Association of crossing capillaries in the finger nailfold with diabetic retinopathy in type 2 diabetes mellitus

AIMS/INTRODUCTION: Crossing capillaries in the finger nailfold might potentially be a novel diabetic retinopathy (DR) biomarker that could be assessed non‐invasively in the clinical setting. However, the association between crossing capillaries and DR is controversial. This study aimed to investigate the association between the percentage of crossing capillaries in the finger nailfold and DR in patients with type 2 diabetes mellitus. MATERIALS AND METHODS: This cross‐sectional study enrolled 108 type 2 diabetes mellitus patients (aged 40–75 years) who visited the outpatient diabetic clinic at Osaka University Hospital, Osaka, Japan, between May and October 2019. Capillary morphology was assessed using nailfold capillaroscopy based on the simple capillaroscopic definitions of the European League Against Rheumatism Study Group. Details of DR and other laboratory data were obtained from medical records. The association between the tertile of the percentage of the crossing capillary and DR was analyzed using multivariable logistic regression. RESULTS: After adjusting for age, sex, diabetes duration, glycated hemoglobin, systolic blood pressure, body mass index, and use of renin–angiotensin system inhibitor and antihyperlipidemic medication, the percentage of crossing capillaries was significantly associated with DR (multivariable‐adjusted odds ratios for increasing tertiles of the percentage of crossing capillary: 1 [reference], 2.05 [95% confidence interval 0.53–7.94], and 4.33 [95% confidence interval 1.16–16.21]; P‐trend = 0.028). CONCLUSIONS: A higher percentage of crossing capillaries in the nailfold was associated with a higher risk of DR, independent of traditional risk and inhibiting factors, in patients with type 2 diabetes mellitus.