Fasting Glucose Levels, Type 2 Diabetes Duration May Predict AMD Risk

Fasting glucose levels and type 2 diabetes duration of 5 or more years may elevate the risk of age-related macular degeneration (AMD), according to a study published in Diabetes & Metabolism. Individuals with new-onset diabetes have an increased risk for wet AMD, the report shows. 

Investigators conducted a retrospective, population-based cohort study of 2,103,604 participants aged 45 years or older who did not have AMD, according to a 2009 health insurance claims database. The team observed participants between 2011 and 2018 and examined the role of fasting glucose levels and diabetic disease duration on AMD development. Study participants were stratified according to glycemic status including individuals with normal glycemic status, impaired fasting glucose, new-onset diabetes, diabetes diagnosis, and diabetes.  

A total of 49,1836 study participants (2.34%) had newly diagnosed AMD — 36,271 had dry AMD compared with 12,912 participants with wet AMD. Individuals with diabetes experienced a higher risk for dry AMD compared with participants without diabetes, and longer disease duration increased this risk even further. Among individuals with a disease duration of less than 5 years, the adjusted hazard ratio was 1.192 (95% CI, 1.141-1.245) compared with 1.294 (95% CI, 1.242-1.349) among participants with a disease duration longer than 5 years, after adjusting for age, sex, body mass index, lifestyle, and medical history. 

Study participants with new-onset diabetes had an increased risk of wet AMD (HR, 1.103; 95% CI, 1.011–1.203), and longer disease duration increased this risk further. Disease duration longer than 5 years (HR, 1.506; 95% CI, 1.413-1.605) presented a greater risk compared with a disease duration of less than 5 years (HR, 1.252; 95% CI,  (1.167-1.344), according to the report. 

Overall, the report shows that patients with AMD had older age (>65 years), higher fasting glucose levels, and larger waist circumference. These individuals also had a higher prevalence of hypertension, diabetes, and hyperlipidemia. Individuals with wet AMD were more likely to be men, current smokers, and consume large amounts of alcohol. Higher glycemic status increased AMD incidence.

“[G]lycemic status may be an independent risk factor for dry and wet AMD,” according to the researchers. “Therefore, proper glucose management from the early stage of diabetes is recommended to prevent the development of AMD because the risk of wet AMD increases upon new diabetes diagnosis. In addition, AMD screening is also recommended for long-term diabetes patients.”

Study limitations include a failure to obtain data regarding AMD grade and stage or diabetes medications, and ethnic homogeneity among the cohort, which may limit the globalization of these findings.