The Association Of Dietary Calcium,Magnesium,Zinc And Copper Intake With Diabetes Retinopathy

Objective:Diabetes is an important global public health problem,diabetic retinopathy（DR）is an important chronic non-communicable disease of the eye caused by abnormal glucose metabolism in diabetic patients,leading to loss of vision or blindness.Calcium,magnesium,zinc and copper,as micronutrients essential for the maintenance of basic body functions,play an important role in participating in cellular metabolic activities and oxidative stress.At present,the association of dietary calcium,magnesium,zinc,and copper with diabetic retinopathy has been little studied and controversial in home and abroad.Therefore,this study was conducted to investigate the association of dietary calcium,magnesium,zinc,and copper intake with diabetic retinopathy using the National Health and Nutrition Examination Survey（NHANES）database to provide a new theoretical basis for the prevention and treatment of diabetic retinopathy and to enhance the identification and health intervention of diabetic risk groups.Methods:This study was based on the NHANES database from 2007-2018 and selected from the diabetic population aged≥40 years,and 3794 study subjects were finally identified after inclusion and exclusion criteria.24-hour dietary review method was used to determine calcium,magnesium,zinc and copper intake.The definition of diabetic retinopathy was determined based on the relevant questionnaire.Statistical analyses were performed under complex weighting,and categorical variables were described by frequency and weighted percentage and analyzed by the Rao-Scott-χ² test;continuous normal variables were described by means±standard error and analyzed by t-test;logistic regression models were used to explore the association of dietary calcium,magnesium,zinc and copper intake with diabetic retinopathy;the relationships were stratified by gender（men,women）and age（40-64 years,65-79 years,≥80 years）to explore the effects of gender and age on the relationship between dietary intake and diabetic retinopathy;a restricted cubic spline model was used to further explore the dose-response relationship between dietary intake and diabetic retinopathy.Results:1.A total of 3794 study subjects were included in this study,including a total of791 DR,accounting for 20.85%.There were statistical differences in education level,marital status,household income,duration of diabetes,glycemic control,hypertension,use of insulin and use of diabetic drug between the diabetic retinopathy population and non-diabetic retinopathy population.No statistical differences were found in sex,age,race,BMI and smoking.2.Logistic regression analysis showed that after fully adjusting for confounders,calcium and copper Q4 groups were associated with a reduced risk of DR compared with their Q1 groups,with OR and 95%CI of 0.57（0.38-0.86）and 0.48（0.30-0.77）,respectively,and P for trend were 0.032 and 0.025,respectively;for magnesium and zinc intake,the OR and 95%CI for the risk of disease in the Q3 and Q4 groups for magnesium and zinc compared with their Q1 group were 0.62（0.43-0.92）and 0.48（0.32-0.73）,0.66（0.44-0.99）and 0.58（0.39-0.88）,respectively,with P for trend of0.008 and 0.044,respectively.3.Stratified analysis by gender showed a statistically significant association between higher magnesium and copper intake and DR in different genders;there were gender differences in the associations between calcium and zinc and DR,with higher calcium and zinc intakes associated with a lower risk of DR in men,but no statistical association was found in women.In men,for calcium intake,the OR and 95%CI for the calcium Q4 group was 0.43（0.25-0.74）compared to the calcium Q1 group;for zinc intake,the OR and 95%CI were 0.44（0.26-0.76）and 0.49（0.29-0.83）for the zinc Q3and Q4 groups,respectively,compared with the zinc Q1 group.4.The results of the age-stratified analysis showed that there were age differences in the associations between dietary calcium,magnesium,zinc,and copper intake and DR.In the 40-64 years age group,higher dietary calcium,magnesium,zinc and copper all reduced the risk of DR.For calcium intake,the OR and 95%CI for the calcium Q4group was 0.42（0.24-0.76）compared with the calcium Q1 group.For magnesium,zinc,and copper intake,compared to their Q1 groups,the OR and 95%CI for the three Q3and Q4 groups were 0.50（0.27-0.89）and 0.42（0.23-0.79）,0.52（0.30-0.90）and 0.48（0.26-0.90）,0.51（0.29-0.88）and 0.35（0.18-0.71）,respectively;in the 65-79 years age group,only a statistical association was found between magnesium intake and DR,with an OR and 95%CI of 0.50（0.26-0.96）in the magnesium Q4 group compared to the magnesium Q1 group;in the age group≥80 years old,no statistical association was found between any micronutrient and DR.5.Using the recommended dietary nutrient allowance（RDA）as a criterion,after fully adjusting for confounding factors,higher than RDA of calcium,magnesium and zinc could significantly reduce the risk of DR compared with lower RDA group.The OR and 95%CI were 0.63（0.47-0.84）,0.54（0.39-0.76）and 0.71（0.52-0.99）,respectively.6.The results of restricted cubic spline model showed that dietary calcium and copper intake had a linear dose-response relationship with the risk of DR.(P_non-linear=0.439,P_non-linear=0.132),and dietary magnesium and zinc intake had a nonlinear dose-response relationship with the risk of DR.(P_non-linear=0.041,P_non-linear=0.012).Conclusions:1.Higher dietary calcium,magnesium,zinc and copper intake may reduce the risk of retinopathy in diabetic patients over 40 years old in USA.2.In the gender-stratified analysis,higher dietary magnesium and copper intakes were negatively associated with DR in different genders.The associations between dietary calcium and zinc and DR differed by gender,and higher dietary calcium and zinc intakes may be associated with a lower risk of DR in men,but no association was found in women.3.In the age-stratification analysis,there were age differences between dietary calcium,magnesium,zinc and copper intake and DR;higher dietary calcium,zinc and copper may reduce the risk of DR in the 40-64 age group,and higher dietary magnesium may reduce the risk of DR in the 40-64 and 65-79 age groups;no association was found between dietary calcium,magnesium,zinc and copper and DR in the age group of≥80years.4.Using the RDA as a criterion,dietary calcium,magnesium and zinc intake up to RDA may be associated with a reduced risk of DR.5.A linear dose-response relationship was found between dietary calcium,copper intake and DR risk,and a non-linear dose-response relationship was found between dietary magnesium,zinc intake and DR risk.