Correlation Between Serum Bilirubin And Osteoporosis In Aged Patients With Type 2 Diabetes Mellitus

Objective By studying the correlation between serum bilirubin and osteoporosis(OP)in aged patients with type 2 diabetes mellitus,in order to explore whether serum bilirubin affects the occurrence and development of osteoporosis.Methods A retrospective investigation was conducted on 537 aged patients with type 2 diabetes mellitus who were hospitalized in the Endocrinology Department,the First Affiliated Hospital of Fujian Medical University from January 2020 to December 2020.According to the diagnostic criteria for osteoporosis of WHO,bone mineral density status was divided into normal bone mass group(T≥-1),osteopenia group(-1<T<-2.5)and osteoporosis group(T≤-2.5)according to T level,and these patients above were divided into 3 groups: normal bone mass group(n=228),osteopenia group(n=211)and osteoporosis group(n=98).Collect general data of subjects and biochemical indexes such as fasting plasma glucose(FPG),glycated hemoglobin Alc(Hb Alc),total bilirubin(TBIL),direct bilirubin(DBIL),indirect bilirubin(IBIL),alkaline phosphatase(ALP)、 serum creatinine(SCr),urea nitrogen(BUN),uric acid(UA),triglycerides(TG)and other blood lipid indicators.Calculate body mass index(BMI)and estimated glomerular filtration rate(e GFR).One-way analysis of variance,K-W test,and Chi-square test were used to compare baseline levels between groups,and the influencing factors of proteinuria staging were explored by bivariate correlation analysis and ordinal logistic regression analysis.The receiver operating characteristic curve(ROC)was used to evaluate the predictive value of serum bilirubin for osteoporosis.Results 1.TBIL values showed a decreasing trend among normal bone mass,reduced bone mass and osteoporosis groups(12.4 VS 9.8 VS 8.1,P<0.05).Compared with the normal bone mass group,the female,the age,ALP,HDL-C,special B-collagen sequence,TP1 NP and N-terminal osteocalcin were higher in the osteoporosis group(P<0.05),while the weight,height,BMI,TBIL,DBIL,IBIL,UA,vitamin D were lower.(P<0.05).Compared with the osteopenia group,the osteoporosis group was older and has shorter height,lighter weight,smaller BMI,TBIL,DBIL,IBIL,UA(P<0.05).Compared with the normal bone mass group,the osteopenia group had higher age,ALP,specific B-collagen sequence,TP1 NP,and N-terminal-osteocalcin(P<0.05),the height,weight,BMI and TBIL were lower(P<0.05).2.The patients were divided into four groups according to the quartile of total bilirubin,P<25% group,p25%-50% group,p50%-75% group,and P>75% group.With the decrease of the total bilirubin level,the detection rates of OP of p>75% group,p50%-75% group,p25%-50% group,and p<25% group all increased gradually(P<0.001).3.The liner correlation tests were performed,the results showed as followed: among the aged patients with T2 DM,there were significant positive correlations between BMD of left hip joint,femoral neck,lumbar spine L1-L4 and TBIL,IBIL,height,weight,BMI.The correlation coefficient between these parameters and BMD of lumbar spine L1-L4 were 0.199,0.087,0.524,0.422,0.194,0.151,respectively(P<0.05).The correlation coefficient between these parameters and BMD of the left hip joint were 0.277,0.169,0.415,0.436,0.235,0.198,respectively(P<0.001).The correlation coefficient between these parameters and BMD of the left femoral neck were 0.279,0.157,0.477,0.399,0.137,0.196,respectively(P<0.001).There were significant negative correlations between BMD of left hip joint,femoral neck,lumbar spine L1-L4 and age,specific B-collagen sequence,TP1 NP and HDL-C.The correlation coefficient between these parameters and BMD of lumbar spine L1-L4 were-0.201,-0.259,-0.207,-0.148,respectively(P<0.001).The correlation coefficient between these parameters and BMD of the left hip joint were-0.274,-0.222,-0.168,-0.088,respectively(P < 0.05).The correlation coefficient between these parameters and BMD of the left femoral neck were-0.344,-0.157,-0.139,-0.104,respectively(P<0.05).There were no significant correlations between BMD of left hip joint,femoral neck,lumbar spine L1-L4 and DBIL.4.Multivariate logistic regression analysis suggests that after adjusting for age,gender,ALP,BMI,HDL-C,UA,height,weight,BMI,IBIL and other confounding factors,the total bilirubin level was independently and negatively correlated with the occurrence of the osteoporosis.(OR = 0.894,P = 0.007).5.Receiver operating characteristic curve(ROC)of total bilirubin predicting OP revealed that the area under curve(AUC)was 0.671.The best predict boundary value for total bilirubin is 8.25μmol/L(sensitivity was 75.6%,and specificity was 52%).Conclusions Total bilirubin level is independently and negatively correlated with OP in aged type 2 diabetes.Total bilirubin level has certain predictive significance for OP and best predict boundary value for total bilirubin is 8.25μmol/L.