Aims/Introduction: We aimed to investigate whether there are differences in the risk factors or markers for the progression of diabetic retinopathy (DR) and diabetic nephropathy (DN) in type 2 diabetes mellitus.Materials and Methods: We carried out a 3‐year retrospective cohort study of 604 patients with type 2 diabetes mellitus. The outcomes were the progression of DR (worsening of the DR stage) and DN (an estimated glomerular filtration rate decline >12%) at the 3‐year follow up. The mean hemoglobin A1c (HbA1c) level and HbA1c variability (HbA1c‐VAR) were calculated.Results: The mean HbA1c and HbA1c‐VAR levels were higher in the DR progressors (n = 67) than in the DR non‐progressors (n = 537). The mean HbA1c was a significant predictor for DR progression independent of the duration of diabetes and HbA1c‐VAR levels. The urine albumin‐to‐creatinine ratio at baseline and HbA1c‐VAR levels were higher in the DN progressors (n = 34) than in the DN non‐progressors (n = 570). The triglyceride to high‐density lipoprotein cholesterol ratio at baseline tended to be higher in the DN progressors than in the DN non‐progressors. HbA1c‐VAR levels and the triglyceride‐to‐high‐density lipoprotein cholesterol ratio were significant predictors for DN progression independent of estimated glomerular filtration rate and the urine albumin‐to‐creatinine ratio.Conclusions: Average glycemia was significantly associated with progression of DR, whereas glycemic variability and dyslipidemia were significantly associated with progression of DN in type 2 diabetes mellitus.

Ko SH, et al. J Korean Med Sci. 2014 Jul;29(7):965-972. https://doi.org/10.3346/jkms.2014.29.7.965

OBJECTIVE: We aimed to determine the effects of thyroid hormone on A1C and glycated albumin (GA) in nondiabetic patients with overt hypothyroidism. RESEARCH DESIGN AND METHODS: A1C levels were measured in 45 nondiabetic patients with overt hypothyroidism and 180 euthyroid control subjects. A1C, GA, fasting blood glucose (FBG), 1,5-anhydroglucitol, and erythrocyte indexes were determined in 30 nondiabetic patients with overt hypothyroidism before and after thyroid hormone replacement. RESULTS: A1C levels were higher in patients with hypothyroidism compared with control subjects. A1C levels were decreased by thyroid hormone replacement. Thyroid hormone replacement increased serum erythropoietin, reticulocyte count, and mean corpuscular hemoglobin (MCH). The change in A1C level was significantly correlated with the change in reticulocyte count or MCH. Thyroid hormone replacement decreased serum levels of albumin and GA. However, FBG and 1,5-anhydroglucitol levels were not altered. CONCLUSIONS: Levels of A1C and GA are spuriously high in nondiabetic patients with overt hypothyroidism.