title: Risk factors for development and progression of nonproliferative retinopathy in normoalbuminuric patients with type 1 diabetes.
abstract: BACKGROUND
  The aim of this study was to evaluate risk factors for development and progression of nonproliferative retinopathy (NPR) in normoalbuminuric patients with type 1 diabetes mellitus (T1DM).
  
  
  METHODS
  A total of 223 T1DM with normal renal function and normoalbuminuria were included in this study and followed for 48 months. Photodocumented retinopathy status was made according to the EURODIAB protocol. Urinary albumin excretion rate (UAE) was measured from at least two 24-h urine samples. Possible risk factors for development or progression of NPR were examined in backward stepwise Cox's multiple regression analysis.
  
  
  RESULTS
  The majority of patients (70%) had no retinopathy while 67 (30%) had NPR at baseline. Patients with NPR were older, had longer duration of diabetes, higher systolic blood pressure, BMI, resting heart rate, UAE and lower estimated glomerular filtration rate (p ≤ 0.04 for all). After 48 months 24 patients (10.7%) developed NPR or progressed to proliferative retinopathy. Systolic blood pressure (HR 1.03, CI 1.01-1.05, p=0.02), UAE (HR 1.14, CI 1.07-1.21, p<0.001), and resting heart rate (HR 1.05, CI 1.01-1.09, p=0.006) were significantly associated with development or progression of NPR.
  
  
  CONCLUSIONS
  Our results suggest that retinopathy is present and may progress in T1DM even when coexisting renal disease is excluded. Normoalbuminuric T1DM requires close monitoring for the early detection of retinopathy, especially if they have a higher UAE, systolic blood pressure and resting heart rate.
authors.affiliation: Vuk Vrhovac Clinic for Diabetes, Endocrinology and Metabolic Diseases, University Hospital Merkur, Medical School, University of Zagreb, Zagreb, Croatia. Electronic address: tbulum@idb.hr.
authors.forename: Tomislav
authors.initials: T
authors.lastname: Bulum
authors.affiliation: Vuk Vrhovac Clinic for Diabetes, Endocrinology and Metabolic Diseases, University Hospital Merkur, Medical School, University of Zagreb, Zagreb, Croatia.
authors.forename: Kristina
authors.initials: K
authors.lastname: Blaslov
authors.affiliation: Vuk Vrhovac Clinic for Diabetes, Endocrinology and Metabolic Diseases, University Hospital Merkur, Medical School, University of Zagreb, Zagreb, Croatia.
authors.forename: Lea
authors.initials: L
authors.lastname: Duvnjak
mesh_terms: D000328:Adult; D000368:Aged; D000419:Albuminuria / Q000652:urine; D017523:Croatia / Q000453:epidemiology; D003922:Diabetes Mellitus, Type 1 / Q000150:complications* / Q000652:urine; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012160:Retina / Q000473:pathology; D012164:Retinal Diseases / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D012189:Retrospective Studies; D012307:Risk Factors; D055815:Young Adult
keywords: Albuminuria; Microvascular complications; Retinopathy; Type 1 diabetes