Kholoud Bokhary1, Feda Aljaser2, Manal Abudawood2, Hajera Tabassum3, Afnan Bakhsh3, Shatha Alhammad1, Rawan Aleyadhi1, Faisal Almajed4, Roua Alsubki2. 1. Department of Optometry and Vision Science, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia. 2. Department of Clinical Laboratory Sciences, Chair of Medical and Molecular Genetics, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia. 3. Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia. 4. Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia.
Abstract
BACKGROUND: Diabetic retinopathy (DR) is a sight-threatening complication of diabetes mellitus (DM). Oxidative stress generated on account of hyperglycemic state may lead to retinal abnormalities including DR. OBJECTIVES: The aim of the study was to evaluate the status of antioxidant enzymes; superoxide dismutase (SOD), and catalase (CAT), in different stages of DR severity in subjects with type 1 DM (T1DM) and type 2 DM (T2DM). METHODS: The cross-sectional study enrolled 148 subjects with T1DM (n = 17), T2DM (n = 96), and nondiabetic controls (n = 35). Subjects with DM were divided into 2 subgroups based on DR severity (mild-to-severe nonproliferative DR [NPDR] and proliferative DR [PDR]), and serum glycated hemoglobin (HbA1c), lipid profile, SOD, and CAT were estimated. RESULTS: Both SOD and CAT levels were lower in diabetic subjects than nondiabetic controls. A significant positive correlation was found between HbA1C level and severity of DR (p < 0.0001). Levels of SOD and CAT varied significantly with DR severity in both diabetic groups at p < 0.05. Furthermore, levels of SOD and CAT were found to decrease significantly (p < 0.001) in DR (+) compared to DR (-) patients. Also, increased levels of HbA1c were significantly associated (p < 0.001) with decreased SOD in both subgroups (NPDR and PDR). DR severity was significantly associated with SOD and CAT in the NPDR and PDR subgroups (p < 0.05). CONCLUSION: Oxidative stress and decreased antioxidant defenses are associated with DR progression to its PDR stage.
BACKGROUND: Diabetic retinopathy (DR) is a sight-threatening complication of diabetes mellitus (DM). Oxidative stress generated on account of hyperglycemic state may lead to retinal abnormalities including DR. OBJECTIVES: The aim of the study was to evaluate the status of antioxidant enzymes; superoxide dismutase (SOD), and catalase (CAT), in different stages of DR severity in subjects with type 1 DM (T1DM) and type 2 DM (T2DM). METHODS: The cross-sectional study enrolled 148 subjects with T1DM (n = 17), T2DM (n = 96), and nondiabetic controls (n = 35). Subjects with DM were divided into 2 subgroups based on DR severity (mild-to-severe nonproliferative DR [NPDR] and proliferative DR [PDR]), and serum glycated hemoglobin (HbA1c), lipid profile, SOD, and CAT were estimated. RESULTS: Both SOD and CAT levels were lower in diabetic subjects than nondiabetic controls. A significant positive correlation was found between HbA1C level and severity of DR (p < 0.0001). Levels of SOD and CAT varied significantly with DR severity in both diabetic groups at p < 0.05. Furthermore, levels of SOD and CAT were found to decrease significantly (p < 0.001) in DR (+) compared to DR (-) patients. Also, increased levels of HbA1c were significantly associated (p < 0.001) with decreased SOD in both subgroups (NPDR and PDR). DR severity was significantly associated with SOD and CAT in the NPDR and PDR subgroups (p < 0.05). CONCLUSION: Oxidative stress and decreased antioxidant defenses are associated with DR progression to its PDR stage.