Changes in macular pigment optical density and serum concentrations of lutein and zeaxanthin in response to weight loss.

The objective of the present study was to investigate whether weight loss is associated with changes in serum concentrations of lutein (L) and zeaxanthin (Z), and/or macular pigment optical density (MPOD). We recruited 104 overweight subjects into this randomised controlled weight loss study. For the intervention group (I group), weight was assessed weekly and body composition, including BMI (kg/m2) and body fat (kg and percentage), was assessed at baseline, 6 and 12 months. Weight loss was encouraged using dietary and exercise programmes. MPOD was measured by heterochromatic flicker photometry and serum concentrations of L and Z by HPLC (at baseline, 1, 3, 6 and 12 months). The control (C) group was assessed at baseline and 12 months. Repeated-measures ANOVA (RMA) demonstrated significant weight loss in the I group over the study period (P = 0·000). There was no significant weight change in the C group (P = 0·993). RMA of dietary L and Z, serum L and Z, and MPOD demonstrated no significant time or time × group interaction effect in any of these parameters (P>0·05 for all), with the exception of a significant decrease in the dietary intake of Z seen in both groups, over the study period (P < 0·05). There was a positive and significant relationship between body fat loss (kg) and increase in serum concentrations of L in the I group (r 0·521; P = 0·006). Our finding that a reduction in body composition (e.g. fat mass) is related to increases in serum concentrations of L is consistent with the hypothesis that body fat acts as a reservoir for this carotenoid, and that weight loss can positively influence circulating carotenoid levels.

A central dip in the macular pigment spatial profile is associated with age and smoking.

PURPOSE: To investigate the relationship between specific macular pigment (MP) spatial profiles and risk factors for age-related macular degeneration (AMD). METHODS: The MP spatial profile of 484 healthy subjects was measured with customized heterochromatic flicker photometry (cHFP) and categorized into one of two profile types: typical exponential or atypical "central dip." Data on risk factors for AMD were obtained with a general health and lifestyle questionnaire. Dietary and serum concentrations of lutein (L) and zeaxanthin (Z) were also assessed. RESULTS: The presence of the central dip MP spatial profile was significantly more common in older subjects (the mean ± SD age of subjects with a central dip MP spatial profile was 46.9 ± 12 years, whereas the mean age of subjects with a typical MP spatial profile was 41.8 ± 12 years; P = 0.004) and in current cigarette smokers (P = 0.031). Also, there was a significant age-related decline in central MP optical density (MPOD; 0.25° retinal eccentricity), but in the men only (r = -0.146, P = 0.049). CONCLUSIONS: A central dip in the MP spatial profile, seen in older subjects and in cigarette smokers, may represent an undesirable feature of macular pigmentation. Further research is needed in this area.

Foveal anatomic associations with the secondary peak and the slope of the macular pigment spatial profile.

PURPOSE: To investigate the reproducibility of the macular pigment (MP) spatial profile by using heterochromatic flicker photometry (HFP) and to relate the MP spatial profile to foveal architecture. METHODS: Sixteen healthy subjects (nine had the typical exponential MP spatial profile [group 1]; seven had a secondary peak MP spatial profile [group 2]) were recruited. The MP spatial profile was measured on three separate occasions. Six radiance measurements were obtained at each locus (0.25 degrees , 0.5 degrees , 1 degrees , and 1.75 degrees eccentricity; reference point, 7 degrees ). Foveal architecture was assessed by optical coherence tomography (OCT). RESULTS: Subjects who had the typical decline profile, had this profile after averaging repeated measures (group 1). Subjects who had a secondary peak, displayed the secondary peak after repeated measures were averaged (group 2). Mean SD foveal width in group 1 was significantly narrower than mean SD foveal width in group 2 (1306 +/- 240 microm and 1915 +/- 161 microm, respectively; P < 0.01). This difference remained after adjustment for sex (P < 0.001). Foveal width was significantly related to mean foveal MP, with adjustment for sex (r = 0.588, P = 0.021). Foveal profile slope was significantly related to MP spatial profile slope, after removal of an outlier (r = 0.591, P = 0.020). CONCLUSIONS: HFP reproducibly measures MP spatial profile. Secondary peaks seen in the MP spatial profile cannot be attributed to measurement error and are associated with wider foveas. The slope of an individual's MP spatial profile is related to foveal slope, with a steeper MP distribution associated with a steeper foveal depression.