Association Between Glycaemic Control (HbA1c) and Severity of Diabetic Retinopathy: A Hospital-Based Observational Study
DOI:
https://doi.org/10.48047/192ars28Keywords:
diabetic retinopathy, glycated haemoglobin, HbA1c, glycaemic control, diabetes mellitus, South India.Abstract
Background: Diabetic retinopathy (DR) is a leading cause of preventable visual impairment among working-age adults worldwide and an increasing burden in India. Glycated haemoglobin (HbA1c) reflects integrated glycaemic control over the preceding two to three months and is a plausible determinant of both the development and the progression of DR. We examined the association between HbA1c and the presence and severity of DR in a South Indian hospital population.
Methods: This hospital-based observational cross-sectional comparative study enrolled 200 patients with diabetes mellitus attending a tertiary care teaching hospital in South India. HbA1c was measured for all participants, and DR was graded on dilated fundus examination into No DR, Mild non-proliferative DR (NPDR), Moderate NPDR, Severe NPDR, and proliferative DR (PDR). HbA1c was categorised as good (<7%), fair (7-9%), and poor (>9%). Associations were assessed using the independent t-test, one-way analysis of variance (ANOVA), the chi-square test, and Pearson correlation, with p<0.05 considered significant.
Results: The mean age was 56.8 (SD 13.3) years and 105 (52.5%) were female. DR was present in 142 (71.0%; 95% CI 64.7-77.3%). Mean HbA1c was higher in patients with DR than without (8.70% vs 7.35%; t=9.33, p<0.001) and rose stepwise across DR severity (No DR 7.35%, Mild NPDR 8.48%, Moderate NPDR 8.48%, Severe NPDR 9.13%, PDR 10.29%; F=35.08, p<0.001). DR prevalence increased across HbA1c categories (23.8%, 67.5%, 96.4%; chi-square=41.04, p<0.001). Diabetes duration was longer in those with DR (16.5 vs 7.5 years; t=9.00, p<0.001). DR did not differ by hypertension status (p=0.84).
Conclusion: Poorer glycaemic control showed a strong, graded association with both the presence and severity of DR, supporting tight glycaemic control and regular retinal screening.
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References
Rema M, Pradeepa R. Diabetic retinopathy: an Indian perspective. Indian J Med Res. 2007;125(3):297-310. PMID: 17496357.
Raman R, Vaitheeswaran K, Vinita K, Sharma T. Is prevalence of retinopathy related to the age of onset of diabetes? Sankara Nethralaya Diabetic Retinopathy Epidemiology and Molecular Genetic Report No. 5. Ophthalmic Res. 2010;45(1):36-41. doi: 10.1159/000314720
Rodriguez-Fontal M, Kerrison JB, Alfaro DV, Jablon EP. Metabolic control and diabetic retinopathy. Curr Diabetes Rev. 2009;5(1):3-7. doi: 10.2174/157339909787314176
Ranil PK, Raman R, Rachepalli SR, Pal SS, Kulothungan V, Lakshmipathy P, et al. Anemia and diabetic retinopathy in type 2 diabetes mellitus. J Assoc Physicians India. 2010;58:91-4. PMID: 20653149.
Patel A, MacMahon S, Chalmers J, et al.; ADVANCE Collaborative Group. Intensive blood glucose control and vascular outcomes in patients with type 2 diabetes. N Engl J Med. 2008;358(24):2560-2572.
Mohamed Q, Gillies MC, Wong TY. Management of diabetic retinopathy: a systematic review. JAMA. 2007;298(8):902-916.
Klein BEK, Myers CE, Howard KP, Klein R. Serum glucose and hemoglobin A1c in relation to retinal disease and retinopathy. Arch Ophthalmol. 2010;128(5):645-651.
Raman R, Rani PK, Reddi Rachepalle S, et al. Prevalence of diabetic retinopathy in India: Sankara Nethralaya Diabetic Retinopathy Epidemiology and Molecular Genetics Study (SN-DREAMS). Ophthalmology. 2009;116(2):311-318.
Wong TY, Klein R, Islam FMA, Cotch MF, Folsom AR, Klein BEK, et al. Diabetic retinopathy in a multi-ethnic cohort in the United States. Am J Ophthalmol. 2006;141(3):446-455.
Cheung N, Mitchell P, Wong TY. Diabetic retinopathy. Lancet. 2010;376(9735):124-136.
Yau JWY, Rogers SL, Kawasaki R, et al. Global prevalence and major risk factors of diabetic retinopathy. Diabetes Care. 2012;35(3):556-564.
Stratton IM, Adler AI, Neil HAW, et al. Association of glycaemia with macrovascular and microvascular complications of type 2 diabetes (UKPDS 35): prospective observational study. BMJ. 2000;321(7258):405-412.
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