Dynamic nailfold videocapillaroscopy may be used for early detection of microvascular dysfunction in obesity

It has been hypothesized that obesity is the primary cause of microvascular dysfunction (MD), which could be a pathway to increase blood pressure and decrease insulin sensitivity. Due to the high prevalence of this metabolic disorder in the world today, the aim of this study was to investigate which is the most appropriate videocapillaroscopic method, between nailfold and dorsal finger, to assess microvascular function in obese patients since both techniques are non-invasive and could be used for early detection as well as for follow-up.

Eighteen lean [27.8±6.2years, body mass index (BMI) 21.8±1.8kg/m(2)] and nineteen obese (30.8±4.6years; BMI 32.3±1.5kg/m(2)) women participated in the study. Dynamic nailfold videocapillaroscopy assessed morphological (capillary diameters) and functional [functional capillary density (FCD); red blood cell velocity (RBCV) at baseline and peak and time (TRBCVmax) taken to reach it during the post-occlusive reactive hyperemia (PORH) response, after 1-min ischemia] parameters; while dorsal finger videocapillaroscopy assessed FCD at rest and capillary recruitment during PORH and post-venous occlusion.

RBCV (0.32±0.01 vs. 0.30±0.01mm/s; p<0.0001) and RBCVmax (0.32±0.01 vs. 0.30±0.015mm/s; p=0.0020) were significantly higher in control subjects compared to the obese group. Moreover, TRBCVmax was prolonged in the obese group compared to control one (3.5±1.4 vs. 5.5±1.3s; p=0.0001). Multiple regression analysis showed that these variables were influenced by some others, especially those related to adiposity and metabolic disease. On the other hand, dorsal finger videocapillaroscopy did not show any significant differences between groups.

Our results strongly suggest that microvascular dysfunction consequent to obesity could be better detected by dynamic nailfold videocapillaroscopy than by dorsal finger videocapillaroscopy.