Vitamin D Deficiency Is Significantly Associated with Retinopathy in Type 2 Diabetes Mellitus: A Case-Control Study

Abstract

Aim: Results from meta-analyses point to an association between vitamin D deficiency and the onset of diabetic retinopathy (DR). The objectives of the present study were to evaluate the association of vitamin D for the development of DR and to determine the levels of vitamin D associated with a greater risk of DR. Methods: Between November 2013 and February 2015, we performed a case-control study based on a sample of patients with diabetes in Spain. The study population comprised all patients who had at least one evaluable electroretinogram and recorded levels of 25(OH)D. We collected a series of analytical data: 25(OH)D, 1,25(OH)2D, iPTH, calcium, albumin, and HbA1c. Glycemic control was evaluated on the basis of the mean HbA1c values for the period 2009–2014. A logistic regression analysis was performed to identify the variables associated with DR. Results: The final study sample comprised 385 patients, of which 30 (7.8%) had DR. Significant differences were found between patients with and without DR for age (69.54 vs. 73.43), HbA1c (6.68% vs. 7.29%), years since diagnosis of diabetes (10.9 vs. 14.17), level of 25(OH)D (20.80 vs. 15.50 ng/mL), level of 1,25(OH)2D (35.0 vs. 24.5 pg/mL), treatment with insulin (14.9% vs. 56.7%), hypertension (77.7% vs. 100%), cardiovascular events (33.2% vs. 53.3%), and kidney failure (22.0% vs. 43.3%). In the multivariate analysis, the factors identified as independent risk factors for DR were treatment of diabetes (p = 0.001) and 25(OH)D (p = 0.025). The high risk of DR in patients receiving insulin (OR 17.01) was also noteworthy. Conclusions: Levels of 25(OH)D and treatment of diabetes were significantly associated with DR after adjusting for other risk factors. Combined levels of 25(OH)D < 16 ng/mL and levels of 1,25(OH)2D < 29 pg/mL are the variables that best predict the risk of having DR with respect to vitamin D deficiency. The risk factor with the strongest association was the treatment of type 2 diabetes mellitus. This was particularly true for patients receiving insulin, who had a greater risk of DR than those receiving insulin analogues. However, further studies are necessary before a causal relationship can be established.

Reduced vitamin D levels in diabetic retinopathy: cause or effect?

“…With a large base of diabetes worldwide and DR as a common complication of diabetes, it is crucial to prevent DR and nd its risk factors. The studies concluded that the development of DR was not caused by high blood glucose unilateral factors [15,16], which was consistent with our ndings that HbA1c was associated with DR. We also further con rmed a signi cant reduction in vitamin D in DR, consistent with the ndings of Castillo-Oti JM et al [17], who suggested that vitamin D de ciency was associated with DR. The results of vitamin D assays can be interfered with by various factors.…”

The Roles of Vitamins in Diabetic Retinopathy: A Narrative Review

“…Some studies have shown that the prevalence of VDD is higher in patients with type 2 diabetes than in healthy controls [ 41 , 42 , 43 ]. The results from many studies showed that patients with DR had significantly lower serum vitamin D levels compared with patients with DM without DR [ 32 , 44 , 45 , 46 , 47 , 48 , 49 ]. In addition, VDD was found to be associated with a higher prevalence of complications in patients with diabetes, such as neuropathy, nephropathy, and retinopathy [ 43 , 50 ].…”

Peran Vitamin D dalam Retinopati Diabetik

“…Berbagai studi dan metaanalisis menunjukkan hubungan antara defisiensi vitamin D dan peningkatan kejadian RD. 7,8 Vitamin D merupakan mikronutrien esensial yang sebenarnya adalah hormon steroid yang diproduksi di kulit setelah terpapar sinar matahari dalam bentuk cholecalciferol. Vitamin D terdiri dari campuran vitamin D2 (ergocalciferol) dan D3 (cholecalciferol), yang merupakan bentuk paling efektif untuk tujuan terapeutik.…”

“…Berdasarkan hasil pencarian yang dilakukan, didapatkan dari 5 penelitian menunjukkan bahwa, pasien dengan RD memiliki kadar vitamin D serum yang lebih rendah dibandingkan dengan pasien DM tanpa retinopati diabetik. 7,8,11,13 Pada penelitian Xianglong et al (2016), yang melibatkan 51 pasien DM tipe 2 dengan RD derajat yang berbeda dan 24 pasien sehat, didapatkan hasil Serum level 1,25(OH)2D3 secara signifikan berkurang pada pasien RDP. Kadar IFN-𝛾, TNF-a, IL-6, dan IL-17A secara signifikan meningkat pada pasien RDP diakrenakan aktivasi PBMC.…”