Vitamin D Status and Prevalent Early Age-Related Macular Degeneration in African Americans and Caucasians: The Atherosclerosis Risk in Communities (ARIC) Study.

Julie Mares // Kleins Lab // Publications // Jan 01 2017

PubMed ID: 28717807

Author(s): Millen AE, Nie J, Sahli MW, Mares JA, Meyers KJ, Klein BEK, LaMonte MJ, Lutsey PL, Andrews CA, Klein R. Vitamin D status and prevalent early age-related macular degeneration in African Americans and Caucasians: the Atherosclerosis Risk in Communities (ARIC) Study. J Nutr Health Aging. 2017;21(7):772-780. doi: 10.1007/s12603-016-0827-6. PMID 28717807

Journal: The Journal Of Nutrition, Health & Aging, Volume 21, Issue 7, 2017

OBJECTIVES Vitamin D status has been hypothesized to protect against development of early age-related macular degeneration (AMD) via its anti-inflammatory properties and its possible beneficial influence on blood pressure control. We investigated the association between vitamin D status and prevalent early AMD in a community-based cohort.

DESIGN This was a cross-sectional study.

SETTING This was a secondary data analysis of already existing data from the Atherosclerosis Risk in Communities Study (ARIC) cohort collected from 1990 to 1995.

PARTICIPANTS There were 9,734 (7,779 Caucasians, 1,955 African American) ARIC participants (aged 46 to 70 at visit 2 [1990-1992]) with 25(OH)D data available at visit 2, AMD assessment at visit 3 (1993-1995), and complete covariate data.

MEASUREMENTS Vitamin D status was assessed with serum 25-hydroxyvitamin D (25(OH)D) concentrations from bloods drawn at visit 2. Prevalent, early AMD (n=511) was assessed at visit 3 (1993-95) with nonmydriatic retinal photographs of one randomly chosen eye. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for early AMD by categories of 25(OH)D in nmol/L (deficient <30, inadequate 30-<50, and two categories of adequate status: 50-<75 and ≥75). Linear trend was estimated using continuous 25(OH)D concentrations. ORs were adjusted for age, race, and smoking status. We further adjusted for hypertension status to examine if vitamin D status influenced early AMD via its effects on blood pressure. Exploratory analyses of effect modification by age, sex, race and high risk genotypes [Y402H complement factor H (CFH) rs1061170 and the A69S age-related maculopathy susceptibility 2 (ARMS2) rs10490924 polymorphisms] were conducted.

RESULTS The prevalence of early AMD was 5%, and 5% of participants were vitamin D deficient. The adjusted OR (95% CIs) for early AMD among those with adequate (≥75 nmol/L) compared to deficient (<30 nmol/L) vitamin D status was 0.94 (0.59-1.50), p-trend=0.86. Further adjustment for hypertension status did not influence results (OR [95% CI]=0.95 [0.59-1.52], p-trend=0.84). Results did not vary significantly by age, race, sex, early AMD subtype (soft drusen or retinal pigment epithelium depigmentation), or ARMS2 genotype. Results did not vary significantly by CFH genotype in African Americans. The p for multiplicative interaction between 25(OH)D and CFH genotype was 0.06 in Caucasians, but OR [95% CIs] for AMD by vitamin D status were similar in each CFH genotype and not statistically significant.

CONCLUSIONS Vitamin D status was not associated with early AMD in this cohort sample.