Abstract
Purpose: :
Although research suggests that Stain use may be beneficial for retinal health, a mechanism for this protective effect is still not clear. Statins are noted for their lipid lowering properties. Lutein and zeaxanthin are transported to the retina on serum lipid fractions. Consequently, altering serum lipid concentrations may influence macular pigment (MP) levels. The current investigation was designed to test this hypothesis.
Methods: :
Study 1. Serum lipid concentrations were assessed via the Cholestech LDX lipid analyzer in 20 Statin users and 20 non–users, matched for iris color, age, sex, body mass index (BMI), smoking status and dietary intake of carotenoids. A spatial profile for MP optical density (MPOD) was assessed using HFP in Newtonian view according to the CAREDS protocol. Carotenoid intake was assessed via the 7–item Eating Habits Screener© from the Block Dietary Data Systems. Study 2. One subject experienced in HFP methodology was administered a low dose (10 mg) of atorvastatin for one month. MPOD was assessed five times at baseline, four times during the intervention, and four times after cessation of Statin use. Lipid profiles were obtained prior to each MP measurement via the LDX.
Results: :
Study 1. The two groups were nearly identical on matching criteria. Total cholesterol and LDL cholesterol levels differed significantly between Statin users and non–users (p ≤ 0.001), but average MPOD did not differ between the two groups. For the Statin users, however, duration of use was inversely related to MP density for all locations tested (i.e., longer use was related to lower MP density). Study 2. MPOD was significantly lower at 3–degrees of eccentricity during the intervention (0.07) than at baseline (0.17) or at post–test (0.17). Serum total cholesterol levels and LDL levels decreased significantly during the intervention and remained low during the post–test interval (p ≤ 0.05). No other lipid fractions changed significantly as a result of the intervention.
Conclusions: :
Our past data suggest that MP density is not related to lipid profiles. However, these preliminary results suggest that altering serum lipid concentrations via Statins may influence MP density if used long–term. The intervention data from one, well–practiced, subject suggests that small decreases in MP density can be detected in the peripheral retina after one month of Statin use. Consequently, the possibility that small decreases in MP density in the short–term can aggregate with long–term Statin use (suggested by these pilot data) should be confirmed in a larger sample.
Keywords: macular pigment • lipids • antioxidants