Relationship between hemoglobin A1c variability index and vitamin D level in patients with type 2 diabetes mellitus
MA Yan
MAO Peijun
TIAN Xiongtao
YU Gaole
LIU Chunfang
LIU Wei
MEI Chunli
LI Jie
Abstract：Objective To analyze the relationship between hemoglobin A1c variability index(HGI)and vitamin D(VD)level in patients with type 2 diabetes mellitus(T2DM).Methods A total of 1,014 T2DM patients were enrolled.General data and laboratory indicators were collected,including gender,age,diastolic blood pressure,systolic blood pres-sure,heart rate,body mass index(BMI),diabetes duration,history of hypertension,history of hyperlipidemia,family history of diabetes,smoking history,drinking history,25-hydroxyvitamin D[25-(OH)D],fasting plasma glucose(FPG),hemoglobin A1c(HbA1c),alanine aminotransferase(ALT),aspartate aminotransferase(AST),alkaline phos-phatase(ALP),gamma-glutamyl transferase(GGT),blood urea nitrogen(BUN),creatinine(Cr),triglyceride(TG),to-tal cholesterol(TC),high-density lipoprotein cholesterol(HDL-C),low-density lipoprotein cholesterol(LDL-C),urinary microalbumin,estimated glomerular filtration rate(eGFR),hemoglobin(Hb),red blood cells(RBC),white blood cells(WBC),platelets(PLT),albumin(ALB),uric acid(UA),etc.Linear regression analysis was performed on HbA1c and FPG data of 1,014 patients to calculate the regression equation,and then the patients'HGI was calculated:HGI=mea-sured HbA1c-predicted HbA1c.According to the HGI,1,014 patients were divided into the low HGI group,medium HGI group,and high HGI group by tertile method.Spearman rank correlation analysis was used to analyze the correlation between HGI and 25(OH)D levels in T2DM patients,and the correlation between HGI and 25(OH)D levels in male and female T2DM patients was analyzed after stratification by gender.Restricted cubic spline(RCS)method was used to ana-lyze the non-linear relationship between HGI and 25(OH)D,and the non-linear relationship between HGI and 25(OH)D levels in male and female T2DM patients was analyzed after stratification by gender.Results The age,systolic blood pressure,and diabetes duration of patients in the high HGI group were lower than those in the low HGI group and the medi-um HGI group(all P<0.05).HbA1c in the medium HGI group was higher than that in the low HGI group,and WBC was lower than that in the low HGI group(both P<0.05);25(OH)D,ALB,and UA in the high HGI group were lower than those in the low HGI group and the medium HGI group(all P<0.05),while FPG,HbA1c,eGFR,RBC,and WBC were higher than those in the low HGI group and the medium HGI group(all P<0.05);AST and Cr in the high HGI group were lower than those in the low HGI group(both P<0.05),while LDL-C and PLT were higher than those in the low HGI group(both P<0.05).Spearman rank correlation analysis showed that HGI was negatively correlated with 25(OH)D level in T2DM patients(r=-0.823,P<0.01).Further stratified analysis showed that HGI was negatively correlated with 25(OH)D levels in both female and male T2DM patients(r=-0.996 and-0.876,respectively;both P<0.01).RCS analysis showed that HGI was associated with 25(OH)D level in T2DM patients(P<0.01),and the OR value of HGI and 25(OH)D level showed an N-shaped non-linear relationship(P<0.01,P-non-linear=0.0016);Conclusions HGI is negatively correlated with VD levels in T2DM patients.After stratification by gender,the negative correlation persists.The negative correlation between HGI and VD levels in T2DM patients has a threshold effect.When HGI is greater than-0.29,T2DM patients are more likely to have VD deficiency.
Keywords：hemoglobin A1c variability indexvitamin Dtype 2 diabetes mellitus
Publication Date：2025-07-25
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 66-71 )