The Associations Between Plasma Choline And Betaine And Poor Prognosis In Patients With Ischemic Stroke

BackgroundStroke is the leading cause of disability and death among Chinese adults,with characteristics of higher rates of incidence,disability,mortality,recurrence and economic burden.Stroke is the first cause of the years of life loss,and has become a major global public health problem.Ischemic stroke is a complex disease caused by multiple pathophysiological pathways,and the known traditional risk factors are not effective in identifying high-risk patients with poor prognosis.Therefore,more reliable and sensitive prognostic markers still need to be explored.With the development of high-throughput technology,the relationships between choline pathway metabolites and cardiovascular diseases have aroused extensive attention.Previous studies have found that choline and betaine could exert neuroprotective effects by enhancing neuroplasticity,anti-oxidative damage,anti-inflammatory and improving endothelial function.However,populationbased evidence on choline and betaine with subsequent unfavorable outcomes after ischemic stroke is very limited.Based on the China Antihypertensive Trial in Acute Ischemic Stroke(CATIS),this study aimed to prospectively explore the relationships between circulating plasma choline and betaine with poststroke depression(PSD),cardiovascular events and stroke recurrence.Part I:We conducted a prospective cohort study to evaluate the associations between plasma choline and betaine and PSD.Part II:A nested case-control study was used to explore the relationships between circulating choline and betaine with cardiovascular events and stroke recurrence after ischemic stroke.PartⅠObjectiveA prospective cohort study was conducted to study the associations between plasma choline and betaine and PSD.MethodsIn this study,7 of the 26 participating hospitals in CATIS trial were randomly selected to continuously recruit patients,and a total of 612 patients with ischemic stroke were included.Baseline data on demographic characteristics,clinical features,medical history,medication use history and ischemic stroke subtype were obtained at admission using a standard questionnaire by trained interviewers.The levels of plasma choline and betaine were quantified on ultra-high-performance LC-MS/MS.The Hamilton Depression Scale(HRSD-24)was used by professional neurologists to assess depression status at 3 months after ischemic stroke.PSD was defined as the HRSD-24 score≥8.Logistic regression models were performed to estimate the relationships between plasma choline and betaine and the risk of PSD.We used restricted cubic splines to examine the shapes of the associations between plasma choline and betaine with PSD.Stratified analyses were carried out to examine whether the associations of plasma choline and betaine with PSD differed according to age(<65 vs≥65 years),sex,baseline National Institutes of Health Stroke Scale(NIHSS)score(<4 vs≥4),education years(<8 vs≥8 years).history of hypertension(yes or no)and randomized treatment(blood pressure reduction vs control).According to the median levels of plasma choline and betaine,patients were divided into four groups:low choline/low betaine,low choline/high betaine,high choline/low betaine and high choline/high betaine.We futher assessed the joint effects of plasma choline and betaine on the risk of PSD.In addition,area under the receiver operating characteristic curve(AUC),net reclassification index(NRI),and integrated discrimination improvement(IDI)were used to evaluate the predictive value of choline and betaine for PSD.ResultsDuring 3 months of follow-up,242(39.5%)participants were categorized as PSD.Patients with PSD had lower mean levels of plasma choline(15.29 μmol/L vs 16.40μmol/L.P=0.009)and betaine(55.46 μmol/L vs 59.62 μmol/L,P=0.03)than those without PSD.Compared with the lowest tertile,the multivariable adjusted ORs for highest tertile of choline and betaine were 0.54(95%CI 0.35-0.83)and 0.59(95%CI 0.38-0.92),respectively.Restricted cubic spline analysis showed inverse dose-dependent relationships between choline(P for linearity=0.001)and betaine(P for linearity=0.005)with PSD.The findings were similar across different subgroups.There were joint effects of choline and betaine on PSD.Compared with low choline/low betaine group,patients with high choline/high betaine had a significantly decreased risk of PSD(OR 0.53,95%CI 0.320.89).Adding plasma choline or betaine individually to the conventional model did not significantly improve discriminatory power,but choline(NRI 31.1%,P=0.0002;IDI 1.2%,P=0.006)and betaine(NRI 17.7%,P=0.03;IDI 0.8%,P=0.03)could improve the risk reclassification for PSD.When simultaneously adding plasma choline and betaine,the risk discrimination(AUC 0.693,P=0.04)and reclassification(NRI 25.6%,P=0.002;IDI 1.4%,P=0.003)for PSD were all significantly improved.ConclusionsPatients with elevated levels of choline and betaine had a lower risk of PSD.Plasma choline and betaine could significantly improve the risk stratification for PSD over the traditional model,suggesting choline and betaine may be effective predictive markers for PSD.Part ⅡObjectiveA nested case-control study was conducted to investigate the associations of plasma choline and betaine with cardiovascular events and stroke recurrence after ischemic stroke.MethodsBased on the CATIS trial,ischemic stroke patients with cardiovascular events were selected as the case group after 24 months follow-up,and the patients with no events were 1:1 matched for age(±1 year),sex and randomized treatment as the control group.Finally,a total of 323 cardiovascular events(including 264 recurrent strokes)and 323 controls were included.Trained and qualified neurologist or nurses used standardized questionnaires to collect baseline information.Plasma choline and betaine were measured at baseline by ultra-high-performance LC-MS/MS.The primary outcome was cardiovascular events at 24 months,and the secondary outcome was stroke recurrence.Conditional Logistic regression models were applied to explore the relationships between plasma choline and betaine with cardiovascular events and stroke recurrence at 24 months after ischemic stroke.Restricted cubic splines were used to examine the shapes of the associations between plasma choline and betaine with cardiovascular events and stroke recurrence.To test the robustness of our findings,we further performed sensitivity analyses using nonconditional Logistic regression models with adjustment for matching factors(age,sex,and randomized treatment)and other potential covariates.Paticipants were categorized as 4 groups by the median levels of plasma choline and betaine.Conditional Logistic regression model were used to analyze the combined effects of plasma choline and betaine on cardiovascular events and stroke recurrence after ischemic stroke with low choline/low betaine as the reference group.Furthermore,AUC,NRI,IDI were performed to evaluate the predictive power of plasma choline and betaine for cardiovascular events and stroke recurrence after acute ischemic stroke.ResultsPlasma choline and betaine were both inversely associated with cardiovascular events and stroke recurrence after ischemic stroke.After multivariable adjusted,the risk of cardiovascular events and stroke recurrence were 0.41(95%CI 0.25-0.66)and 0.43(95%CI 0.25-0.72)times higher in patients with the highest tertile of choline than in the lowest tertile.Compared with the lowest tertile,patients with the highest tertile of betaine had a 0.45(95%CI 0.29-0.71)and 0.46(95%CI 0.28-0.74)times higher risk of cardiovascular events and stroke recurrence,respectively.Multivariable-adjusted restricted cubic spline analyses suggested that there was evidence of nonlinear associations of choline and betaine levels with cardiovascular events and of choline with stroke recurrence(P for nonlinearity<0.01 for all).As choline and betaine levels elevated,the risks of adverse outcomes decreased and gradually leveled off.There also indicated an inverse linear relationship between betaine levels and stroke recurrence(P for linearity=0.001).Sensitivity analyses using nonconditional Logistic regression models further confirmed that plasma choline and betaine were associated with decreased risks of cardiovascular events and recurrent stroke after ischemic stroke.Compared with low choline/low betaine group,patients with high choline/high betaine had the lowest risk of cardiovascular events(OR 0.33,95%Cl 0.21-0.53)and stroke recurrence(OR 0.34,95%CI 0.20-0.56).Either the addition of choline(NRI 42.7%,P<0.001;IDI 2.8%,P<0.001;AUC 0.821,P=0.01)or betaine(NRI 46.4%,P<0.001;IDI 2.8%,P<0.001;AUC 0.820,P=0.03)alone or the addition of choline and betaine(NRI 50.2%,P<0.001;IDI 3.5%,P<0.001;AUC 0.823,P=0.01)together to the traditional model could significantly improve the risk prediction for cardiovascular events.Similarly,either the addition of choline(NRI 36.4%,P<0.001;IDI 2.6%,P<0.001;AUC 0.798,P=0.007)or betaine(NRI 39.4%,P<0.001;IDI 3.3%,P<0.001;AUC 0.801,P=0.01)alone or the addition of choline and betaine(NRI 43.9%,P<0.001;IDI 3.7%,P<0.001;AUC 0.804,P=0.004)together to the conventional model could significantly improve the risk prediction for stroke recurrence.ConclusionsPatients with higher levels of choline and betaine during the acute phase had decreased risks of cardiovascular events and stroke recurrence at 24 months after ischemic stroke.Incorporation plasma choline and betaine into conventional model significantly improved the risk prediction for cardiovascular events and stroke recurrence after ischemic stroke.