title: Cystatin C, chronic kidney disease and retinopathy in adults without diabetes.
abstract: Serum cystatin C, a novel marker of renal function has been shown to be superior to serum creatinine in predicting renal function decline and adverse outcomes of chronic kidney disease (CKD). Our aim was to investigate the association between cystatin C and retinopathy in adults without diabetes.
  
  
  
  We examined 1725 Indian adults, aged 40-80 years who participated in the Singapore Indian Eye Study (2007-2009) and were free of diabetes mellitus. CKD was defined as an estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m(2) determined from serum cystatin C (CKD-eGFRcys, n = 199), and serum creatinine (CKD-eGFRcr, n = 81). Retinopathy was assessed from digital fundus photographs of both eyes by trained graders using the modified Airlie House classification. The associations of CKD defined by the two markers alone and in combination (confirmed CKD, eGFRcr <60 and eGFRcys <60, n = 58) with retinopathy were examined using logistic regression models adjusted for potential confounding factors including preexisting cardiovascular disease and albuminuria.
  
  
  
  The prevalence of retinopathy among those with CKD-eGFRcr and CKD-eGFRcys was 9.9% and 8.5%, respectively. In separate models, the associations of retinopathy with both CKD-eGFRcys (odds ratio (OR) (95% confidence interval (CI)) = 2.18 (1.14-4.16)) and CKD-eGFRcr were significant (OR (95% CI) = 2.63 (1.10-6.28)). In models including both markers, compared to optimal kidney function (eGFRcr ≥60 and eGFRcys ≥60), confirmed CKD was associated with a fourfold higher odds of retinopathy (OR (95% CI) = 4.01 (1.52-10.60)).
  
  
  
  In a population-based sample of Indian adults without diabetes, CKD defined by both cystatin C and creatinine was strongly associated with retinopathy.
authors.affiliation: Singapore National Eye Centre, Singapore.
authors.forename: Wei Yan
authors.initials: WY
authors.lastname: Ng
authors.affiliation: Department of Medicine, National University of Singapore, Singapore.
authors.forename: Boon Wee
authors.initials: BW
authors.lastname: Teo
authors.affiliation: Department of Medicine, National University of Singapore, Singapore.
authors.forename: E Shyong
authors.initials: ES
authors.lastname: Tai
authors.affiliation: Department of Pathology, National University of Singapore, Singapore.
authors.forename: Sunil
authors.initials: S
authors.lastname: Sethi
authors.affiliation: Singapore Eye Research Institute, Singapore Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore Department of Ophthalmology, National University of Singapore, Singapore.
authors.forename: Ecosse
authors.initials: E
authors.lastname: Lamoureux
authors.affiliation: Singapore National Eye Centre, Singapore Singapore Eye Research Institute, Singapore Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore Department of Ophthalmology, National University of Singapore, Singapore.
authors.forename: Wong
authors.initials: W
authors.lastname: Tien Yin
authors.affiliation: Singapore Eye Research Institute, Singapore Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore Department of Ophthalmology, National University of Singapore, Singapore charumathi.sabanayagam@seri.com.sg.
authors.forename: Charumathi
authors.initials: C
authors.lastname: Sabanayagam
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D055316:Cystatin C / Q000097:blood*; D003920:Diabetes Mellitus; D005260:Female; D006801:Humans; D007194:India / Q000208:ethnology; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D015995:Prevalence; D051436:Renal Insufficiency, Chronic / Q000097:blood* / Q000208:ethnology; D012164:Retinal Diseases / Q000097:blood* / Q000208:ethnology; D018570:Risk Assessment; D012307:Risk Factors; D012846:Singapore / Q000453:epidemiology
chemical_list: D015415:Biomarkers; D055316:Cystatin C
keywords: Creatinine; cystatin C; eGFR; retinopathy