The Diabetes Visual Function Supplement Study (DiVFuSS)

Abstract

BackgroundDiabetes is known to affect visual function before onset of retinopathy (diabetic retinopathy (DR)). Protection of visual function may signal disruption of mechanisms underlying DR.MethodsThis was a 6-month randomised, controlled clinical trial of patients with type 1 and type 2 diabetes with no retinopathy or mild to moderate non-proliferative retinopathy assigned to twice daily consumption of placebo or a novel, multi-component formula containing xanthophyll pigments, antioxidants and selected botanical extracts. Measurement of contrast sensitivity, macular pigment optical density, colour discrimination, 5-2 macular threshold perimetry, Diabetic Peripheral Neuropathy Symptoms, foveal and retinal nerve fibre layer thickness, glycohaemoglobin (HbA1c), serum lipids, 25-OH-vitamin D, tumour necrosis factor α (TNF-a) and high-sensitivity C reactive protein (hsCRP) were taken at baseline and 6 months. Outcomes were assessed by differences between and within groups at baseline and at study conclusion using meand ± SDs and t tests (p<0.05) for continuous variables.ResultsThere were no significant intergroup differences at baseline. At 6 months, subjects on active supplement compared with placebo had significantly better visual function on all measures (p values ranging from 0.008 to <0.0001), significant improvements in most serum lipids (p values ranging from 0.01 to 0.0004), hsCRP (p=0.01) and diabetic peripheral neuropathy (Fisher's exact test, p=0.0024) No significant changes in retinal thickness, HbA1c, total cholesterol or TNF-α were found between the groups.ConclusionsThis study provides strong evidence of clinically meaningful improvements in visual function, hsCRP and peripheral neuropathy in patients with diabetes, both with and without retinopathy, and without affecting glycaemic control.Trial registration numberwww.ClinicalTrials.gov Identifier: NCT01646047

Oxidative stress, mitochondrial damage and diabetic retinopathy

“…Antioxidant properties containing calcium dobesilate and A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPT 25 pycnogenol reduce the progression of diabetic retinopathy [100,101]. Our recent double masked study using a multi-component nutritional formula (vitamins C, D3, and E, zinc oxide, eicosapentoenoic acid, docosahexaenoic acid, alpha-lipoic acid, coenzyme Q10, zeaxanthin, lutein, benfotiamine, N-acetyl cysteine, resveratrol, turmeric root extract, green tea leaf) has shown encouraging results, as this multi-component nutritional formula can improve visual function and reduce serum inflammatory proteins in diabetic patient [102]. However, others have not observed any significant association between serum levels of major dietary antioxidants and retinopathy [103].…”

Lutein and Zeaxanthin Isomers in Eye Health and Disease

“…Contrast sensitivity is well correlated with various aspects of visual ability, such as orientation and mobility, reading speed, and driving (157), and with the satisfaction of individuals with their visual function and how their visual ability affects their quality of life (53). Supplements containing L and Z at various amounts and taken for three months to three years have improved contrast sensitivity in most previous studies, including in young, healthy subjects (37, 67, 94, 113, 115), in people with early (78, 116, 156) and/or advanced (12) AMD, and in individuals with diabetes (43, 77). Four of five randomized, placebo-controlled trials of solely L and/or Z isomers in >50 subjects observed improvements in spatial contrast sensitivity (77, 78, 116, 192); results of one other trial did not (135).…”

“…Results of some but not all intervention studies (1, 11, 115, 133, 135, 187, 192) indicate improvements in visual acuity when L and/or Z are supplemented alone (77, 113, 139) or, more often, in conjunction with other antioxidants and/or omega-3 fatty acids (1, 12, 43, 49, 147, 155). Three of seven randomized trials in >50 individuals with early or advanced AMD (116, 156) or with diabetic retinopathy (77) indicate improvements in visual acuity.…”

Clinical relevance of epigenetics in the onset and management of type 2 diabetes mellitus

“…The results of the study showed that the multicomponent nutritional formula ameliorates glycemic control, visual function, and peripheral neuropathy in patients with diabetes (Table 2). 85 …”