Correlation Analysis Between Plasma Lactic Acid And Insulin Resistance In OSAHS

BackgroundIsulin resistance and glucose metabolism dysfunction is closely related to Obstructive sleep apnea hypopnea syndrome(OSAHS).OSAHS and type 2 diabetes are independent risks factor for each other,and insulin resistance is positively correlated with AHI.Lactic acid is a marker of oxidative metabolism disorder,while fasting plasma lactic acid level is increased in OSAHS.Clinical researches have shown that plasma lactic acid is strongly associated with the occurrence of type 2 diabetes and may be a factor to predict the risk of type 2 diabetes,and lactic acid is correlated with insulin resistance(IR).Therefore,the objective of our study was to investigate the fasting plasma lactic acid level in OSAHS,and the relationship between fasting plasma lactic acid and the severity of the OSAHS,as well as investigating the relationship between fasting plasma lactic acid level and insulin resistance in OSAHS patients.MethodsThere are 131 patients in sleep center of Southern Medical University NanFang Hospital of southern medical university with snoring or apnea during sleep were recuited from July 2019 to January 2021,whoes general demographic information wre collected,including gender,age,height,weight,BMI,neck circumference,chest circumference,abdominal circumference.After the whole night of Polysomnography(PSG),apnea and hyponea episodes per hour of sleep(apnea/hyponea index:AHI),minimum and average pulse oxygen were recorded by PSG,and fasting plasma lactic acid,fasting insulin,fasting blood glucose,triglycerides(TG),total cholesterol(CHOL),low density lipoprotein(LDL),high density lipoprotein(HDL)and other indexes after fasting for 8 hours were measured in the next day morning.After then a standard 75g oral glucose tolerance test was performed.OSAHS was disgnose for AHI>5 times per hour,and insulin resistance(IR)was defined as Homeostasis model assessment(HOMA)>2.7.IBM SPSS Statistics 26 software was used for statistical analysis.Normal test and homogeneity test of variance were performed for continuous data.One-way analysis of variance(ANOVA)and LED test were used for comparison between groups.Pearson’s or Spearman’s correlation analysis was used for identifying the correlation between two variables.Binary Logistic regression analysis was applied to identify the correlation between IR and others variables.ResultsAccording to the severity of OSAHS,patients were divided into 4 groups:nonOS AHS group(control group,AHI<5),mild OSAHS group(5≤AHI<15),moderate OSAHS group(15≤AHI<30)and severe OSAHS group(AHI≥30).HOMA-IR>2.7 was defined as insulin resistance group,and HOMA-IR≤2.7 was non-insulin resistance group.According to the severity of OSAHS,the analysis of demographic data showed that the BMI,neck circumference,chest circumference and abdominal circumference of the severe OSAHS group were higher than those of the control group and the mild group.Fasting plasma lactate level,HOMA-IR and lipid indexes in the severe OSAHS group were significantly higher than those in the control group and the mild OSAHS group(P<0.05),and both fasting plasma lactate level and HOMA-IR were related to the severity of the disease.Among the subgroup analyzing,plasma lactic acid was significantly higher in the insulin resistant group(HOMA-IR>2.7)than in the non-insulin resistant group(HOMA-IR(2.7).Similarly,HOMA-IR was significantly increased in the high lactic acid level group(plasma lactic acid)2.2 mmol/L)(P<0.05).Finally,Bariate Logistic regression analysis showed that the regression coefficient β of BMI was 0.181(P=0.024),and TG was 1.492(P=0.000),and gender was 1.671(P=0.019).There was no independent correlation between plasma lactate level and insulin resistance(HOMA-IR).The main factors affecting insulin resistance were BMI,triglyceride and gender.ConclusionFasting plasma lactic acid level was increased in severe OSAHS group,which was correlated with AHI,BMI and HOMA-IR.After adjusting for gender,age and AHI,fasting plasma lactic acid was not an independent risk factor for HOMA-IR,but gender,TG and BMI were independently risk factors for HOMA-IR,and lipid metabolic disorder may be play a role in the pathogenesis of insulin resistance in OSAHS.