title: The Wisconsin Epidemiologic Study of Diabetic Retinopathy. XVI. The relationship of C-peptide to the incidence and progression of diabetic retinopathy.
abstract: The relationship between plasma C-peptide and the 6-year incidence and progression of diabetic retinopathy was examined in a population-based study in Wisconsin. Individuals with younger-onset (n = 548) and older-onset (n = 459) diabetes were included. C-peptide was measured by radioimmunoassay with Heding's M1230 antiserum. Retinopathy was determined from stereoscopic fundus photographs. Younger- and older-onset insulin-using individuals with undetectable or low plasma C-peptide (< 0.3 nmol/l) at baseline had the highest incidence and rates of progression of retinopathy, whereas older-onset individuals with C-peptides > 0.3 nmol/l had the lowest incidence and rates of progression of retinopathy. However, within each group (younger-onset using insulin, older-onset using insulin, and older-onset not using insulin), after we controlled for other characteristics associated with retinopathy, there was no relationship between higher levels of C-peptide at baseline and lower 6-year incidence or progression of retinopathy. These data suggest that glycemic control, and not C-peptide, is related to the incidence and progression of diabetic retinopathy.
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Wisconsin Medical School, Madison 53705-2397, USA.
authors.forename: R
authors.initials: R
authors.lastname: Klein
authors.forename: B E
authors.initials: BE
authors.lastname: Klein
authors.forename: S E
authors.initials: SE
authors.lastname: Moss
mesh_terms: D000328:Adult; D017668:Age of Onset; D015415:Biomarkers / Q000097:blood; D001794:Blood Pressure; D015992:Body Mass Index; D002096:C-Peptide / Q000097:blood*; D003920:Diabetes Mellitus / Q000453:epidemiology; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000503:physiopathology*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000503:physiopathology*; D003930:Diabetic Retinopathy / Q000097:blood / Q000453:epidemiology* / Q000503:physiopathology*; D018450:Disease Progression; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D015994:Incidence; D007328:Insulin / Q000097:blood; D008297:Male; D009765:Obesity; D011507:Proteinuria; D014922:Wisconsin / Q000453:epidemiology
chemical_list: D015415:Biomarkers; D002096:C-Peptide; D006442:Glycated Hemoglobin; D007328:Insulin