Association Of Retinopathy And Bone Metabolism In Elderly Patients With Type 2 Diabetes Mellitus

Objective:To investigate the correlation between Diabetic retinopathy（DR）and bone metabolism（BMD and general biochemical indicators of bone metabolism）in patients with T2DM and their age 60 years or older.Methods:1.Case selection:A total of 716 patients（age≥60 years old）with T2DM from the Department of Endocrinology of the Affiliated Hospital of Qingdao University from January 2016 to June 2020 were include,including 317 women and 345 men.The bone mineral density（BMD）of hip,femoral area and lumbar spine（L1-L4）were measured by dual-energy X-ray absorptiometry.According to the results of BMD,patients were divided into normal bone mass group and low bone mass group（osteopenia and osteoporosis）.The fundus condition were evaluated by the ophthalmologist to conduct fundus examination after dilated pupil.According to the examination results,the patients’were divided into NDR group and retinopathy groups（including NPDR group and PDR group）.Then the relevant factors are analyzed statistically.Results:1.The comparison of biochemical and general information among PDR group,NPDR group and NDR group of elderly patients with type 2 diabetes,showed that there were significant differences in age,menopausal age,systolic blood pressure,course of disease,fasting C-peptide,microalbuminuria,serum creatinine and estradiol in female group（P<0.05）;there were significant differences in Hb A1c,age,course of disease,systolic blood pressure,microalbuminuria,waist circumference,cholesterol,fasting C-peptide and estradiol in male group（P<0.05）.2.Comparison of BMD and general biochemical indexes of bone metabolism among PDR group,NPDR group and NDR group of elderly patients with type 2 diabetes,there were statistically significant differences in BMD of the L2,L1-L4,the femoral neck,Ward triangle,femoral trochanter and the total hip in the female group（P<0.05）;there were statistically significant differences in BMD of the lumbar spine（L1-L4）,the femoral neck,femoral trochanter and the total hip in the male group（P<0.05）.Comparison of general biochemical indexes of bone metabolism among the three groups,there were statistically significant differences in 1,25（OH）₂D₃,alkaline phosphatase and blood phosphorus in the elderly female group（P<0.05）;there were statistically significant differences in 1,25（OH）₂D₃in the elderly male group（P<0.05）.3.There were statistically significant differences in age,menopausal age,body mass index,Hb A1c,low density lipoprotein,creatinine,estradiol,uric acid and 1,25（OH）₂D₃between low bone mass group and normal bone mass group in elderly female patients with T2DM（P<0.05）.There were statistially significant differences in age,body mass index（BMI）,1,25（OH）₂D_3,osteocalcin and phosphorus between low bone mass group and normal bone mass group in elderly male patients with T2DM（P<0.05）.4.Correlation analysis of BMD:（1）Age was negatively correlated with lumbar spine（L1-L4）,femoral neck,Ward triangle,femoral trochanteric and total hip bone mineral density（r=-0.122,-0.350,-0.280,-0.290,-0.350,P<0.05）;BMI was positively correlated with with lumbar spine（L1-L4）,femoral neck,Ward triangle,femoral trochanteric and total hip bone mineral density（r=0.234,0.133,0.118,0.199,0.188,P<0.05）;the age of menopause was positively correlated with femoral neck,Ward triangle,femoral trochanter and total hip bone density（r=0.114,0.155,0.108,0.135,P<0.05）in elderly female patients with type 2 diabetes mellitus.（2）Age was negatively correlated with Ward’s triangle BMD（r=-0.01,P<0.05）;BMI was positively correlated with lumbar spine（L1-L4）,femoral neck and total hip bone density（r=0.198,0.131,0.122,P<0.05）in elderly male patients with type 2 diabetes mellitus.5.When elderly female patients with type 2 diabetes have DR,the incidence of low bone mass was high,and as the severity of DR increased,the prevalence of low bone mass gradually increased,and the difference was statistically significant（25.8%vs 39.5%vs 48.3%,χ2=9.956,P=0.007）.When elderly male patients with type 2 diabetes have DR,the incidence of low bone mass was high,and as the severity of DR increased,the prevalence of low bone mass gradually increased,and the difference was statistically significant（17.3%vs 38.1%vs 43.3%,χ2=11.647,P=0.003）..6.The presence of low bone mass as a dependent variable was used for binary logistic regression analysis.The results indicate that DR and advanced age were independent risk factors for the occerrence of low bone mass in the elderly patients with T2DM,,and that low bone mass in patients with retinopathy was 5.018 times higher than that in patients without retinopathy（OR=3.481,P=0.000）.Conclusion:1.Diabetic retinopathy is closely related to bone loss in elderly patients with type 2diabetes mellitus of different genders.2.The incidence of bone loss increased with the severity of diabetic retinopathy progression in both male and female elderly patients with type 2 diabetes;3.In elderly patients with type 2 diabetes mellitus complicated with diabetic retinopathy is a risk factor for the occurrence of low bone mass,and diabetic microvascular lesions may be a promoting factor for bone loss.Vascular changes can cause chronic bone ischemia,resulting in changes in in the function and number of osteoblasts,and ultimately lead to reduced bone formation,low bone mass,and increased fracture risk.