Correlation Analysis Between Time In Range And Bone Mineral Density In T2DM Patients

Purpose Patients with type 2 diabetes mellitus(T2DM)are prone to osteoporosis(OP),which may be related to the fluctuation of blood glucose.In this study,TIR was obtained from capillary blood glucose monitoring data in patients with T2DM,and the correlation between TIR and bone mineral density(BMD)was analyzed.Methods A total of 219 T2DM patients hospitalized in the Department of Geriatrics,the second Hospital of Lanzhou University from June 2021 to December2022 were selected as subjects.The basic and clinical data of all subjects were collected.Including sex,age,course of T2DM,past medical history,smoking history,drinking history,hypoglycemic regimen,height,weight,diabetic complications,HbA1C,high density lipoprotein,low density lipoprotein,triglyceride,total cholesterol,serum creatinine,urea nitrogen,uric acid,alkaline phosphatase,serum calcium,blood phosphorus,Parathyroid hormone,25 hydroxyvitamin D,calcitonin,2 hours postprandial blood glucose(2h PG),2 hours postprandial insulin(2h INS),fasting insulin(FINS),insulin resistance index(HOMA-IR).All fingertip blood glucose data recorded during the course of T2DM were collected,including at least 7 points blood glucose spectrum within 3 days before admission and the first 3 days after admission.Fingertip blood glucose monitoring data were used to calculate TIR,time above range(TAR),mean blood glucose(MBG),standard deviation of blood glucose(SDBG),largest amplitude of glycemic excursions(LAGE),postprandial glucose excursions(PPGE).The bone mineral density of ulna,radius,L1-L4 and neck was measured by dual energy X-ray absorptiometry.Using the statistical software spss26.0 to select the appropriate statistical method for data statistics and analysis.Results(1)Basic information:a total of 219 cases were selected,including 150males and 69 females,including 77 cases(33.6%)in osteoporosis group,110 cases(48.0%)in osteopenia group and 32 cases(18.3%)in normal bone mass group.There are 46,79 and 25 males in the osteoporosis group,osteopenia group and normal bone mass group,accounting for 30.67%,52.67%and 16.67%of the total number of men,and 31 cases,31 cases and 7 cases of women,accounting for 44.93%,44.93%and 10.14%of the total number of women.(2)Comparison of clinical data among osteoporosis group,osteopenia group and normal bone mass group:compared with osteoporosis group,the utilization rate of secretion enhancers,2h PG,ALP,PTH,blood P,TAR,MBG,SDBG,LAGE in osteopenia group and normal bone mass group are lower,while BMI,CT,UA,blood Ca,TZD utilization rate,SGLT2i utilization rate and TIR are higher.(3)Correlation analysis of bone mineral density with blood glucose fluctuation index and other indexes:Spearman correlation analysis showes that age,ALP,TAR,MBG,SDBG,LAGE of T2DM patients are negatively correlated with ulna,radius,L1-L4 and neck bone mineral density,while BMI,SGLT2i utilization rate,SCr,UA,CT,TIR are positively correlated with ulna,radius,L1-L4,neck bone mineral density.The utilization rate of secretion enhancer and HDL are negatively correlated with the bone mineral density of ulna,radius and L1-L4,but has no significant difference with the bone mineral density of neck(P>0.05).Taking the bone mineral density of ulna,radius,L1-L4 and neck as dependent variables,correlation analysis and previous meaningful indexes as independent variables,stepwise linear regression analysis was carried out.The results show that TIR and BMI are positive influencing factors of bone mineral density of ulna and radius,L1-L4 and neck,while female gender is a negative factor of bone mineral density of the above three parts.Age is a negative factor affecting bone mineral density of ulna,radius and L1-L4,but age has no significant effect on bone mineral density of neck,uric acid is a positive factor of bone mineral density of ulna and radius,but uric acid has no significant effect on L1-L4 and neck bone mineral density.(4)Correlation analysis of TIR with bone mineral density and osteoporosis:taking TIR level as independent variable and ulnar and radial bone mineral density,L1-L4 and neck bone mineral density as dependent variables,linear correlation analysis between TIR and bone mineral density was performed.After gradually correcting confounding factors,TIR is positively correlated with ulna,radius,L1-L4 and neck bone mineral density.Linear correlation analysis was made between TIR and bone mineral density of ulna,radius,L1-L4 and neck in male group and female group respectively.After correcting confounding factors step by step,it is found that there is a positive correlation between TIR and bone mineral density of ulna,radius,L1-L4 and neck in different gender groups.Taking the occurrence of osteoporosis as the dependent variable,TIR and previous meaningful indicators as independent variables,Logistic regression analysis was performed to gradually correct the confounding factors.It is found that TIR is negatively correlated with osteoporosis.When TIR decreases by 10%,the risk of osteoporosis increases by 9.5%.There is a negative correlation between TIR and osteoporosis in different gender groups(P<0.05).(5)The critical value of TIR for osteoporosis in patients with T2DM:taking osteoporosis as the state variable and the test variable as TIR to draw the ROC curve,the most approximate index is 0.476,the corresponding TIR is 62.5%,the sensitivity is64.5%,the specificity is 83.1%,and the critical value of TIR for osteoporosis is 62.5%.(6)The change trend of the risk of osteoporosis in TIR substandard group and TIR standard group:according to the level of TIR,the subjects were divided into TIR substandard group(TIR≤70%)and TIR standard group(TIR>70%).The clinical data of the two groups were compared:2h PG,FINS,HbA1C,ALP,incidence of microangiopathy,insulin use rate,HOMA-IR incidence,TAR,MBG,SDBG,LAGE,PPGE,prevalence of osteoporosis in TIR substandard group are higher than those in standard group.UA,CT,ulna and radius,L1-L4,neck bone mineral density and metformin utilization rate are lower than those in the standard group.Logistic regression analysis was used to analyze whether TIR reached the standard and osteoporosis.Taking the TIR standard group as the control group,the confounding factors were corrected step by step.The results showes that when the TIR reaches the standard,the risk of osteoporosis decreases.Compared with the TIR standard group,the risk of osteoporosis increases by 4.464 times in the TIR standard group.(7)Linear regression analysis of TIR and bone mineral density in different groups:after gradually correcting the confounding factors,it is found that no matter whether the HbA1C is up to the standard,no matter whether the age is over 60 years old,no matter how long the course of T2DM is,no matter what the 25(OH)D level is.TIR is positively correlated with bone mineral density of ulna,radius,L1-L4 and neck.In BMI18.5～24 kg/m~2 group and BMI>24 kg/m~2 group,TIR is positively correlated with bone mineral density of ulna,radius,L1-L4 and neck,but there is no significant relationship between TIR and bone mineral density in BMI<18.5kg/m~2 group.(8)Correlation between HbA1C and TIR:through Spearman correlation analysis,there is a significant negative correlation between TIR and HbA1C.With TIR as independent variable and HbA1C as dependent variable,the linear regression equation of TIR and HbA1C is obtained by linear regression analysis:HbA1C=11.03-0.05TIR.Every 10%increase in TIR equals a decrease of 0.5%in HbA1C.Conclusion(1)The TIR obtained from capillary blood glucose monitoring data of patients with T2DM is positively correlated with ulna bone,radius bone,L1-L4 and neck bone mineral density.TIR is an independent influencing factor of ulnar bone,radius bone,L1-L4 and neck bone mineral density.(2)Low levels of TIR are closely related to the occurrence of osteoporosis in patients with T2DM.When the TIR level increases,the risk of osteoporosis decreases.