Plasma omega3 fatty acids and the risk for age-related macular degeneration: the Alienor Study

Abstract

 

Purpose:

 

High dietary intake of omega3 polyunsaturated fatty acids (PUFA) and fish have been consistently associated with a decreased risk for age-related macular degeneration (AMD). We report the associations of late AMD with plasma concentrations of omega3 PUFA, which represent a more objective assessment of omega3 PUFA status.

 

Methods:

 

The Alienor study is a prospective population-based study on nutrition and age-related eye diseases, performed in 963 residents of Bordeaux (France), aged 73 years or more. Participants are re-examined every two years since baseline (2006-2008). Plasma fatty acids were measured by gas chromatography, from fasting blood samples collected in 1999-2001. Late AMD (geographic atrophy and/or neovascular AMD) was graded from non mydriatic colour retinal photographs taken in 2006-2008 (baseline), and 2009-2011 (first follow-up). Associations of late AMD with plasma omega3 PUFA were estimated using Generalized Estimating Equation logistic regressions, after adjustment for potential confounders (age, gender, smoking, education, physical activity, plasma HDL-cholesterol, plasma triglycerides, fruits consumption, CFH Y402H, apoE4 and ARMS2 A69S polymorphisms and follow-up time). Of 963 subjects, 84 (8.7%) had no gradable photographs, 167 (17.3%) had missing data for plasma fatty acids and 107 (11.1%) for confounders, leaving 605 subjects (1170 gradable eyes) for the statistical analysis, including 96 eyes with prevalent (58) and incident (38) late AMD.

 

Results:

 

After multivariate adjustment, higher plasma total omega3 PUFA was associated with reduced risk for prevalent late AMD with borderline significance (OR=0.69 for 1-standard deviation increase, 95% confidence interval (CI): 0.46-1.04, p=0.08) and significantly with incident late AMD (OR=0.51, 95% CI: 0.28-0.92, p=0.02). When combining prevalent and incident cases, the association was highly significant (OR=0.62, 95% CI: 0.43-0.88, p=0.008). Associations were similar for plasma alpha-linolenic acid (for combined cases OR=0.62, 95% CI: 0.43-0.88, p=0.008) and long-chain omega3 PUFA (for combined cases OR=0.65, 95% CI: 0.46-0.92, p=0.01).

 

Conclusions:

 

This study shows an inverse association of late AMD with plasma omega3 PUFA, consistent with previous observations concerning dietary intakes.

 

Keywords: age-related macular degeneration • nutritional factors • clinical (human) or epidemiologic studies: risk factor assessment