Macro- and microcirculation in the lower extremities--possible relationship.

Aims: Impaired blood supply is a significant risk factor for diabetic foot ulceration and gangrene. A possible relationship between peripheral macroangiopathy and the spectral components of microvascular skin blood flow in the lower extremities was tested in diabetic patients (DP) and non-diabetic subjects (C).

Patients And Methods: Basal skin blood flow (BSBF) was recorded for 30min at the right and left medial malleolus (predominantly nutritive capillary circulation) by laser Doppler flowmetry in 64 DP and 31 C. Its oscillatory components were analyzed using wavelet transform. Peripheral arterial obliterative disease (PAOD) was defined according to ankle/brachial index (ABI): PAOD+ (ABI<0.9: 21 DP, 12 C), PAOD- (ABI 0.91-1.3: 43 DP, 19 C).

Results: No statistically significant differences in BSBF and its oscillatory components were observed between PAOD+ and PAOD-, neither in DP nor in C. In DP, the spectral component of microvascular flow associated with endothelial activity was in significant positive correlation with systolic pressures on brachial and dorsal pedal artery (p=0.001 and 0.010, respectively).

Conclusions: These results indicate that mean BSBF and its oscillatory components do not change with diabetic PAOD; however there is a strong correlation between systolic pressure and the oscillatory components of BSBF related to endothelial activity manifested in the frequency interval 0.0095-0.02Hz.