title: Plasma homocysteine levels are associated with macular thickness in type 2 diabetes without diabetic macular edema.
abstract: OBJECTIVE
  To explore the relationships between macular thickness and the plasma concentrations of homocysteine, vitamin B12, folate, and other known risk factors for patients with diabetes without diabetic macular edema (DME).
  
  
  METHODS
  Fasting venous blood samples were collected from 252 subjects (126 relatively healthy subjects with type 2 diabetes without diabetic macular edema and 126 age- and gender-matched controls). Measurement of macular thickness and volume was performed for those subjects using SD-OCT. The plasma concentrations of homocysteine, vitamin B12, folate, and other known risk factors were analyzed in all the patients and controls using multiple linear regression models.
  
  
  RESULTS
  An increase in the serum levels of homocysteine was present within patients with type 2 diabetes compared to healthy individuals. The mean total plasma homocysteine levels were associated with a greater central subfield macular thickness (CSMT), average macular thickness (AMT), and average macular volume (AMV) in patients with type 2 diabetes without DME, after adjusting for age, sex, duration of diabetes, and HbA1c. Each 1 mmol/L increase in tHcy level was associated with a 6.57 µm greater CSMT (95% confidence interval [CI] 1.78, 11.36), a 4.51 µm greater AMT (95% CI 1.05, 7.98), and a 4.72 mm3greater AMV (95% CI 1.23, 8.21).
  
  
  CONCLUSIONS
  Higher homocysteine levels were associated with an increased CSMT, AMT, and AMV in diabetic patients without DME. This link may indicate that patients with type 2 diabetes with increased levels of plasma tHcy are more prone to develop a clinical manifestation of DME.
authors.affiliation: Tianjin Eye Hospital, Tianjin Key Laboratory of Ophthalmology and Vision Science, Clinical College of Ophthalmology, Tianjin Medical University, 4, Gansu Road, Heping District, Tianjin, 300020, People's Republic of China.
authors.forename: Ning
authors.initials: N
authors.lastname: Dong
authors.affiliation: Department of Ophthalmology, Beijing Shijitan Hospital, Capital Medical University, Beijing, People's Republic of China.
authors.forename: Hong
authors.initials: H
authors.lastname: Shi
authors.affiliation: Tianjin Eye Hospital, Tianjin Key Laboratory of Ophthalmology and Vision Science, Clinical College of Ophthalmology, Tianjin Medical University, 4, Gansu Road, Heping District, Tianjin, 300020, People's Republic of China. eye_tangxin@163.com.
authors.forename: Xin
authors.initials: X
authors.lastname: Tang
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000473:pathology; D005260:Female; D005492:Folic Acid / Q000097:blood; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D008266:Macula Lutea / Q000473:pathology*; D008269:Macular Edema / Q000209:etiology; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D014805:Vitamin B 12 / Q000097:blood
chemical_list: D015415:Biomarkers; D006710:Homocysteine; D005492:Folic Acid; D014805:Vitamin B 12
keywords: Biomarkers; Diabetes; Diabetic macular edema; Diabetic retinopathy; Homocysteine