Heavy total alcohol consumption was reported to increase the risk of development and progression of diabetic retinopathy. However, differing from total alcohol consumption, whether the quantity of alcohol intake per occasion had harmful or beneficial effects related to severe eye diseases caused by diabetes remains unknown. To clarify this, we utilized ICD-10 and medical treatment codes from a nationwide claims database that finally included 21,392 men with type 2 diabetes (mean age 53 y, HbA1c 7.0%, mean follow-up period 4.3 y). During the study period, 425 patients developed vision-threatening treatment-required diabetic eye diseases (TRDED) (4.6/1000 person-years). Multivariate Cox analysis demonstrated that a large quantity of alcohol per occasion defined as ≥3 drinks per occasion was positively associated with future occurrence of TRDED. One drink was defined as a standard Japanese drink with a volume equivalent to 23 g ethanol. Hazard ratio in patients drinking large amounts of alcohol per occasion for incident TRDED was 4.49 (95% confidence interval, 1.98-10.19) compared with the reference group (≤1 drink per occasion) after adjusting for covariates including total alcohol consumption. This finding demonstrated that a large quantity of alcohol per occasion had a significant association with future vision-threatening retinopathy in men with type 2 diabetes. The mechanism of this finding with regard to severe retinopathy awaits further research.
M. Yamamoto: None. T. Yamada: None. S. Kodama: None. H. Sone: Research Support; Self; Astellas Pharma Inc., Eisai Co., Ltd., Kyowa Kirin Co., Ltd., Novo Nordisk, Ono Pharmaceutical Co., Ltd., Taisho Pharmaceutical Co., Ltd., Takeda Pharmaceutical Co. K. Fujihara: None. Y. Yaguchi: None. T. Osawa: None. M. Kaneko: None. M. Kitazawa: None. T. Sato: None. M. H. Yamada: None. Y. Matsubayashi: None.