The Role and Significance of Blood Lactate and FGF21 in the Diagnosis and Efficacy Monitoring of Mitochondrial Myopathy in Children
Objective:To analyze the role and significance of blood lactate and fibroblast growth factor 21(FGF21)in the diagnosis and efficacy monitoring of mitochondrial myopathy(ME)in children.Methods:A total of 141 subjects were enrolled in this study,including 47 children with ME(ME group),47 children with non-mitochondrial myopathies(muscle disease group),and 47 healthy children(control group),all of whom were admitted to Kunming Children's Hospital from August 2020 to February 2023.The ME group re-ceived dietary and exercise guidance,lamotrigine,idebenone,vitamin C,folic acid,and coenzyme Q10 for treatment.The efficacy was evaluated 3 months after treatment,and the ME patients were divided into con-trolled and uncontrolled subgroups according to the efficacy.Fasting blood samples were collected before treat-ment,1 month after treatment,and 3 months after treatment.Blood lactate levels were measured using the A-merican YSI 1500 SPORT blood lactate analyzer and matching reagent kit,and serum FGF21 levels were measured using enzyme-linked immunosorbent assay(ELISA)and enzyme-linked immunosorbent assay(ELISA).The levels of blood lactate and FGF21 in the three groups before treatment were compared.The in-teraction coefficient γ and OR values were used to analyze the interaction of blood lactate and FGF21 on the susceptibility of children to ME.The receiver operating characteristic(ROC)curve was used to analyze the value of blood lactate and FGF21 in the diagnosis of ME in children.The changes in blood lactate,FGF21,and Newcastle Mitochondrial Disease Assessment Scale(NMDAS)scores before and after treatment were com-pared between ME patients with different efficacies.Pearson correlation analysis was used to analyze the corre-lation between the decrease in blood lactate and FGF21 after 1 month and 3 months of treatment and the de-crease in NMDAS score.Results:Compared with the control group,the levels of blood lactate and FGF21 were elevated in the ME group(t=13.901,38.082,P<0.05);compared with the muscle disease group,the levels of blood lactate and FGF21 were also elevated in the ME group(t=12.734,35.696,P<0.05);there was no significant difference in blood lactate and FGF21 levels between the control group and the muscle dis-ease group(t=0.821,1.326,both P>0.05);interaction analysis showed that the OR value caused by the coexistence of blood lactate and FGF21 was 1350.500,the regression coefficient was 7.208,the interaction OR value was less than the product of the OR values of the two single factors,which was a sub-multiplicative model,γ=1.535>1,and the effect of blood lactate on FGF21 had a positive interaction effect;ROC curve showed that the AUC of blood lactate+FGF21 for the diagnosis of ME in children was 0.904,which was higher than that of blood lactate(0.839)and FGF21(0.719),with a diagnostic sensitivity of 78.72%and a specificity of 87.23%;the levels of blood lactate,FGF21 and NMDAS scores in patients with controlled dis-ease were lower than those in patients with uncontrolled disease after 1 month and 3 months of treatment(P<0.05);correlation analysis showed that the decrease in blood lactate and FGF21 after 1 month and 3 months of treatment was positively correlated with the decrease in NMDAS score after 1 month and 3 months of treat-ment(P<0.05).Conclusion:The blood lactate and FGF21 levels in children with ME are elevated,and there is a positive interaction between the two,which is closely related to the condition and efficacy of the dis-ease.