Glycated hemoglobin A1C level and the risk of diabetic retinopathy in Africa: A systematic review and meta-analysis Wondimeneh Shibabaw Shiferaw a, * , Tadesse Yirga Akalu c , Melaku Desta b , Ayelign Mengesha Kassie d , Pammla Margaret Petrucka e , Hilina Ketema Assefa a , Yared Asmare Aynalem a a Department of Nursing, College of Health Science, Debre Berhan University, Ethiopia b Department of Midwifery, College of Health Science, Debre Markos University, Ethiopia c Department of Nursing, College of Health Science, Debre Markos University, Ethiopia d Department of Nursing, College of Health Science, Woldia University, Ethiopia e College of Nursing, University of Saskatchewan, Academics without Borders, Canada article info Article history: Received 5 August 2020 Received in revised form 30 September 2020 Accepted 2 October 2020 Keywords: Diabetic retinopathy Retinopathy Glycemic control Glycated hemoglobin Africa abstract Background and aims: Diabetic retinopathy is a frequent cause of acquired blindness worldwide. Various studies have reported the effects of glycemic control on the risk of diabetic retinopathy, but the results remain inconclusive. Therefore, this meta-analysis was performed to determine the association between glycated hemoglobin A1C levels and diabetic retinopathy in Africa. Methods: A systematic search was performed using the PubMed, African Journals Online, Google Scholar, Scopus, and Wiley Online Library from inception to June 11, 2020, for observational studies addressing the association of hemoglobin A1c levels with diabetic retinopathy. The I 2 statistic was used to check heterogeneity across the included studies. A random-effects model was applied to estimate the pooled effect size (OR) and respective 95% confidence interval across studies. A funnel plot and Egger’s regression test were used to determine the presence of publication bias. Sensitivity analysis was used to determine the effect of a single study on the overall estimation. All statistical analyses were performed using STATA™ Version 14 software. Result: A total of 23 articles with 18,099 study participants were included in this meta-analysis. In the present review, when HbA1c was analyzed as a categorical variable, poor glycemic control (HbA1c >7%) was associated with an increased risk of diabetic retinopathy when compared with good glycemic control (OR ¼ 1.25; 95% CI; 1.14,1.38). Similarly, when HbA1c was analyzed as a continuous variable, a higher HbA1c was associated with an increased risk of diabetic retinopathy (MD: 0.42, 95% CI; 0.11,0.98). Conclusion: Our meta-analysis indicated evidence for poor glycemic control as an independent risk factor for the development of diabetic retinopathy in patients with diabetes mellitus. Therefore, the authors suggest that clinicians should advise their patients with diabetes to maintain their HbA1c levels within the normal range. © 2020 Diabetes India. Published by Elsevier Ltd. All rights reserved. 1. Background Globally, the burden of diabetes mellitus (DM) is rising dramatically and reaching epidemic proportions [1]. According to the World Health Organization (WHO) estimations, there were approximately 422 million adults living with diabetes mellitus globally [2], while the International Diabetes Federation (IDF) es- timates 425 million people were affected in 2017 with projection of 629 million by 2045 [3]. Approximately 80% of affected individuals live in low- and middle-income countries [4]. In Sub-Saharan Africa (SSA), more than 12 million people have diabetes, and there are 330,000 diabetes-related deaths annually, yet less than 1% of health expenditure is allocated for diabetes [5]. It has become a chronic Abbreviations: ADA, America diabetic association; DR, diabetic retinopathy; DM, diabetes mellitus; HbA1c, glycated hemoglobin level; IDF, International Diabetes Federation; NOS, Newcastle-Ottawa Scale; MOOSE, Meta-analysis Of Observational Studies in Epidemiology; WHO, World Health Organization. * Corresponding author. P.O. Box 445, Debre Berhan University, Ethiopia. E-mail address: wshibabaw2015@gmail.com (W.S. Shiferaw). Contents lists available at ScienceDirect Diabetes & Metabolic Syndrome: Clinical Research & Reviews journal homepage: www.elsevier.com/locate/dsx https://doi.org/10.1016/j.dsx.2020.10.003 1871-4021/© 2020 Diabetes India. Published by Elsevier Ltd. All rights reserved. Diabetes & Metabolic Syndrome: Clinical Research & Reviews 14 (2020) 1941e1949