| Abstract: | We evaluated the association between allergic conditions and the risk of glioma in case–control and cohort studies published so far on this issue. A total of 12 studies (10 case–control and 2 cohort studies) were included in the analysis, involving 61 090 participants, of whom 6408 had glioma. When compared with non‐allergic conditions, the pooled odds ratio (OR) with any allergic conditions for glioma was 0.60 (95% CI: 0.52–0.69, P < 0.001), suggesting a significant negative association (protective effect) between allergy and glioma. Subgroup analysis showed that the ORs were 0.70 (95% CI: 0.62–0.79, P < 0.001), 0.69 (95% CI: 0.62–0.78, P < 0.001), and 0.78 (95% CI: 0.70–0.87, P < 0.001) for asthma, eczema, and hay fever, respectively. The significant association remained even after excluding the bias of proxy reporting (OR = 0.61; 95% CI: 0.50–0.75, P < 0.001). We conclude that allergic conditions may significantly reduce the risk of glioma. |
