Utility of nailfold capillaroscopy in the assessment of microvascular alterations in diabetes mellitus and its correlation with diabetic retinopathy: a cross-sectional comparative study

Abstract Background Type 2 diabetes mellitus (T2DM) is a prevalent metabolic disorder characterized by persistent hyperglycemia. It affects the microvasculature causing complications such as retinopathy, nephropathy, and neuropathy. Nailfold capillaroscopy (NFC) is an in vivo study of cutaneous microvascular circulation. Aim To study the nailfold capillaroscopic changes in patients of T2DM. Material and methods After approval from the ethics committee, a single-center hospital-based cross-sectional study was conducted at the outpatient clinic of the Department of Dermatology at a Tertiary care Hospital. One hundred T2DM cases and age-matched healthy controls were enrolled in the study between the ages of 20 and 60 years. Baseline fasting blood sugar (FBS), Hba1c, and fundoscopic examination for retinopathy were performed. T2DM patients were further divided into two groups: those without retinopathy (group A, n = 61) and those with retinopathy (group B, n = 39). Further subgroup analysis was done according to the disease duration and Hba1c levels within the diabetic patients. Group C consisted of individuals with a disease duration of less than 5 years which were compared to group D with a disease duration exceeding 5 years, whereas group E consisted of patients with Hba1c less than 7.0 which was compared to findings in group F with Hba1c more than 7.0. NFC was performed, and qualitative and quantitative parameters along with MDAD (morphology, diameter, architecture, and density) criteria were analyzed. Results Dilated capillaries, neoangiogenesis, meandering, tortuous capillaries, avascular zones, visibility of subpapillary venous plexus, and receding capillaries were significantly higher in T2DM individuals. The mean capillary density of T2DM individuals was 6.70 ± 0.76 which was significantly lower ( p ≤ 0.001) than healthy controls which was 7.01 ± 0.77. Patients with retinopathy had a significantly higher frequency of receding capillaries when compared to individuals without retinopathy. Conclusion The NFC changes correlated with microvascular alterations in T2DM patients, possibly helping in the non-invasive identification of T2DM individuals. Capillaroscopic alterations were not significant in differentiating between the retinopathy and non-retinopathy groups. The same stands true for the effect of duration and glycemic load in diabetic patients.