Oscillazioni del flusso microvascolare in pazienti obesi iperglicemici

Aim: The present study was aimed to investigate skin microvascular blood flow oscillations by noninvasively LDPM and to evaluate the effects of insulin resistance and hyperglycemia on skin perfusion in obese subjects. Furthermore, we assessed the effects of hypocaloric diet on skin microvascular blood flow in newly diagnosed hyperglicemic obese patients. Methods: Fifty-four normoglycemic (27 females) and fifty-four hyperglycemic (27 females) obese adults were recruited from our Outpatient Clinic and treated with hypocaloric diet for 6 months. Skin microvascular blood flow was recorded by laser Doppler flowmeter and blood flow oscillations were analyzed by wavelet transform. Moreover, reactive hyperemia, due to 2 min brachial artery occlusion, was investigated in fourteen normoglycemic (7 females) and sixteen hyperglycemic (8 females) obese adults. Results: Skin microvascular blood flow (9.4 ± 0.3 vs 11.8 ± 0.4 PU, p<0.01) and total power spectral density (PSD: 113.2 ± 10.1 vs 176.5 ± 11.4 PU2/Hz, p<0.01) were lower in the hyperglycemic than normoglycemic people. Among the frequency components of blood flow oscillations, myogenic activity spectral density was lower in hyperglycemic than normoglycemic patients (31.0 ± 0.7 vs 34.9 ± 0.7 %, p<0.01). Moreover, hyperglycemic subjects showed lower hyperemic response to artery occlusion compared to the corresponding one observed in normoglycemic patients. After 6 month hypocaloric diet, blood flow and spectral denisty significantly increased in hyperglycemic subjects. Myogenic activity-related oscillatory component spectral density was enhanced, while post-occlusive reactive hyperemia significantly improved. Conclusions: In conclusion, insulin resistance- and hyperglycemia-associated microvascular alterations severely affect peripheral resistance and tissue perfusion. Hypocaloric diet appeared to ameliorate arteriolar dilation and blood flow redistribution to tissue.