Dataset Information

Smoking, dietary betaine, methionine, and vitamin D in monozygotic twins with discordant macular degeneration: epigenetic implications.

ABSTRACT:

Objective

We evaluated monozygotic twin pairs with discordant age-related macular degeneration (AMD) phenotypes to assess differences in behavioral and nutritional factors.

Design

Case series.

Participants

Caucasian male twin pairs from the United States Twin Study of Macular Degeneration.

Methods

Twin pairs were genotyped to confirm monozygosity. Ocular characteristics were evaluated based on fundus photographs using the Wisconsin Grading System and a 5-grade Clinical Age-Related Maculopathy Staging System. We selected twin pairs discordant in each of the following phenotypic categories: Stage of AMD (n = 28), drusen area (n = 60), drusen size (n = 40), and increased pigment area (n = 56). The Wilcoxon signed-rank test and linear regression were used to assess associations between behavioral and nutritional characteristics and each phenotype within discordant twin pairs.

Main outcome measures

Differences in smoking and dietary factors within twin pairs discordant for stage of AMD, drusen area, drusen size, and pigment area.

Results

Representative fundus photographs depict the discordant phenotypes. Pack-years of smoking were higher for the twin with the more advanced stage of AMD (P = 0.05). Higher dietary intake of vitamin D was present in the twins with less severe AMD (P = 0.01) and smaller drusen size (P = 0.05) compared with co-twins, adjusted for smoking and age. Dietary intakes of betaine and methionine were significantly higher in the twin with lower stage of AMD (P = 0.009) and smaller drusen area (P = 0.03), respectively.

Conclusions

The twin with the more advanced stage of AMD, larger drusen area, drusen size, and pigment area tended to be the heavier smoker. The twin with the earlier stage of AMD, smaller drusen size and area, and less pigment tended to have higher dietary vitamin D, betaine, or methionine intake. Results suggest that behavioral and nutritional factors associated with epigenetic mechanisms are involved in the etiology of AMD, in addition to genetic susceptibility.

SUBMITTER: Seddon JM

PROVIDER: S-EPMC3711586 | biostudies-literature | 2011 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Smoking, dietary betaine, methionine, and vitamin D in monozygotic twins with discordant macular degeneration: epigenetic implications.

Seddon Johanna M JM Reynolds Robyn R Shah Heeral R HR Rosner Bernard B

Ophthalmology 20110528 7

<h4>Objective</h4>We evaluated monozygotic twin pairs with discordant age-related macular degeneration (AMD) phenotypes to assess differences in behavioral and nutritional factors.<h4>Design</h4>Case series.<h4>Participants</h4>Caucasian male twin pairs from the United States Twin Study of Macular Degeneration.<h4>Methods</h4>Twin pairs were genotyped to confirm monozygosity. Ocular characteristics were evaluated based on fundus photographs using the Wisconsin Grading System and a 5-grade Clinic ...[more]

PMID: 21620475

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Dataset Information

Smoking, dietary betaine, methionine, and vitamin D in monozygotic twins with discordant macular degeneration: epigenetic implications.

Objective

Design

Participants

Methods

Main outcome measures

Results

Conclusions

Publications

Smoking, dietary betaine, methionine, and vitamin D in monozygotic twins with discordant macular degeneration: epigenetic implications.

Similar Datasets

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