Estimating the association between systemic Interleukin-6 and mortality in the dialysis population. Re-analysis of the global fluid study, systematic review and meta-analysis

Background: Systemic inflammation, measured as circulating Interleukin-6 (IL-6) levels, is associated with cardiovascular and all-cause mortality in chronic kidney disease. However, this has not been convincingly demonstrated in a systematic review or a meta-analysis in the dialysis population. We provide such evidence, including a re-analysis of the GLOBAL Fluid Study.Methods: Mortality in the GLOBAL fluid study was re-analysed using Cox proportional hazards regression with IL-6 levels as a covariate using a continuous non-logarithmic scale. Literature searches of the association of IL-6 levels with mortality were conducted on MEDLINE, EMBASE, PyschINFO and CENTRAL. All studies were assessed for risk of bias using the QUIPS tool. To calculate a pooled effect size, studies were grouped by use of IL-6 scale and included in the meta-analysis if IL-6 was analysed as a continuous linear covariate, either per unit or per 10 pg/ml, in both unadjusted or adjusted for other patient characteristics (e.g. age, comorbidity) models. Funnel plot was used to identify potential publication bias. Results: Of 1886 citations identified from the electronic search, 60 were included in the qualitative analyses, and 12 had sufficient information to proceed to meta-analysis after full paper screening. Random effects meta-analysis of 11 articles yielded a pooled hazard ratio (HR) per pg/ml of 1.03, (95% CI 1.01, 1.03), = 81%. When the analysis was confined to seven articles reporting a non-adjusted HR the result was similar: 1.03, per pg/ml (95% CI: 1.03, 1.06), =92%. Most of the heterogeneity could be attributed to three of the included studies. Publication bias could not be determined due to the limited number of studies.Conclusion: This systematic review confirms the adverse association between systemic IL-6 levels and survival in people treated with dialysis. The heterogeneity that we observed may reflect differences in study case mix. Systematic Review Registration: PROSPERO - CRD42020214198

Estimating the association between systemic Interleukin-6 and mortality in the dialysis population. Re-analysis of the global fluid study, systematic review and meta-analysis

Abstract Background Systemic inflammation, measured as circulating Interleukin-6 (IL-6) levels, is associated with cardiovascular and all-cause mortality in chronic kidney disease. However, this has not been convincingly demonstrated in a systematic review or a meta-analysis in the dialysis population. We provide such evidence, including a re-analysis of the GLOBAL Fluid Study. Methods Mortality in the GLOBAL fluid study was re-analysed using Cox proportional hazards regression with IL-6 levels as a covariate using a continuous non-logarithmic scale. Literature searches of the association of IL-6 levels with mortality were conducted on MEDLINE, EMBASE, PyschINFO and CENTRAL. All studies were assessed for risk of bias using the QUIPS tool. To calculate a pooled effect size, studies were grouped by use of IL-6 scale and included in the meta-analysis if IL-6 was analysed as a continuous linear covariate, either per unit or per 10 pg/ml, in both unadjusted or adjusted for other patient characteristics (e.g. age, comorbidity) models. Funnel plot was used to identify potential publication bias. Results Of 1886 citations identified from the electronic search, 60 were included in the qualitative analyses, and 12 had sufficient information to proceed to meta-analysis after full paper screening. Random effects meta-analysis of 11 articles yielded a pooled hazard ratio (HR) per pg/ml of 1.03, (95% CI 1.01, 1.03), $${I}^{2}$$ = 81%. When the analysis was confined to seven articles reporting a non-adjusted HR the result was similar: 1.03, per pg/ml (95% CI: 1.03, 1.06), $${I}^{2}$$ =92%. Most of the heterogeneity could be attributed to three of the included studies. Publication bias could not be determined due to the limited number of studies. Conclusion This systematic review confirms the adverse association between systemic IL-6 levels and survival in people treated with dialysis. The heterogeneity that we observed may reflect differences in study case mix. Systematic Review Registration PROSPERO - CRD42020214198

Association between pet ownership and cardiovascular risks and mortality: a systematic review and meta-analysis

The aim of the study was to determine the association between pet ownership and cardiovascular risk factors and mortality. Electronic search was conducted through nine databases including PubMed for relevant publications reporting cardiovascular events and mortality among pet owners. Meta-analysis was used to pool the results. Of a total of 2818 reports screened, 26 studies were included in our systematic review and meta-analysis. Higher survival rate was observed in the pet owners group after pooling nonadjusted and adjusted hazard ratios for cardiovascular mortality at 0.73 [95% confidence interval (CI) 0.62–0.86] and 0.81 (0.68–0.97), respectively. A similar trend was observed for the pooled nonadjusted hazard ratio for overall mortality 0.73 (0.62–0.87) but not the adjusted hazard ratio 0.40 (0.04–3.78). Cat owners have a reduction in cardiovascular mortality but not overall mortality after pooling the adjusted hazard ratio 0.79 (0.63–0.99) and 1.04 (0.90–1.21), respectively. However, no significant association between dog owners and survival rate was observed for overall and cardiovascular-specific mortality. Pet owners had significantly lower heart rate (mean difference 95% CI: −2.32 (−3.07 to −1.57), mean arterial pressure −2.60 (−4.25 to −0.95) and SBP −1.69 (−3.06 to −0.31) but not DBP −0.23 (−1.05 to 0.60). No significant difference was observed between pet owners and nonpet owners in prevalence of hypertension. Our study draws attention to the beneficial effects of the human--pet bond; therefore, we recommend pet acquisition for better cardiovascular outcomes after controlling for zoonotics and pet-induced allergies