Calcium And Phos Phorus Metabolism And Bone Mineral Density In Children And Adolescents With Type 1 Diabetes Mellitus

BACKGROUND In recent years,the incidence of type 1 diabetes mellitus(T1DM)has increased obviously and has become an important issue that threatens the health of children and adolescents.Previous studies have shown that T1 DM can affect calcium and phosphorus metabolism and bone growth in children through a variety of mechanisms,leading to abnormal calcium and phosphorus metabolism and bone mineral density decline.The effect of blood glucose management on calcium and phosphorus metabolism and bone mineral density in T1 DM is still not studied fully,Especially,there are few studies on the effect of blood sugar management on calcium and phosphorus metabolism and bone mineral density in children and adolescents with T1 DM in China.The purpose of this study is to understand the status of calcium and phosphorus metabolism and bone mineral density in TIDM children and adolescents managed by our center for a long time,and to analyze the relationship between T1 DM blood glucose control level and abnormal calcium and phosphorus metabolism and bone mineral density decline.Thisstudyaimed tohelpto improve the abnormal calcium and phosphorus metabolism and provide evidence for reducing osteoporosis risk in TIDM children and adolescents.Methods Atotal of 78 T1 DM patients who were managed in Children’s Medical Center of the Affiliated Hospital of Qingdao University and 34 normal controls aged4-14 years were recruited from January 2016 to December 2017.Type 1 diabetes mellitus was divided into two groups according to the glycosylated hemoglobin level(whether HbA1 c is higher than 7.5%): good glycemic control group(group A)and poor glycemic control group(group B).The patients received basic data collection and medical history collection.Photoelectric colorimetry,electro chemiluminescence and high performance liquid chromatography were used to detect the Fasting blood glucose(FBG),blood calcium,blood phosphorus,alkaline phosphatase(AKP),25-hydroxy vitamin D and glycosylated hemoglobin.Bone mineral density(BMD)and T value were measured by dual-energy X-ray absorptiometry.The indexes of calcium and phosphorus metabolism and bone mineral density were compared.Results1.Changes of calcium and phosphorus metabolic indexes in patients with T1DM:Compared with control group,there were no significant differences in serum calcium(p=0.398),blood Phosphorus(P=0.606)and calcium-phosphorus product(P=0.27)between T1 DM group and control group,but alkaline phosphatase was significant higher in T1 DM group.The level of 25-hydroxyvitamin D was significantly lower than that of the control group(25.34±7.76ng/ml VS 31.85±8.94 ng/ml,P<0.001),which was higher than that of the normal control group(126.53 ± 10.31IU/LVS110.02 ± 13.19IU/L,P<0.001).There were no significant differences in serum calcium(P=0.327),phosphorus(P=0.879)and calcium-phosphorus product(P=0.342)between the two groups.Alkaline phosphatase in group A was significantly lower than that in group B(121.3 ±12.71 IU/L VS131.27 ±12.66 IU/L,P< 0.001),while25-hydroxyvitamin D in group A was significantly higher than that in group B(27.42±8.04 ng/ml VS 23.46±7.07 ng/ml,P < 0.024).2.Changes of bone mineral density in children and adolescents with T1DM: BMD in T1 DM group was significantly lower than that in control group(0.44±0.08g/cm2 VS0.58±0.10g/cm2,P < 0.01),and T value of bone mineral density in T1 DM group was also lower than that in normal control group(-0.78±0.36 VS-1.61±0.63,P < 0.01),and the proportion of bone mineral density decreased in T1 DM group was significantly higher than that in normal control group(71.8% and 20.6%,P<0.01).The BMD in group B was significantly lower than that in group A(0.41± 0.08 VS0.47± 0.07g/cm2 VS g/cm2,P<0.001).3.Relevant factors of bone mineral density change in T1 DM children and adolescents:Pearson correlation analysis showed that BMD in T1 DM children and adolescents was correlated with HbA1c(R=-0.53,P < 0.01),serum calcium(R=0.396,P < 0.01)and 25-hydroxyvitamin D(R=0.516,P < 0.01).Multivariate logistic regression analysis showed that elevated glycosylated hemoglobin(OR = 1.415,95% CI1.13-1.75),decreased 25-hydroxyvitamin D(OR = 1.114,95% CI 1.02-1.216)and increased course of disease(OR = 1.13,95% CI 1.012-1.233)were independent risk factors for bone mineral density decline in children and adolescents with T1 DM.Conclusion1.There was no significant difference in serum calcium and phosphorus between T1 DM children and healthy children,but the levels of vitamin D and bone mineral density decreased significantly,and there was a significant negative correlation with blood sugar control level.Poor blood glucose control,vitamin D deficiency and disease course increase were risk factors for bone mineral density reduction in T1 DMchildren and adolescents.2.In the future,we need to strengthen the management of blood glucose and vitamin D supplementation in children and adolescents with T1 DM,which is expected to improve the bone mineral density level of children and adolescents with T1 DM and prevent the occurrence of osteoporosis.