Purpose. To analyze changes in the low-frequency part of the spectrum of the laser Doppler
fl owmetry (LDF) signal in patients with diabetic microangiopathy and to identify their correlations
with glomerular fi ltration rate.
Materials and methods. The study included 42 patients (20 men and 22 women) with type 2 diabetes
mellitus and diabetic foot syndrome, aged 58–77 years, with chronic kidney disease of the stage C3–
C4. Each patient performed the LDF registration followed by spectral analysis and assessment of its
indicators with the estimated glomerular fi ltration rate. The features of microcirculation disorders
were revealed on the base of it.
Results. There were no signifi cant correlations between the glomerular fi ltration rate and the
amplitudes of myogenic and neurogenic fl ux motions (p>0.05). However, there was a signifi cant
positive correlation between the contribution of myogenic fl ux motions to the low-frequency range
and glomerular fi ltration rate; and a negative one – for the contribution of neurogenic fl ux motions
(p<0.05). In six observations, there was a tendency to decrease of the amplitude of endothelial fl ux
motions as the glomerular fi ltration rate decreased.
Conclusion. In the course of this study, a new technique for assessing the contribution of the lowfrequency range components was tested. In patients with chronic kidney disease of the C3–C4
stage, decrease of the glomerular fi ltration rate correlated with the decrease of the contribution
of myogenic fl ux motions and increase of the contribution of neurogenic fl ux motions to the total
power of the low-frequency part of the amplitude-frequency spectrum of the LDF signal. These
changes can be explained by damage to the smooth muscle layer of the wall of arterioles and
venules with damage to pacemaker myocytes and violation of the basal vascular tone.
Keywords: laser Doppler fl owmetry, type 2 diabetes mellitus, microcirculation, diabetic
nephropathy, chronic kidney disease.