Glycated hemoglobin A1C and vitamin D and their association with diabetic retinopathy severity

M Long,D Liu,C Wang

doi:10.1038/nutd.2017.30

Abstract

Objectives:This retrospective, population-based, cross-sectional study evaluated the association between vitamin D deficiency and retinopathy severity in diabetic patients with poorly or well controlled glycaemia. Other potential risk factors for diabetic retinopathy severity were also assessed.Methods:The National Health and Nutrition Examination Survey (NHANES) 2005–2008 data were used for the study. Outcomes assessed included retinopathy severity, HbA1c levels, socioeconomic, behavioral, and biological factors. Univariate and multivariate regression analysis was used to evaluate association of different parameters with retinopathy severity. The interaction among HbA1c control, vitamin D deficiency, and retinopathy severity were also explored.Results:The population included 842 adults (52.8% women) with mean age of 61.2 years. Retinopathy was detected in 301 subjects (35.7%). Mild non-proliferative retinopathy (NPR) was present in 195 subjects (23.2%), severe non-proliferative and proliferative retinopathy in 106 subjects (12.6%). Multivariate ordinal regression analysis found being male (odds ratio (OR): 1.602, P=0.001), increased duration of diabetes (OR: 1.072, P=3.77E−7) and poorly controlled HbA1c (OR: 3.522, P=2.00E−5) were associated with greater retinopathy severity. The association between vitamin D deficiency and retinopathy severity only found in diabetic patients with well controlled glycaemia.Conclusions:The findings of this study indicate that vitamin D deficiency associated with severe diabetic retinopathy in patients with well controlled diabetes. The findings provide possible relationship for the previous conflict results, and highlight the need for controlling modifiable risk factors to reduce the development of sever diabetic retinopathy.

Highlights

Diabetic retinopathy is the most common complication of diabetes and is the leading cause of blindness in persons aged 20 to 65 years.[1,2] Data from 2005 to 2008 National Health and Nutrition Examination Survey (NHANES 2005–2008) found that the risk of diabetic retinopathy affects 28 to 30% of people with diabetes,[3] which is about 3.8% of the United States population.[4]The prevalence of diabetic retinopathy was observed to be 37% in newly detected diabetes patients and 18% when considering all diabetic cases among those aged 40 years and older.[5]Diabetic retinopathies that can result in vision loss include severe non-proliferative retinopathy (NPR), macular edema and retinal neovascularization
Subjects with severe NPR/proliferative retinopathy had the longest duration of diabetes (18.2 years, P = 1.03E − 8) followed by those with mild NPR (14.4 years) subjects with no retinopathy (7.5 years)
A higher percentage of poorly controlled HbA1C in the severe NPR/proliferative retinopathy group (71.6% compared with 65.3% for mild NPR and 33.1% for no retinopathy, P = 6.33E − 8)

Summary

Introduction

Diabetic retinopathy is the most common complication of diabetes and is the leading cause of blindness in persons aged 20 to 65 years.[1,2] Data from 2005 to 2008 National Health and Nutrition Examination Survey (NHANES 2005–2008) found that the risk of diabetic retinopathy affects 28 to 30% of people with diabetes,[3] which is about 3.8% of the United States population.[4]The prevalence of diabetic retinopathy was observed to be 37% in newly detected diabetes patients and 18% when considering all diabetic cases among those aged 40 years and older.[5]Diabetic retinopathies that can result in vision loss include severe non-proliferative retinopathy (NPR), macular edema and retinal neovascularization. The prevalence of diabetic retinopathy was observed to be 37% in newly detected diabetes patients and 18% when considering all diabetic cases among those aged 40 years and older.[5]. Several studies have investigated risk factors associated with diabetic retinopathy and identified both modifiable and non-modifiable risk factors for the presence and severity of diabetic retinopathy.[4,6,7,8,9,10] Modifiable risk factors that have been identified include the levels of blood glucose, blood pressure, serum lipids, obesity, alcohol and smoking.[7,8] Other modifiable risk factors include level of education and use of vitamin D or calcium supplements[7,8] Non-modifiable risk factors are duration of diabetes, gender and age.[7,8] Other independent variables include type of diabetes and family history of diabetic retinopathy.[9]

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Conclusion