Neural networks involved in nausea in adult humans: A systematic review

Nausea is a common clinical symptom, poorly managed with anti-emetic drugs. To identify potential brain regions which may be therapeutic targets we systematically reviewed brain imaging in subjects reporting nausea. The systematic review followed PRISMA statements with methodological quality (MINORS) and risk of bias (ROBINS-I) assessed. Irrespective of the nauseagenic stimulus the common (but not only) cortical structures activated were the inferior frontal gyrus (IFG), the anterior cingulate cortex (ACC) and the anterior insula (AIns) with some evidence for lateralization (Left-IFG, Right-AIns, Right-ACC). Basal ganglia structures (e.g., putamen) were also consistently activated. Inactivation was rarely reported but occurred mainly in the cerebellum and occipital lobe. During nausea, functional connectivity increased, mainly between the posterior and mid- cingulate cortex. Limitations include, a paucity of studies and stimuli, subject demographics, inconsistent definition and measurement of nausea. Structures implicated in nausea are discussed in the context of knowledge of central pathways for interoception, emotion and autonomic control. Comparisons are made between nausea and other aversive sensations as multimodal aversive conscious experiences.

Handgrip strength and respiratory disease mortality: Longitudinal analyses from SHARE

BACKGROUND

While the association between handgrip strength and all-cause mortality is more deeply explored, no previous studies have been specifically focused on handgrip strength and respiratory disease mortality. The purpose of the study was to investigate the association between handgrip strength and respiratory disease mortality in a large representative sample.

METHODS

Individuals aged 50 or over from 27 European countries and Israel participated in this longitudinal study. Data on handgrip strength and all-cause and respiratory disease mortality were retrieved from the Survey of Health, Ageing and Retirement in Europe (SHARE) waves 1, 2, 4, 5, 6 and 7. We estimated the sub hazard ratios (SHRs) for respiratory disease mortality using a Fine-Gray sub-distribution method with both time-varying exposure and covariates and mortality due to other causes as competing risk. Furthermore, we assessed dose-response associations of handgrip strength (modelled as a continuous exposure) with respiratory disease mortality using restricted cubic splines and estimated hazard ratios (HRs).

RESULTS

We included 60,883 men and 74,904 women with a mean age of 63.6 (SD 9.7) years at study entry. During a median (interquartile range) of 7.4 years of follow-up 565 (0.4%) participants died due to respiratory diseases. The increase of 1 single kg of handgrip strength showed a 6% incidence reduction on respiratory disease mortality (SHR, 0.94; 95%CI, 0.92-0.96) after adjusting for potential confounders. Furthermore, each kg increase of handgrip strength reduced respiratory disease mortality risk in a dose-response fashion and a significant threshold for values of 41 kg (HR, 0.49; 95%CI, 0.26-0.92) and higher was identified.

CONCLUSIONS

Higher handgrip strength is associated with lower mortality due to respiratory disease. Intervention studies are needed to determine whether strength training in respiratory disease patients can prevent premature mortality.