Hemoglobin A1c and Fasting Plasma Glucose Levels as Predictors of Retinopathy at 10 Years

Abstract

Background: Hyperglycaemia is associated with retinopathy, and this cross-sectional relation has been used to define thresholds for defining diabetes. We evaluate the predictive values of HbA 1c and fasting plasma glucose (FPG) for retinopathy, ten years after the baseline examination.Methods: 700 men and women from the D.E.S.I.R. study were evaluated for retinopathy using a nonmydriatic digital camera. Over the preceding nine years: 235 had diabetes (treated or FPG>7.0 mmol/l at least once), 227 had an impaired fasting glucose (IFG:6.1-6.9 mmol/l) at least once, 238 always had normal glucose levels (<6.1 mmol/l). Results:The 44 participants with retinopathy at ten years had higher baseline mean (SD) for FPG and HbA 1c , than those without retinopathy, 7.24mmol/l (2.72) vs 5.90mmol/l (1.22) and 6.4% (1.6) vs 5.7% (0.7) (both P<0.0001). The frequency of retinopathy at ten years, standardized according to the distribution of glycaemia across the entire D.E.S.I.R. population was 3.6%. In our population, FPGs of 6.0mmol/l and 6.5mmol/l had positive predictive values of 8.2% and 15.4% respectively for retinopathy at ten years, and HbA 1c s of 6.0% and 6.5%: 6.0% and 14.8%. After ten years of follow-up, retinopathy was equally frequent in IFG and in those who became diabetic during the study: 8.6% and 6.7% respectively, lower than in those diabetic at baseline 13.9%. Conclusion:As the positive predictive values for retinopathy increased sharply from 6.0 mmol/l for FPG, and from 6.0% for HbA 1c , these thresholds are proposed to identify those at risk of retinopathy ten years later.

Diabetic retinopathy incidence, predictors and its association with longitudinal fasting blood sugar level changes among diabetes mellitus patients in Ethiopia: joint model

“…Specifically, an increase of one unit in the log-transformed fasting blood sugar level over the past three months corresponded to a 4.2-fold increase in the risk of developing DR. These results are consistent with previous studies done at the Arbaminch General Hospital and in France, which demonstrated a strong relationship between elevated levels of hemoglobin A1c and fasting plasma glucose for the presence of diabetic retinopathy ( 33 , 37 ). These findings suggest that higher fasting blood glucose levels, indicative of inadequate blood glucose control, may contribute to the development of diabetic retinopathy.…”

Diabetic retinopathy incidence, predictors and its association with longitudinal fasting blood sugar level changes among diabetes mellitus patients in Ethiopia: joint model

“…Specifically, an increase of one unit in the log-transformed fasting blood sugar level over the past three months corresponded to a 4.2-fold increase in the risk of developing DR. These results are consistent with previous studies done at the Arbaminch General Hospital and in France, which demonstrated a strong relationship between elevated levels of hemoglobin A1c and fasting plasma glucose for the presence of diabetic retinopathy ( 33 , 37 ). These findings suggest that higher fasting blood glucose levels, indicative of inadequate blood glucose control, may contribute to the development of diabetic retinopathy.…”

Application of semiparametric model in modelling diabetic retinopathy among type II diabetic patients

“…Despite the nonlinear relationship, a semiparametric model based on the tensor product of HbA1c and FBG suggested that the combination of a high level of HbA1c and a high level of FBG resulted in a higher risk of being diabetic retinopathy. Our study finding agrees with a study that used 10-year follow-up data [20]. Their finding suggested that patients with diabetic retinopathy at the baseline had a high level of FBG and a high level of HbA1c.…”

Semiparametric modelling of diabetic retinopathy among people with type II diabetes mellitus

“…The other interesting finding of our study was the significant nonlinear relationship between interaction and the log odds of having DR. Despite the nonlinear relationship, a semiparametric model based on the tensor product of HbA1c and FBG suggested that the combination of a high level of HbA1c and a high level of FBG resulted in a higher risk of being DR. Our study finding agrees with a study that used 10-year follow-up data [ 22 ]. Their finding suggested that patients with DR at the baseline had a high level of FBG and a high level of HbA1c.…”

Diabetic retinopathy incidence, predictors and its association with longitudinal fasting blood sugar level changes among diabetes mellitus patients in Ethiopia: joint model

“…Specifically, an increase of one unit in the log-transformed fasting blood sugar level over the past three months corresponded to a 4.2-fold increase in the risk of developing DR. These results are consistent with previous studies done at the Arbaminch General Hospital and in France, which demonstrated a strong relationship between elevated levels of hemoglobin A1c and fasting plasma glucose for the presence of diabetic retinopathy ( 33 , 37 ). These findings suggest that higher fasting blood glucose levels, indicative of inadequate blood glucose control, may contribute to the development of diabetic retinopathy.…”

Application of semiparametric model in modelling diabetic retinopathy among type II diabetic patients

“…Despite the nonlinear relationship, a semiparametric model based on the tensor product of HbA1c and FBG suggested that the combination of a high level of HbA1c and a high level of FBG resulted in a higher risk of being diabetic retinopathy. Our study finding agrees with a study that used 10-year follow-up data [20]. Their finding suggested that patients with diabetic retinopathy at the baseline had a high level of FBG and a high level of HbA1c.…”

Semiparametric modelling of diabetic retinopathy among people with type II diabetes mellitus

“…The other interesting finding of our study was the significant nonlinear relationship between interaction and the log odds of having DR. Despite the nonlinear relationship, a semiparametric model based on the tensor product of HbA1c and FBG suggested that the combination of a high level of HbA1c and a high level of FBG resulted in a higher risk of being DR. Our study finding agrees with a study that used 10-year follow-up data [ 22 ]. Their finding suggested that patients with DR at the baseline had a high level of FBG and a high level of HbA1c.…”

Diabetic retinopathy incidence, predictors and its association with longitudinal fasting blood sugar level changes among diabetes mellitus patients in Ethiopia: joint model

“…Specifically, an increase of one unit in the log-transformed fasting blood sugar level over the past three months corresponded to a 4.2-fold increase in the risk of developing DR. These results are consistent with previous studies done at the Arbaminch General Hospital and in France, which demonstrated a strong relationship between elevated levels of hemoglobin A1c and fasting plasma glucose for the presence of diabetic retinopathy ( 33 , 37 ). These findings suggest that higher fasting blood glucose levels, indicative of inadequate blood glucose control, may contribute to the development of diabetic retinopathy.…”

Application of semiparametric model in modelling diabetic retinopathy among type II diabetic patients

“…Despite the nonlinear relationship, a semiparametric model based on the tensor product of HbA1c and FBG suggested that the combination of a high level of HbA1c and a high level of FBG resulted in a higher risk of being diabetic retinopathy. Our study finding agrees with a study that used 10-year follow-up data [20]. Their finding suggested that patients with diabetic retinopathy at the baseline had a high level of FBG and a high level of HbA1c.…”

Semiparametric modelling of diabetic retinopathy among people with type II diabetes mellitus

“…The other interesting finding of our study was the significant nonlinear relationship between interaction and the log odds of having DR. Despite the nonlinear relationship, a semiparametric model based on the tensor product of HbA1c and FBG suggested that the combination of a high level of HbA1c and a high level of FBG resulted in a higher risk of being DR. Our study finding agrees with a study that used 10-year follow-up data [ 22 ]. Their finding suggested that patients with DR at the baseline had a high level of FBG and a high level of HbA1c.…”