Associations Of Multiple Metabolic Factors With Metabolic Syndrome And Intracranial Atherosclerosis

Part One Association between multiple metabolic factors and metabolic syndromeBackgroundStroke is the main cause of mortality and morbidity in China.Metabolic syndrome(Met S)is a clustering of cardiometabolic abonormalities including abdominal obesity,elevated triglyceride(TG)levels,elevated blood pressure,low high-density lipoprotein cholesterol(HDL-C)levels and hyperglycemia.As the risk factor of stroke,Met S was correlated with cardiovascular disease,stroke and mortality.This study evaluated the ability of lipid accumulation product(LAP),visceral adiposity index(VAI)and the product of triglycerides and glucose(Ty G),three novel multiple metabolic factors,in identifying Met S with different criteria in middle-aged and elderly Chinese.Methods1.During June 2012-January 2013,consecutive patients(age?40 years)in the Department of Neurology were enrolled in our study.The criteria of Met S were based on the International Diabetes Federation(IDF)and the modified National Cholesterol Education Program's Adult Treatment Panel III(ATPIII).2.VAI,LAP and Ty G were computed based on published mathematical model.Multivariate logistic regression models were conducted to investigate whether VAI,LAP and Ty G were significantly correlated to Met S in all criteria based on the assigned cutoff points.3.The diagnostic ability for Met S in different criteria was defined by the area under the curve(AUC)in receiver operating characteristic(ROC)analyses.Results1.992 consecutive patients(age?40 years)were included in our study.The prevalence of Met S was 42.8%.2.ROC curve found VAI,LAP and Ty G were positively related to Met S in both criteria.The optimal cut-offs of VAI,LAP and Ty G for ATPIII and IDF criteria were 2.015,31.465,8.706 and 2.035,37.99,8.697,respectively.3.After adjustment of potential confounding factors,VAI,LAP and Ty G were significantly correlated with Met S in all criteria according to optimal cut-offs.4.For Met S,reliable predictive value was observed in different subgroups(age and sex).LAP demonstrated the greatest AUC in Met S with IDF definition(AUC=0.887,95% CI=0.852-0.922).ConclusionVAI,LAP and Ty G were reliable surrogate markers for identifying Met S in middle-aged and elderly Chinese.LAP could be a better parameter than VAI and Ty G for evaluating Met S in our study.PART TWO ASSOCIATION BETWEEN MULTIPLE METABOLIC FACTORS AND INTRACRANIAL ATHEROSCLEROSISChapter One:Associations of visceral adiposity index and lipid accumulation product with intracranial atherosclerosisBackgroundIntracranial atherosclerosis(ICAS)is an important cause of stroke in China.The visceral adiposity index(VAI)and the lipid accumulation product(LAP)have been proposed as multiple metabolic factors.Both the VAI and LAP are two reliable markers of central lipid accumulation,and their positive predictive values for cardiometabolic diseases have been demonstrated.However,the potential association of these markers with the risk of ICAS has not been previously investigated.Therefore,we investigated the association of the newly established LAP and VAI with ICAS in middle-aged and elderly Chinese.Methods1.From June 2012 to January 2013,consecutive patients?40 years of age underwent cerebral vascular imaging were enrolled in this study.2.The LAP and VAI were calculated in both sexes using equations.Patients were stratified according to sex-specific LAP tertiles or VAI tertiles.3.The diagnostic ability for ICAS in different markers was defined by the area under the curve(AUC)in receiver operating characteristic(ROC)analyses.4.Multivariate logistic regression models were used to evaluate the correlation of VAI and LAP with the risk of ICAS.Patients in the lowest tertile represented the reference category.Model one was adjusted for age,and Model two was adjusted for potential confounders.Results1.In total,845 patients were included in the study.The prevalence of ICAS gradually increased in females and in all patients with advancing tertiles of VAI or LAP.2.After adjusting for potential risks,both the VAI and LAP were related to ICAS in females [VAI: odds ratio(OR)=3.25,95% confidence interval(95% CI)=1.17–9.03,P=0.024;LAP: OR=4.11,95% CI=1.39–12.12,P=0.011;tertiles 3 vs.1].However,significant relationships were not found in males.3.In females,the sensitivity,specificity,and positive predictive value(PPV)were 74.7%,45.5%,and 84.4% for VAI(cut-off: 1.71)and 79.3%,40.5%,and 84.1% for LAP(cut-off: 23.99).ConclusionThe present study has shown that two surrogate metabolic markers,the VAI and LAP,may be associated with the risk of ICAS in females but not males among patients aged ?40 years.Chapter Two: Association between lipid ratios and ntracranial atherosclerosisBackgroundIntracranial atherosclerosis(ICAS)is a major cause of stroke in China.Lipid ratios are considered to be good markers for identifying vascular diseases.Nevertheless,studies focusing on the association between lipid ratios and ICAS are lacking.We wished to investigate the association of lipid ratios with ICAS in a Chinese population.Methods1.From December 2015 to January 2017,consecutive inpatients with ischemic stroke were included in our cross-sectional study.Intracranial and extracranial arteries were evaluated for atherosclerotic stenosis using digital subtraction angiography or computed tomography angiography.2.Lipid ratios [total cholesterol(TC)/high-density lipoprotein cholesterol(HDL-C),triglycerides(TG)/HDL-C,low-density lipoprotein cholesterol(LDL-C)/HDL-C,non-high-density lipoprotein cholesterol(non-HDL-C)/HDL-C,remnant cholesterol(RC)/HDL-C,apolipoprotein B(apo B)/apolipoprotein A-I(apo A-I),and apo B/HDL-C] were calculated.3.The diagnostic ability for lipid ratios was defined by the area under the curve(AUC)in receiver operating characteristic(ROC)analyses.Results1.658 consecutive inpatients with ischemic stroke were included in our final study.Apo B/apo A-I showed the most powerful relationship with ICAS after adjustment for potential confounding factors(first quartile vs.fourth quartile;OR: 2.32;95% CI: 1.44–3.73).2.This significant relationship was also present for other lipid ratios(TC/HDL-C,OR: 2.04,95% CI: 1.26–3.31;RC/HDL-C,OR: 1.64,95% CI: 1.01–2.65;non-HDL-C/HDL-C,OR: 2.04,95% CI: 1.26–3.31;LDL-C/HDL-C,OR: 1.92,95% CI: 1.19–3.10;apo B/HDL-C,OR: 2.28,95% CI: 1.41–3.71;fourth quartile vs.first quartile).3.These adjusted logistic regression analyses were repeated for extracranial atherosclerosis(ECAS),but a significant association between lipid ratios and ECAS was not observed.4.Analyses of ROC curves revealed that the apo B/apo A-I ratio had a peak AUC value for ICAS for the lipid level alone and lipid ratios.Overall,lipid ratios had higher AUC values than those for the lipid level alone for the identification of ICAS.ConclusionThe ratios of TC/HDL-C,LDL-C/HDL-C,RC/HDL-C,non-HDL-C/HDL-C,apo B/apo A-I and apo B/HDL-C were related significantly to ICAS risk.Compared with the other variables tested,the apo B/apo A-I ratio appeared to be better markers for identifying ICAS risk.