title: Moderate-to-severe diabetic retinopathy is more prevalent in Mexico City than in San Antonio, Texas.
abstract: OBJECTIVE
  To compare the prevalence of diabetic retinopathy (DR) between low-income Mexicans from Mexico City and Mexican-Americans from San Antonio, Texas.
  
  
  METHODS
  We designed a cross-sectional population-based study in low-income neighborhoods of Mexico City and San Antonio. The men and non-pregnant women included in the study had NIDDM and were between 35 and 64 years of age. Ophthalmologic evaluation was performed in 414 patients, 204 in San Antonio and 210 in Mexico City. Seven field standard stereophotographs of each eye were obtained, adapting the Early Treatment Diabetic Retinopathy Study protocol, and graded at the Fundus Photograph Reading Center of the University of Wisconsin.
  
  
  RESULTS
  Early nonproliferative DR occurred in 37 (17.6%) and 39 (19.1%) patients in Mexico City and San Antonio, respectively. Moderate-to-severe nonproliferative DR occurred in 55 (26.2%) and 37 (18.1%) patients in Mexico City and San Antonio, respectively, and proliferative DR occurred in 12 (5.7%) and 7 (3.4%) patients in Mexico City and San Antonio, respectively. Using univariate and multivariate logistic regression analysis with DR as the dependent variable, age, duration of disease, and fasting glucose concentration were positively and significantly associated with retinopathy, whereas city, systolic blood pressure, and other selected metabolic variables were not. We defined moderate-to-severe DR to include the categories of moderate-to-severe nonproliferative and proliferative DR. For this combined category, Mexico City patients with diabetes had a significantly higher prevalence (P < 0.01) than those from San Antonio when analyzed by multiple logistic regression analysis (odds ratio for Mexico City/San Antonio, 1.72; 95% CI 1.10-2.70).
  
  
  CONCLUSIONS
  Overall prevalence of DR is similar in both cities. However, moderate-to-severe DR is significantly higher in Mexico City.
authors.affiliation: Centro de Estudios en Diabetes, México. cgonzala@buzon.main.conacyt.mx
authors.forename: M E
authors.initials: ME
authors.lastname: González Villalpando
authors.forename: C
authors.initials: C
authors.lastname: González Villalpando
authors.forename: B
authors.initials: B
authors.lastname: Arredondo Pérez
authors.forename: S V
authors.initials: SV
authors.lastname: Martínez Díaz
authors.forename: B
authors.initials: B
authors.lastname: Mitchell
authors.forename: D
authors.initials: D
authors.lastname: Rivera Martínez
authors.forename: R
authors.initials: R
authors.lastname: Klein
authors.forename: S M
authors.initials: SM
authors.lastname: Haffner
authors.forename: M P
authors.initials: MP
authors.lastname: Stern
mesh_terms: D000328:Adult; D000367:Age Factors; D000704:Analysis of Variance; D001786:Blood Glucose / Q000032:analysis; D001794:Blood Pressure; D002784:Cholesterol / Q000097:blood; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology / Q000503:physiopathology*; D003930:Diabetic Retinopathy / Q000453:epidemiology* / Q000503:physiopathology*; D005215:Fasting; D005260:Female; D006801:Humans; D008297:Male; D008800:Mexico / Q000453:epidemiology; D008875:Middle Aged; D015999:Multivariate Analysis; D015995:Prevalence; D012044:Regression Analysis; D012720:Severity of Illness Index; D012959:Socioeconomic Factors; D013781:Texas / Q000453:epidemiology; D014280:Triglycerides / Q000097:blood; D014505:Urban Population
chemical_list: D001786:Blood Glucose; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D014280:Triglycerides; D002784:Cholesterol