestinal level. Some dietary patterns and nutritional compounds including probiotics and prebiotics seem to exert beneficial effects both on oral and gut microbiota eubiosis. A better understanding of these microbial interactions could therefore pave the way for the prevention and management of systemic conditions, improving overall health outcomes.
17 August 2015 in Journal of the American Geriatrics Society