Objective: To examine the dose-response association between cardiorespiratory fitness ( CRF ) and the risk of cardiovascular and cerebrovascular diseases. Methods: A joint search was performed in Chinese and English electronic databases, including China National Knowledge Infrastructure ( CNKI ) , Wanfang Data, VIP, CBM, PubMed, Embase and Web of Science, to retrieve publications reporting the correlation between CRF and the risk of cardiovascular and cerebrovascular diseases until May, 2021. The pooled risk was estimated using the random effects model, and the dose-response association was evaluated using restricted cubic splines. The source of heterogeneity was assessed by subgroup analysis, and the stability of the results was tested by the trim-and-fill method, while the publication bias was assessed using funnel plots. Results: Totally 37 280 literatures were identified, and 23 eligible studies were finally included in the analysis, which covered 2 605 622 subjects. There were 22 publications identified as high-quality. Meta-analysis revealed that the pooled risk of cardiovascular and cerebrovascular diseases reduced by 42% in the highest CRF group relative to the lowest CRF group ( OR=0.58, 95%CI: 0.52-0.65 ), and a one metabolic equivalent ( MET ) increase in CRF caused a 10% reduction in the pooled risk of cardiovascular and cerebrovascular diseases ( OR=0.90, 95%CI: 0.88-0.92 ). There was a negative linear correlation between CRF and the incidence of cardiovascular and cerebrovascular diseases ( P=0.396 ). Subgroup analysis identified gender, sample size and study regions as possible sources of heterogeneity, and sensitivity analysis showed that the study results were stable. Conclusions There is a negative linear correlation between CRF and the risk of cardiovascular and cerebrovascular diseases, and an increase in CRF may reduce the risk of cardiovascular and cerebrovascular diseases.

This study reported a 50-year-old female patient who was diagnosed with anti-IgLON family member 5(anti-IgLON5)antibody-related encephalopathy,presented with cognitive and sleep disorders,autonomic dysfunction and seizures,positive serum IgLON5 antibody but negative cerebro-spinal fluid IgLON5 antibody,negative human leukocyte antigen(HLA)by genetic testing,and was diagnosed as anti-IgLON5 antibody-related encephalopathy.After hospital admission,the patient was given intravenous methylprednisolone combined with immunoglobulin immunotherapy,donepezil for improvement of cognition,sodium valproate and oxcarbazepine for prevention and treatment of epilep-tic seizures,and finally her symptoms improved significantly.

This study reported a 50-year-old female patient who was diagnosed with anti-IgLON family member 5(anti-IgLON5)antibody-related encephalopathy,presented with cognitive and sleep disorders,autonomic dysfunction and seizures,positive serum IgLON5 antibody but negative cerebro-spinal fluid IgLON5 antibody,negative human leukocyte antigen(HLA)by genetic testing,and was diagnosed as anti-IgLON5 antibody-related encephalopathy.After hospital admission,the patient was given intravenous methylprednisolone combined with immunoglobulin immunotherapy,donepezil for improvement of cognition,sodium valproate and oxcarbazepine for prevention and treatment of epilep-tic seizures,and finally her symptoms improved significantly.