Higher Serum Fibroblast Growth Factor-23 Levels and the Risk of Stroke and Its Subtypes: Evidence From a Meta-Analysis of Prospective Studies.

BACKGROUND: Epidemiologic studies have indicated conflicting associations of fibroblast growth factor-23 (FGF23) with the risk of stroke. To this end, a meta-analysis of prospective studies was conducted to assess the association. METHODS: Relevant studies were identified by searching PubMed and Embase databases to March 23, 2018. Relative risks (RRs) with 95% confidence intervals (CIs) were combined with the fixed-effects model or random-effects model according to the degree of heterogeneity. Moreover, stratified analyses and sensitivity analysis were carried out for further analysis. RESULTS: Seven prospective studies involving 1988 stroke events among 18048 participants were eligible for our meta-analysis. The combined RRs for total stroke were 1.29 (95% CI: 1.10, 1.52) for the highest versus lowest category of FGF23, with low heterogeneity among studies (Pheterogeneity = 0.38, I2 = 6.1%). Stratified analyses showed that the combined RRs for ischemic stroke (IS) and hemorrhagic stroke (HS) risk were 1.12 (95% CI: 0.92, 1.37) and 2.63 (95% CI: 1.61, 4.30), respectively. In the stratification by geographic areas, the association between higher FGF23 and stroke was similar with studies performed in the United States (RR = 1.24, 95%CI: 1.03, 1.49) and Europe (RR = 1.88, 95%CI: 0.77, 4.55); however, only the results in the United States were statistically significant. Sensitivity analysis indicated the combined results were robust. CONCLUSIONS: Our meta-analysis showed that higher FGF23 levels were associated with an increased risk of stroke. The positive association consistently existed in HS rather than in IS. Further studies are required to confirm these causal associations and to investigate the mechanisms.

Diabetes mellitus and the risk of aneurysmal subarachnoid haemorrhage: A systematic review and meta-analysis of current evidence.

Objective This systematic review aimed to define the relationship between diabetes mellitus (DM) and the risk of aneurysmal subarachnoid haemorrhage (aSAH). Methods Studies associated with DM and aSAH published until March 2016 were retrieved from Pubmed, Embase, Web of Science, and Cochrane Library databases. A random-effects model was used to calculate the relative risks (RRs) with 95% confidence intervals (CIs). Results Eighteen observational studies were retrieved. The overall RRs for DM and aSAH were RRs = 0.59 (0.44, 0.79), with moderate heterogeneity ( I2 = 55.7%, Pheterogeneity = 0.000). Subgroup analysis by study quality revealed a reduced association between DM and aSAH risk in high quality studies only (RRs = 0.40, 95% CI: 0.29, 0.56; I2 = 0.0%, Pheterogeneity = 0.549), therefore study quality may be a source of heterogeneity. Conclusion A potential decreased risk of aSAH in DM patients was found in high quality studies. Further studies are required to confirm this causal relationship and to investigate the biological mechanisms.