Carbohydrate intake and risk of glaucoma in the sun cohort

To assess the association between carbohydrates (CH) intake and glaucoma incidence.

18,247 volunteer participants (183,067 person-years at risk) with 10-year of median follow-up were included in this prospective dynamic cohort. Baseline total CH intake (g/d) was categorised in quartiles and classified in nine different CH food sources. Self-reported diagnosis of glaucoma was collected at baseline and on biennial follow-up questionnaires. CH intake and glaucoma diagnosis were validated in a subsample of participants. We studied potential confounders and effect modificators, including diabetes. The relationship between CH intake and glaucoma incidence was analysed using multivariable Cox proportional hazards ratio (HR) models to adjust for potential confounding factors.

During 10 years of median follow-up, a total of 242 new cases of glaucoma were identified. Participants in the highest quartile of baseline CH intake had a significantly higher risk of glaucoma as compared to participants in the lowest quartile [HR 1.50 (95% Confidence interval (CI): 1.01-2.25), p for trend = 0.042]. None of the nine CH food groups was individually related to glaucoma. In stratified analyses, after excluding all cases of diabetes, the HR comparing extreme quartiles of CH intake was 1.77 (95% CI: 1.15-2.74).

Our results suggest that a higher intake of total carbohydrates is associated with a higher risk of incident glaucoma. The total amount of CH, rather than the specific food sources of CH, seems to play a major role, and this association does not seem to be confounded or modified by diabetic status.