The capillary blood cell velocity (CBV) was measured using two different cross-correlation systems. Cross-correlation was performed by (1) a self-tracking, analogue cross-correlation technique and (2) by a new fully computerized system. The CBV was measured at rest and during venous occlusion and postocclusive reactive hyperemia (PRH) after 1-min arterial occlusion. The PRH response was described by determining the peak CBV. The correlations between the values obtained by the two systems were highly significant. CBV at rest: r = 0.97 (p < 0.001); CBV during venous occlusion: r = 0.97 (p < 0.001), peak CBV during PRH: r = 0.97 (p < 0.001). The stability of measurements with the computerized system was high. Only 0.08% of CBV variations was due to repeated measurements. This computerized system represents a reliable innovation which greatly facilitates CBV measurements, especially in clinical practice. The program includes automatic calculation of data (mean and maximum and minimum CBV, area under the curve, and integral, etc.).

Adolescent↗

PubMedDate not supplied

Patients with type 1 diabetes lack vasoconstrictor response in skin microcirculation during insulin-induced hypoglycemia.

Disturbed hemodynamic reactions to insulin-induced hypoglycemia have been documented in diabetic patients and considered related to hyperinsulinemia and impairment of autonomic nervous functions. In the present study we investigated the effect on skin microcirculation of insulin-induced hypoglycemia obtained during moderate hyperinsulinemia, in 7 men with type 1 diabetes and in 8 healthy age- and sex-matched controls. The patients had all normal cardiovascular reflexes as assessed by respiratory sinus arrhythmia and Valsalva ratio. The skin microcirculation of the left fourth finger nailfold was investigated by laser Doppler fluxmetry, and the skin temperature within the same area was measured by a thermistor. Hypoglycemia was induced by a constant insulin infusion of Actrapid Human, 0.034 U kg-1 h-1 during 120 min. Plasma adrenaline, noradrenaline and pancreatic polypeptide increased significantly in both groups during hypoglycemia and the insulin levels never exceeded 50 mUl-1. A close to identical arterial hypoglycemia was obtained in the two groups 60 min after onset of insulin infusion. During hypoglycemia the control subjects revealed a significant decrease in laser Doppler flux (p < 0.025), while it was unchanged in the diabetic patients. Simultaneously, the skin temperature decreased (p < 0.05) in the controls, but was unchanged in the diabetic patients. The present study indicates that type 1 diabetic patients with normal cardiovascular reflexes have an abolished vasoconstrictor response in skin microcirculation of fingers during insulin-induced hypoglycemia, despite the fact that neurogenic and neuroglucopenic symptoms developed in these patients during hypoglycemia.

Adult↗

PubMedDate not supplied

Spatial and temporal variation in laser Doppler flux values in healthy lower limbs: comparison between the standard and the multiprobe.

Skin flow recordings with a laser Doppler instrument have not proven useful for evaluation of patients with peripheral arterial occlusive disease. The introduction of a probe using seven fibers suggested a reduction in spatial variation, but few studies using this multiprobe have been published. The present study was designed to compare the multiprobe to the standard probe placed between the knee and the first toe, chosen to fit a future study for amputation levels. The aim was to evaluate the multiprobe for that purpose. A laser Doppler fluxmeter with a standard and a multiprobe was used. Measurements were made in five probe sites in lower limbs of healthy volunteers. Each subject was studied by 30-second recordings during 60 min with both probes. Statistically (p < 0.001) lower flux values were obtained with the multiprobe than with the standard probe. The flux variation between the five probe sites was significantly (p < 0.01) higher with the standard probe than with the multiprobe, but the temporal variation was similar with both probes. The results suggest that the spatial variation in widely separated probe sites is reduced with the multiprobe. The temporal variation was not found to be reduced.

Adult↗

PubMedDate not supplied

Discrepancy in skin capillary circulation between fingers and toes in patients with type 1 diabetes.

The aim of the present study was to investigate skin microcirculation in patients with diabetes to see if any differences in microvascular reactivity could be found between a skin area with low (fingers) or high risk (toes) of complications. Twelve male patients with type 1 diabetes were investigated, the age was 34.7 +/- 8.5 years, and diabetes duration 12.8 +/- 7.7 years (mean +/- SD). Twelve healthy male subjects served as controls. Capillary blood cell velocity (CBV) in the nailfolds of the great toe and left fourth finger was investigated with videophotometric capillaroscopy, and total skin microcirculation with laser Doppler fluxmetry (LDF). CBV and LDF were studied during rest, and following a 1-min arterial occlusion at the proximal phalanx of the digit. Skin temperature was similar in patients and controls. The diabetic patients showed normal CBV and LDF values in skin microcirculation of the fingers, while a reduced (p < 0.01) CBV was found during reactive hyperemia in the toes. The ratio between CBV and LDF was decreased (p < 0.01), indicating a maldistribution of blood between skin capillaries and subpapillary vessels in the toes of diabetic patients. These disturbances may be of importance for the development of foot complications in diabetic patients.

Adult↗