Persistent pain and cognitive decline in older adults: a systematic review and meta-analysis from longitudinal studies.

Both persistent pain and cognitive decline prevalence increase with advancing age and are associated with functional decline. However, the association of pain and cognitive decline has not been evaluated yet by a systematic assessment of longitudinal studies. We aimed to assess the association of persistent pain as a risk factor for cognitive decline in community older adults, using data from longitudinal studies in a systematic review and meta-analysis. Publications were identified using a systematic search on PubMed, EMBASE, and Cochrane Library databases from inception to June 2019. Because heterogeneity across studies was high, we used random-effects meta-analysis to calculate the pooled relative risk (RR) for the association between persistent pain and cognitive decline incidence. We investigated sources of heterogeneity among studies using meta-regression and stratified analyses. We included 10 prospective longitudinal studies with 57,495 participants with a mean age at the baseline ranging from 61.8 to 88.4 years and mean follow-up times ranging from 2.75 to 11.8 years. Persistent pain at baseline was not associated with the development of cognitive decline during the follow-up (pooled RR = 1.05, 95% confidence interval = 0.92-1.21). In sensitivity analyses, only length of follow-up time ≤4.5 years was associated with a higher risk of cognitive impairment (pooled RR = 1.19, 95% confidence interval = 1.10-1.28). Persistent pain was not associated with the incidence of cognitive decline.

Evidence for Host Epigenetic Signatures Arising From Arbovirus Infections: A Systematic Review.

Background: Arbovirus infections have steadily become a major pandemic threat. This study aimed at investigating the existence of host epigenetic markers arising from the principal arboviruses infections impacting on human health. We set to systematically review all published evidence describing any epigenetic modifications associated with infections from arboviruses, including, but not limited to, microRNAs, DNA methylation, and histone modifications. Methods: A comprehensive search was conducted using the electronic databases PubMed, Science Direct and Cochrane Library from inception to January 4th, 2018. We included reports describing original in vivo or in vitro studies investigating epigenetic changes related to arbovirus infections in either clinical subjects or human cell lines. Studies investigating epigenetic modifications related to the virus or the arthropod vector were excluded. A narrative synthesis of the findings was conducted, contextualizing comparative evidence from in vitro and in vivo studies. Results: A total of 853 unique references were identified and screened by two independent researchers. Thirty-two studies met the inclusion criteria and were reviewed. The evidence was centered mainly on microRNA and DNA methylation signatures implicated with secondary Dengue fever. Evidence for recent epidemic threats, such as the infections by Zika or Chikungunya viruses is still scant. Conclusions: Major epigenetic alterations found on arboviruses infections were miR-146, miR-30e and the Dicer complex. However, existing studies frequently tested distinct hypotheses resulting in a heterogeneity of methodological approaches. Whilst epigenetic signatures associated with arbovirus infections have been reported, existing studies have largely focused on a small number of diseases, particularly dengue. Validation of epigenetic signatures have an untapped potential, but concerted investigations are certainly required to deliver robust candidates of clinical utility for diagnosis, staging and prognosis of specific arboviral diseases.