Published: 2020-02-24

Serum high sensitivity C reactive protein levels in patients with diabetic retinopathy: a cross sectional study

Harishchandra R. Chaudhari, Gaurav A. Chaudhari


Background: Diabetic retinopathy (DR) is one of the major visual morbidities associated with diabetes. This study determined the levels of serum high-sensitivity C-reactive protein (hs-CRP) in patients with DR and to correlate the estimated levels of serum hs-CRP with the severity of DR and other coexisting factors.

Methods: This was a cross-sectional study conducted between March 2009 and August 2010 and included patients with type 2 diabetes mellitus (T2DM) with or without DR. A detailed fundus evaluation was performed using direct and indirect ophthalmoscopy. The retinopathies were observed and documented in accordance with the Kanski's system of classification as background DR (BDR), pre-proliferative DR (PPDR), and proliferative DR (PDR). Laboratory investigations determined the levels of fasting blood glucose (FBG), postprandial blood glucose (PPBG), glycosylated hemoglobin, urine albumin excretion, and serum hs-CRP levels.

Results: In total, 80 patients with T2DM were included (DR group, n=40 [BDR, n=22; PDR, n=11; PPDR, n=7]; control group, n=40). Highest serum hs-CRP levels were found in PDR group (6.68 mg/L), followed by PPDR and BDR group (3.2 mg/L and 1.56 mg/L, respectively). The PDR group showed the longest duration of diabetes (16 years), highest FBG (221.8 mg/dL) and HbA1c (6.68 mg/L). The incidence of albuminuria and maculopathy was higher in PDR group (72.7% and 54.54%, respectively). A significant association of hs-CRP levels with DR in patients with T2DM was observed. A significantly (<0.005) positive correlation of hs-CRP was also observed with age, duration of disease, FBG, PPBG, and HbA1c.

Conclusions: Patients with severe grades of retinopathy had significantly higher hs-CRP levels than patients with the milder grades.


Diabetes, Fundus, Glycemic control, Kanski's system, Proliferative

Full Text:



Targher G, Bertolini L, Zenari L, Lippi G, Pichiri I, Zoppini G, et al. Diabetic retinopathy is associated with an increased incidence of cardiovascular events in Type 2 diabetic patients. Diabet Med. 2008; 25:45-50.

Holekamp N. Overview of diabetic macular edema. Am J Manag Care. 2016;22:S284-91.

Prevalence of diabetic retinopathy in India is 16.9%: Survey. Available at: Accessed 26th December 2019.

Vainas T, Stassen F, Graff R, Twiss E, Herngreen S, Welton R, et al. C-reactive protein in peripheral arterial disease: relation to severity of the disease and to future cardiovascular events. J Vasc Surg. 2005;42:243-51.

Navarro J, Mora C. Role of inflammation in diabetic complications. Nephrol Dial Transplant. 2005;20: 2601-4.

Arar NH, Freedman BI, Adler SG, Iyengar SK, Chew EY, Davis MD, et al. Heritability of the severity of diabetic retinopathy: the FIND-Eye study. Invest Ophthalmol Vis Sci. 2008;49:3839-45.

Ng DP. Human genetics of diabetic retinopathy: current perspectives. J Ophthalmol. 2010; 2010:172593.

Heng LZ, Comyn O, Peto T, Tadros C, Ng E, Sivaprasad S, et al. Diabetic retinopathy: pathogenesis, clinical grading, management and future developments. Diabet Med. 2013;30:640-50.

Rangasamy S, McGuire PG, Das A. Diabetic retinopathy and inflammation: novel therapeutic targets. Middle East Afr J Ophthalmol. 2012;19:52-9.

Peng D, Wang J, Zhang R, Tang S, Jiang F, Chen M, et al. C-reactive protein genetic variant is associated with diabetic retinopathy in Chinese patients with type 2 diabetes. BMC Endocr Disord. 2015; 2(15):8.

Hayashino Y, Mashitani T, Tsujii S, Ishii H, Diabetes Distress and Care Registry at Tenri Study Group. Serum high-sensitivity C-reactive protein levels are associated with high risk of development, not progression, of diabetic nephropathy among Japanese type 2 diabetic patients: a prospective cohort study (Diabetes Distress and Care Registry at Tenri [DDCRT7]). Diabetes Care. 2014;37:2947-52.

Tsunoda K, Arita M, Yukawa M, Ueyama M, Furuta M, Nakagawa T, et al. Retinopathy and hypertension affect serum high-sensitivity C-reactive protein levels in type 2 diabetic patients. J Diabetes Complica. 2005;19:123-7.

Gopinath G, Kakkanatt V, Bisto AA, Mathai MT. Correlation of C-reactive protein and glycosylated hemoglobin on severity of diabetic macular edema. Kerala J Ophthalmol. 2019;31:131-7.

Song J, Chen S, Liu X, Duan H, Kong J, Li Z. Relationship between C-Reactive protein level and diabetic retinopathy: a systematic review and meta-analysis. PLoS ONE. 2015;10:e0144406.

Chen YS. Contents changes and correlations between homocysteine and cystatin C in patients with diabetic retinopathy in type 2 diabetes mellitus. Int J Ophthalmol. 2010;10:2107-10.

Jia ZT, Liu CY, Li H. Changes of the concentration of serum ischemia modified albumin and high sensitivity C-reactive protein in type 2 diabetic patients with retinopathy]. Zhonghua Yan Ke Za Zhi. 2009;45:805-8.

Pepys MB, Hirschfield GM. C‐reactive protein: a critical update. J Clin Invest. 2003;111:1805-12.

Fong DS, Aiello LP, Ferris FL Klein R. Diabetic retinopathy. Diabetes Care. 2004;27:2540‑53.

Bertin E, Nguyen P, Guenounou M, Durlach V, Potron G, Leutenegger M. Plasma levels of tumor necrosis factor-alpha (TNF-alpha) are essentially dependent on visceral fat amount in type 2 diabetic patients. Diabetes Metab. 2000;26:178-82.

Engelsen D, Koekkoek P, Gorter K, Donk M, Salome P, Rutten G. High-sensitivity C-reactive protein to detect metabolic syndrome in a centrally obese population: a cross-sectional analysis. Cardiovasc Diabetol. 2012;11:25.

Chuengsamarn S, Rattanamongkolgul S, Sittithumcharee G, Jirawatnotai S. Association of serum high-sensitivity C-reactive protein with metabolic control and diabetic chronic vascular complications in patients with type 2 diabetes. Diabetes Metab Syndr. 2017;11:103-8.

Rani PK, Raman R, Gupta A, Pal SS, Kulothungan V, Sharma T. Albuminuria and diabetic retinopathy in type 2 diabetes mellitus Sankara Nethralaya diabetic retinopathy epidemiology and molecular genetic study (SN-DREAMS, report 12). Diabetol Metab Syndr. 2011;3:9.

Boelter MC, Gross JL, Canani LH, Costa LA, Lisboa HR, Três GS, et al. Proliferative diabetic retinopathy is associated with microalbuminuria in patients with type 2 diabetes. Braz J Med Biol Res. 2006;39:1033-9.

Ra H, Yoo JH, Ban WH, Song HC, Lee SS, Kim SR, et al. Predictors for diabetic retinopathy in normoalbuminuric people with type 2 diabetes mellitus. Diabetol Metab Syndr. 2012;4:29.

Zander E, Herfurth S, Bohl B, Heinke P, Herrmann U, Kohnert K, et al. Maculopathy in patients with diabetes mellitus type 1 and type 2: associations with risk factors. B J Ophthalmol. 2000;84:871-6.

Diabetes Prevention Program Research Group. The prevalence of retinopathy in impaired glucose tolerance and recent-onset diabetes in the Diabetes Prevention Program. Diabet Med. 2007;24:137-44.

Tomić M, Ljubić S, Kaštelan S, Gverović Antunica A, Jazbec A, Poljičanin T. Inflammation, haemostatic disturbance, and obesity: possible link to pathogenesis of diabetic retinopathy in type 2 diabetes. Mediators Inflamm. 2013;2013:818671.

Blum A, Socea D, Ben-Shushan RS, Keinan-Boker L, Naftali M, Segol G, et al. A decrease in VEGF and inflammatory markers is associated with diabetic proliferative retinopathy. Eur Cytokine Netw. 2012;23:158-62.