Cross-Sectional Study on Vitamin D, Zinc Oxide and Fatty Acid Status in a Population with a Moderate to High Risk of AMD Identified by the STARS® Questionnaire

Abstract

Introduction: A prospective study was carried out in Belgium to determine the proportion of subjects with a moderate to high risk of developing age-related macular degeneration (AMD), identified using the STARS^® (Simplified Théa AMD Risk-Assessment Scale) questionnaire, who were in need of nutritional supplementation, by assessing the vitamin D, zinc oxide and fatty acid profile status.

Methods: This multicentre cross-sectional pilot study involved 50 Belgian subjects with no or early AMD, aged > 55 years who were at moderate to high risk for AMD. Subjects were assessed using the STARS^® questionnaire, visual acuity assessment, an optical coherence tomography scan of the macula and fundus photography. Blood samples were collected, and serum analyses were performed to determine the the omega-6:omega-3 (Ω6:Ω3) ratio and the levels of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), zinc and cupric oxides and vitamin D.

Results: Abnormal serum levels for at least one of the micronutrients was detected in 94% of the subjects. Lower than optimal vitamin D levels were found in 76% of the participants, and 68% of the subjects demonstrated at least one abnormal fatty acid profile. The Ω6:Ω3 ratio was above the reference range for normal values in 54% of the subjects; DHA and EPA levels were below the reference range in 60 and 46% of the subjects, respectively; and zinc oxide concentration was below the reference range in 50% of the subjects. Only 12% of the subjects exhibited cupric oxide deficiency.

Conclusion: In this study, the STARS^® questionnaire was used for early identification of patients at moderate to high risk of AMD in real life. These patients presented a suboptimal nutritional status. Further research is needed to determine if specific diet modification or micronutrient supplement intake delays the onset or slows down the progression of AMD in these subjects.

Trial registration: Trial registration: ClinicalTrials.Gov, identifier: NCT04482465.

Keywords: AMD; Micronutrients; Omega-6/omega-3; Vitamin D; Zinc.

Fig. 1

a Number (n) and proportion (%) of subjects presenting with levels of zinc oxide, cupric oxide, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) below the range of reference values and with an omega-6:omega-3 (Ω6:Ω3) ratio above the range of reference values. Asterisk indicates interquartile range (25–75%). b Number (n) and proportion (%) of subjects presenting with vitamin D levels below the optimal range. These subjects were further analysed to identify the number and proportion of them exhibiting vitamin D insufficiency or vitamin D deficiency (36 and 40%, respectively). c Graph representation of the percentage of subjects with abnormal serum levels of micronutrients tested

Fig. 2

Subgroup analysis for vitamin D median concentration depicting a trend for certain groups. Dotted boxes (male, subjects with BMI >25, subjects with a history of hypertension, atherosclerosis and cataract surgery, subjects at high AMD risk) represent groups exhibiting a median concentration of vitamin D below the vitamin D deficiency threshold of 20 μg/L. Grey shaded boxes represent groups exhibiting a median concentration of vitamin D between deficiency (20 μg/L) and insufficiency levels (30 μg/L). Asterisk indicates that data were not available for 1 out of 50 subjects