title: Association of fasting insulin and C peptide with diabetic retinopathy in Latinos with type 2 diabetes.
abstract: OBJECTIVE
  Residual insulin secretion provides important protection against the development of diabetic retinopathy in type 1 diabetes. The data to support this in type 2 diabetes are unclear. We therefore tested in type 2 diabetes whether markers of residual beta-cell function are associated with the development of diabetic retinopathy, an important microvascular complication of diabetes.
  
  
  METHODS
  Prospective, cross-sectional, family-based study.
  
  
  METHODS
  585 Latino type 2 diabetic participants, ascertained in families via a proband either with known diabetes duration of greater than 10 years and/or with diabetic retinopathy.
  
  
  METHODS
  CIRCULATING LEVELS OF FASTING INSULIN AND C PEPTIDE MEASURED AND CORRELATED TO DEGREE OF DIABETIC RETINOPATHY, ASSESSED BY DIGITAL FUNDUS PHOTOGRAPHY AND GRADED USING THE MODIFIED AIRLIE HOUSE CLASSIFICATION AND THE EARLY TREATMENT DIABETIC RETINOPATHY STUDY SCALE (RANGE: levels 10-85).
  
  
  RESULTS
  Fasting plasma insulin (β=-0.29; 95% CI -0.38 to -0.20; p<0.0001) and C peptide (β=-0.21; 95% CI -0.30 to -0.13; p<0.0001) concentrations in these diabetic participants were significantly correlated with retinopathy and its degree of severity. This relationship remained significant after adjusting for potential covariates including age, gender, glycosylated hemoglobin, duration of diabetes, blood pressure, and renal function.
  
  
  CONCLUSIONS
  These data suggest that residual endogenous insulin secretion is associated with the presence of diabetic retinopathy and its severity in Latinos with familial type 2 diabetes. It remains to be proven whether beta-cell targeted therapies, to maintain beta-cell mass and/or function in addition to glycemic control, will further the goal of preventing diabetic microvascular disease.
authors.affiliation: Shiley Eye Center and Department of Ophthalmology, University of California at San Diego , La Jolla, California , USA.
authors.forename: Jane Z
authors.initials: JZ
authors.lastname: Kuo
authors.affiliation: Institute for Translational Genomics and Population Sciences, Los Angeles BioMedical Research Institute, Harbor-UCLA Medical Center , Torrance, California , USA.
authors.forename: Xiuqing
authors.initials: X
authors.lastname: Guo
authors.affiliation: Department of Ophthalmology & Visual Sciences , University of Wisconsin School of Medicine and Public Health , Madison, Wisconsin , USA.
authors.forename: Ronald
authors.initials: R
authors.lastname: Klein
authors.affiliation: Department of Ophthalmology & Visual Sciences , University of Wisconsin School of Medicine and Public Health , Madison, Wisconsin , USA.
authors.forename: Barbara E
authors.initials: BE
authors.lastname: Klein
authors.affiliation: Shiley Eye Center and Department of Ophthalmology, University of California at San Diego , La Jolla, California , USA.
authors.forename: Robert N
authors.initials: RN
authors.lastname: Weinreb
authors.affiliation: Division of Endocrinology and Metabolism , Los Angeles BioMedical Research Institute, Harbor-UCLA Medical Center , Torrance, California , USA.
authors.forename: Pauline
authors.initials: P
authors.lastname: Genter
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine , Tri-Service General Hospital, National Defense Medical Center , Taipei , Taiwan.
authors.forename: Fone-Ching
authors.initials: FC
authors.lastname: Hsiao
authors.affiliation: Division of Endocrinology, Diabetes and Metabolism , Cedars-Sinai Medical Center , Los Angeles, California , USA.
authors.forename: Mark O
authors.initials: MO
authors.lastname: Goodarzi
authors.affiliation: Institute for Translational Genomics and Population Sciences, Los Angeles BioMedical Research Institute, Harbor-UCLA Medical Center , Torrance, California , USA.
authors.forename: Jerome I
authors.initials: JI
authors.lastname: Rotter
authors.affiliation: Institute for Translational Genomics and Population Sciences, Los Angeles BioMedical Research Institute, Harbor-UCLA Medical Center , Torrance, California , USA.
authors.forename: Yii-Der Ida
authors.initials: YD
authors.lastname: Chen
authors.affiliation: Division of Endocrinology and Metabolism , Los Angeles BioMedical Research Institute, Harbor-UCLA Medical Center , Torrance, California , USA.
authors.forename: Eli
authors.initials: E
authors.lastname: Ipp
keywords: C-Peptide; Insulin; Retinopathy