title: Association between diabetic foot ulcer and diabetic retinopathy.
abstract: OBJECTIVE
  We aimed to investigate the prevalence of diabetic retinopathy (DR) in patients with diabetic foot ulcer (DFU) and elucidate the association between DR and DFU severities and their shared risk factors.
  
  
  METHODS
  A retrospective review was conducted on DFU patients who underwent ophthalmic and vascular examinations within 6 months; 100 type 2 diabetic patients with DFU were included. The medical records of 2496 type 2 diabetic patients without DFU served as control data. DR prevalence and severity were assessed in DFU patients. DFU patients were compared with the control group regarding each clinical variable. Additionally, DFU patients were divided into two groups according to DR severity and compared.
  
  
  RESULTS
  Out of 100 DFU patients, 90 patients (90%) had DR and 55 (55%) had proliferative DR (PDR). There was no significant association between DR and DFU severities (R = 0.034, p = 0.734). A multivariable analysis comparing type 2 diabetic patients with and without DFUs showed that the presence of DR [OR, 226.12; 95% confidence interval (CI), 58.07-880.49; p < 0.001] and proliferative DR [OR, 306.27; 95% CI, 64.35-1457.80; p < 0.001), higher HbA1c (%, OR, 1.97, 95% CI, 1.46-2.67; p < 0.001), higher serum creatinine (mg/dL, OR, 1.62, 95% CI, 1.06-2.50; p = 0.027), older age (years, OR, 1.12; 95% CI, 1.06-1.17; p < 0.001), higher pulse pressure (mmHg, OR, 1.03; 95% CI, 1.00-1.06; p = 0.025), lower cholesterol (mg/dL, OR, 0.94; 95% CI, 0.92-0.97; p < 0.001), lower BMI (kg/m2, OR, 0.87, 95% CI, 0.75-1.00; p = 0.044) and lower hematocrit (%, OR, 0.80, 95% CI, 0.74-0.87; p < 0.001) were associated with DFUs. In a subgroup analysis of DFU patients, the PDR group had a longer duration of diabetes mellitus, higher serum BUN, and higher serum creatinine than the non-PDR group. In the multivariable analysis, only higher serum creatinine was associated with PDR in DFU patients (OR, 1.37; 95% CI, 1.05-1.78; p = 0.021).
  
  
  CONCLUSIONS
  Diabetic retinopathy is prevalent in patients with DFU and about half of DFU patients had PDR. No significant association was found in terms of the severity of these two diabetic complications. To prevent blindness, patients with DFU, and especially those with high serum creatinine, should undergo retinal examinations for timely PDR diagnosis and management.
authors.affiliation: Department of Ophthalmology, Seoul National University Bundang Hospital, Seongnam, Korea.|Department of Ophthalmology, HanGil Eye Hospital, Incheon, Korea.
authors.forename: Duck Jin
authors.initials: DJ
authors.lastname: Hwang
authors.affiliation: Department of Orthopedic Surgery, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Kyoung Min
authors.initials: KM
authors.lastname: Lee
authors.affiliation: Department of Orthopedic Surgery, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Moon Seok
authors.initials: MS
authors.lastname: Park
authors.affiliation: Department of Endocrinology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Sung Hee
authors.initials: SH
authors.lastname: Choi
authors.affiliation: Department of Internal Medicine, Kangwon National University Hospital, Chuncheon, Korea.
authors.forename: Ji In
authors.initials: JI
authors.lastname: Park
authors.affiliation: Department of Ophthalmology, Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea.
authors.forename: Joon Hee
authors.initials: JH
authors.lastname: Cho
authors.affiliation: Department of Ophthalmology, Seoul National University Bundang Hospital, Seongnam, Korea.|Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Kyu Hyung
authors.initials: KH
authors.lastname: Park
authors.affiliation: Department of Ophthalmology, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Se Joon
authors.identifier: http://orcid.org/0000-0003-3692-7169
authors.initials: SJ
authors.lastname: Woo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D055109:Ankle Brachial Index; D017719:Diabetic Foot / Q000150:complications*; D003930:Diabetic Retinopathy / Q000150:complications*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012189:Retrospective Studies; D012720:Severity of Illness Index