Original ArticleVitamin D Insufficiency in Diabetic Retinopathy
Section snippets
INTRODUCTION
Diabetes mellitus continues to be a tremendous health burden in the United States. In 2007, diabetes was estimated to involve 23.6 million people, or 7.8% of the population (1). The number of people diagnosed with diabetes is expected to increase to 48.3 million by the year 2050 (2). Diabetes is also the leading cause of new blindness in patients 20 to 74 years of age (1). Although it has been well established that intensive blood glucose control can lower the risk of microvascular
PATIENTS AND METHODS
The Emory University (Atlanta, Georgia) School of Medicine Institutional Review Board approved this study, and all work was conducted in accordance with the Health Insurance Portability and Accountability Act regulations. This research followed the tenets of the Declaration of Helsinki. A clinic-based cross-sectional study was designed at the Emory Eye Center.
Study Subject Characteristics
Results of the univariate analysis across the study groups are shown in Table 1. There was no statistically significant difference between the study groups with regard to age, race, sex, or multivitamin use. There was, however, a statistically significant difference in the study groups with regard to BMI (P = .003), A1C (P < .001), hypertension (P < .001), and macrovascular disease (P = .002). Among those patients with diabetes, there was also a statistically significant difference in the duration
DISCUSSION
There were 2 purposes of this cross-sectional study. The first was to assess the relationship between vitamin D status and diabetic retinopathy, and the second was to establish baseline data from which a larger prospective clinical study could be designed. It was found that patients with type 2 diabetes, particularly those with PDR, had lower vitamin D levels than did those without diabetes. Moreover, there was a higher percentage of study subjects with vitamin D insufficiency in the diabetic
CONCLUSION
This study showed that patients with type 2 diabetes mellitus, especially those with PDR, had lower 25(OH)D levels and were more likely to have vitamin D insufficiency than were patients without diabetes. The use of multivitamins was also somewhat protective against vitamin D insufficiency. Although this is the largest study to date designed to assess this relationship, larger studies are needed to confirm these findings. In addition, studies are needed to assess whether the treatment of
DISCLOSURE
The authors have no multiplicity of interest to disclose.
ACKNOWLEDGMENT
This study was supported in part by a grant to Emory University Eye Center from Research to Prevent Blindness, Inc., and through a departmental grant from the National Eye Institute of the National Institutes of Health (EY06360). The sponsors had no role in the design or conduct of this research.
REFERENCES (29)
Vitamin D: importance in the prevention of cancers, type 1 diabetes, heart disease, and osteoporosis [published correction appears in Am J Clin Nutr. 200479:890]
Am J Clin Nutr
(2004)- et al.
Vitamin D deficiency and risk for cardiovascular disease
Am J Med Sci
(2009) - et al.
Estimation of optimal serum concentrations of 25-hydroxyvitamin D for multiple health outcomes [published corrections appear in Am J Clin Nutr. 200684:1253 and Am J Clin Nutr. 200786:809]
Am J Clin Nutr
(2006) - et al.
Evaluation of vitamin D repletion regimens to correct vitamin D status in adults
Endocr Pract
(2009) - et al.
Intravitreous vascular endothelial growth factor and hypoxia-inducible factor 1a in patients with proliferative diabetic retinopathy
Am J Ophthalmol
(2009) - et al.
Hypovitaminosis D is associated with insulin resistance and beta cell dysfunction
Am J Clin Nutr
(2004) - et al.
Optimal vitamin D status attenuates the age-associated increase in systolic blood pressure in white Americans: results from the third National Health and Nutrition Examination Survey
Am J Clin Nutr
(2008) - et al.
Serum 1,25 dihydroxy vitamin D (1,25(OH)2D3), 25 hydroxy vitamin D (25(OH)D) and parathormone levels in diabetic retinopathy
Clin Biochem
(2000) - et al.
Human serum 25-hydroxycholecalciferol response to extended oral dosing with cholecalciferol [published correction appears in Am J Clin Nutr. 200378:1047]
Am J Clin Nutr
(2003) - Centers for Disease Control and Prevention. 2007 national diabetes fact sheet: general information and national...