The respective relationships between lipoprotein profile, macular pigment optical density, and serum concentrations of lutein and zeaxanthin.Invest Ophthalmol Vis Sci. 2010 Nov; 51(11):5897-905.IO
The dietary carotenoids lutein (L) and zeaxanthin (Z) are transported on lipoproteins in the serum. The mechanism of delivery of L and Z to the macula, where they constitute macular pigment (MP), is poorly understood. This study was an investigation of the respective relationships between serum lipoprotein profile, MP optical density (MPOD), and serum L and Z.
Three hundred two healthy subjects were recruited; 211 (69.9%) were women. Demographic and health details were recorded. Fasting blood samples were taken for lipoprotein analysis by spectrophotometric assay and L and Z analysis by high-performance liquid chromatography. MPOD was measured by heterochromatic flicker photometry.
The mean ± SD (range) age of all subjects was 48 ± 11 (21-66) years. There was a statistically significant and positive association between serum L concentration and both serum cholesterol concentration (r = 0.239, P < 0.001) and serum HDL concentration (r = 0.324, P < 0.001), but not with serum LDL concentration (r = 0.095, P = 0.101). There was a statistically significant but inverse association between serum triglyceride concentration and total MPOD (r = -0.118, P = 0.044). There was no significant association between MPOD and serum cholesterol concentration or serum HDL concentration (P > 0.05).
The findings are consistent with the hypothesis that HDL is important for the transport of L in serum. The mechanism(s) whereby L and Z are captured by the macula and whether the serum (apo)lipoprotein profile is important in the transfer of the carotenoids from serum to retina merit further study.