Dietary fat consumption and primary open-angle glaucoma.
BACKGROUND
Prostaglandin F(2alpha) analogues are effective intraocular-pressure-lowering drugs. Dietary fatty acids affect endogenous prostaglandin F(2alpha) concentrations and may thus influence intraocular pressure.


OBJECTIVE
We prospectively examined dietary fat consumption in relation to primary open-angle glaucoma (POAG).


METHODS
Women (n = 76 199 in the Nurses' Health Study) and men (n = 40 306 in the Health Professionals Follow-Up Study) free of POAG in 1980 and 1986, respectively, were followed until 1996 if they were > or =40 y old and reported receiving eye exams during follow-up. Potential confounders were assessed on biennial questionnaires, and energy-adjusted cumulative averaged fat intakes were measured by using validated food-frequency questionnaires. We analyzed 474 self-reported POAG cases confirmed by medical chart review. Cohort-specific multivariate rate ratios (RRs) were obtained by using proportional hazards models and were then pooled.


RESULTS
Major fats and fat subtypes were not independently associated with POAG risk. Pooled multivariate RRs (95% CI) for POAG comparing the highest with the lowest quintile of fat intake were as follows: 0.90 (0.67, 1.21) for total fat, 1.03 (0.77, 1.38) for saturated fat, 0.76 (0.56, 1.03) for monounsaturated fat, and 0.87 (0.66, 1.16) for polyunsaturated fat, none of which were statistically significant. We found a suggestive positive association between a higher ratio of n-3 to n-6 polyunsaturated fat and risk of POAG [RR = 1.49 (1.11, 2.01); P for trend = 0.10], which was stronger for high-tension POAG [RR = 1.68 (1.18, 2.39); P for trend = 0.009].


CONCLUSIONS
A high ratio of n-3 to n-6 polyunsaturated fat appears to increase the risk of POAG, particularly high-tension POAG. Further studies are needed.
Kang
Jae H
JH
Department of Epidemiology, Harvard School of Public Health, Channing Laboratory, 181 Longwood Avenue, Boston, MA 02115, USA. nhjhk@channing.harvard.edu
Pasquale
Louis R
LR
Willett
Walter C
WC
Rosner
Bernard A
BA
Egan
Kathleen M
KM
Faberowski
Nicholaus
N
Hankinson
Susan E
SE
D000328:Adult; D000368:Aged; D015331:Cohort Studies; D016001:Confidence Intervals; D004032:Diet; D004041:Dietary Fats / Q000008:administration & dosage* / Q000009:adverse effects; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage / Q000009:adverse effects; D015237:Dinoprost / Q000096:biosynthesis*; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage / Q000009:adverse effects; D043371:Fatty Acids, Omega-6 / Q000008:administration & dosage / Q000009:adverse effects; D005260:Female; D005902:Glaucoma, Open-Angle / Q000453:epidemiology* / Q000209:etiology; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D016016:Proportional Hazards Models; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014481:United States / Q000453:epidemiology
D004041:Dietary Fats; D004042:Dietary Fats, Unsaturated; D015525:Fatty Acids, Omega-3; D043371:Fatty Acids, Omega-6; D015237:Dinoprost