The respective relationships between lipoprotein profile, macular pigment optical density, and serum concentrations of lutein and zeaxanthin.
OBJECTIVE
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.


METHODS
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.


RESULTS
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).


CONCLUSIONS
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.
Loane
Edward
E
Macular Pigment Research Group, Department of Chemical and Life Sciences, Waterford Institute of Technology, Waterford, Ireland. edwardloane@yahoo.com
Nolan
John M
JM
Beatty
Stephen
S
D000328:Adult; D000368:Aged; D002784:Cholesterol / Q000097:blood*; D008076:Cholesterol, HDL / Q000097:blood*; D008078:Cholesterol, LDL / Q000097:blood*; D002851:Chromatography, High Pressure Liquid; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D014975:Lutein / Q000097:blood*; D008297:Male; D008875:Middle Aged; D010783:Photometry; D012168:Retinal Pigments / Q000378:metabolism*; D011795:Surveys and Questionnaires; D014280:Triglycerides / Q000097:blood*; D024341:Xanthophylls / Q000097:blood*; D055815:Young Adult; D065146:Zeaxanthins
D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D012168:Retinal Pigments; D014280:Triglycerides; D024341:Xanthophylls; D065146:Zeaxanthins; D002784:Cholesterol; D014975:Lutein