Association Between Glycosylated Hemoglobin A1c And Bone Biochemical Markers In Type 2 Diabetes Of Postmenopausal Women

Objective:The aim of this study was to investigate whether there was a discrepancy in the levels of bone biochemical markers between postmenopausal women with type 2 diabetes mellitus(T2DM)and healthy postmenopausal women and to explore the relationship between the level of glycosylated hemoglobin A1c(Hb A1c)and bone biochemical markers in these subjects.Methods:The selected subjects were postmenopausal women diagnosed with T2 DM who were treated in the First Affiliated Hospital of Anhui Medical University from January 2017 to June 2018,strict inclusion criteria were included,214 postmenopausal women with T2 DM were eventually enrolled in the study as an observation group,93 postmenopausal women who had physical examination in our hospital during this time period as the control group.The differences in the levels of bone biochemical markers between patients and controls were analyzed by one-way ANOVA or chi-square test.Furthermore,the relationship between Hb A1 c and bone biochemical markers was analyzed by multivariate regression,forest plot and fitted curve after adjusted different variables.Results:Bone formation markers including N-MID osteocalcin and procollagen type 1amino-terminal pro-peptide(PINP)were decreased in observation group compared tocontrols(17.66±9.75ng/m L vs 23.67±7.58ng/m L,P<0.001;48.06±27.61ng/m L vs65.86±21.06ng/m L,P<0.001,respectively),but the bone resorption markers?-cross Laps(?-CTX)was no difference between the two groups(0.57±0.29g/m L vs0.55±0.21g/m L,p=0.448).In observation group,multivariate regression showed that Hb A1 c was inversely associated with N-MID osteocalcin and PINP after adjusting for age,BMI,menopause's years,diabetic duration,history of fracture(Yes or No),diabetic complications,treatment of T2 DM,TC,TG,HDL-c,LDL-c,creatinine,UA and e GFR.The adjusted coefficients for N-MID osteocalcin and PINP per 1% Hb A1 c decrease were-0.64(-1.17,-0.11)and-1.67(-3.26,-0.08),respectively.In the unadjusted model,each 1% Hb A1 c increment was associated with a lower level of N-MID osteocalcin with a ?(95% CI)of-0.92(-1.47,-0.37),and a lower level of P1 NP with a ?(95%CI)of-1.84(-3.42,-0.26),the linar relationship was weaken after adjustment.A segmentation effect was seen in the fitted curve between Hb A1 c and ?-CTX with an inflection point at 7.4% of Hb A1 c,the highest quartile of ?-CTX(>0.74ng/m L)showed a significantly negative with Hb A1 c.No significant association was seen between Hb A1 c and biochemical markers PTNP,25(OH)D3.Conclusions:Our study found that bone formation was inhibited in postmenopausal women with T2 DM,but bone resorption was not affected,and poor glycemic control was related to lower levels of bone formation.