Here’s an interesting study looking at the prevalence of diabetic retinopathy in patients across the spectrum of blood sugar control. It showed that individuals with a Hgb A1c greater than 5.5% have the biggest increase in retina damage due to sugar exposure. A Hgb A1c of 5.5% is equivalent to an average blood sugar of 111 mg/dL. For reference, diabetes is diagnosed when a fasting blood sugar is 126 mg/dL on two occasions. That means that individuals who have not been diagnosed with diabetes may already have retina damage from high blood sugars.
Now is the time to change. Call our office at 539-0270 to schedule an appointment with our Nutrition Counselors and take control of your blood sugar. Save your vision!
Association of A1C and Fasting Plasma Glucose Levels With Diabetic Retinopathy Prevalence in the U.S. Population
Implications for diabetes diagnostic thresholds
OBJECTIVE To examine the association of A1C levels and fasting plasma glucose (FPG) with diabetic retinopathy in the U.S. population and to compare the ability of the two glycemic measures to discriminate between people with and without retinopathy.
RESEARCH DESIGN AND METHODS This study included 1,066 individuals aged ≥40 years from the 2005–2006 National Health and Nutrition Examination Survey. A1C, FPG, and 45° color digital retinal images were assessed. Retinopathy was defined as a level ≥14 on the Early Treatment Diabetic Retinopathy Study severity scale. We used join point regression to identify linear inflections of prevalence of retinopathy in the association between A1C and FPG.
RESULTS The overall prevalence of retinopathy was 11%, which is appreciably lower than the prevalence in people with diagnosed diabetes (36%). There was a sharp increase in retinopathy prevalence in those with A1C ≥5.5% or FPG ≥5.8 mmol/l. After excluding 144 people using hypoglycemic medication, the change points for the greatest increase in retinopathy prevalence were A1C 5.5% and FPG 7.0 mmol/l. The coefficients of variation were 15.6 for A1C and 28.8 for FPG. Based on the areas under the receiver operating characteristic curves, A1C was a stronger discriminator of retinopathy (0.71 [95% CI 0.66–0.76]) than FPG (0.65 [0.60 – 0.70], P for difference = 0.009).
CONCLUSIONS The steepest increase in retinopathy prevalence occurs among individuals with A1C ≥5.5% and FPG ≥5.8 mmol/l. A1C discriminates prevalence of retinopathy better than FPG.