Microvascular skin blood flow following the ingestion of 75 g glucose in healthy individuals

It is expected that microvascular blood flow might be affected by blood glu cose, blood insulin and C-peptide levels. In our investigation skin microva scular blood flow (LDF) was measured using laser doppler fluxometry at skin temperatures of 37 degrees C and 44 degrees C during a 75 g oral glucose l oad (OGT) or water in ten healthy volunteers (6 male, 4 female, age: 28.1 /- 4.0) who had fasted overnight. The transcutaneous oxygen tension (tcPo(2 )) was measured using a transcutaneous oxygen electrode at a temperature of 44 degrees C. The microvascular response to acetylcholine was investigated before the start of the ingestion period and after 30 minutes. In addition , the capillary blood cell velocity (CBV) was measured using dynamic capill aroscopy. During OGT an increase in LDF could be observed at 37 degrees C (180%, p < 0.005) but only a slight increase was observed at 44 degrees C (86%, n.s.). The microvascular response to acetylcholine increased by 164% (p < 0.05) a nd the TcPo2 values increased by 30% (p < 0.01) during the OGT investigatio n. No significant changes in the microvascular measurements could be observ ed during the water experiment. No significant changes could be observed in the CBV measurements in any phase of the investigation. Plasma C-peptide a nd insulin levels exhibited an association with the LDF measurements at 37 degrees C (r = 0.22, p < 0.05; r = 0.30, p < 0.05; respectively), whereas b lood sugar values showed an association with the TcPo2 measurements (r = 0. 39, p < 0.01). After the ingestion of glucose a sophisticated modulation of microvascular blood flow was found in healthy volunteers. Further studies are necessary t o investigate the role of a disturbed postprandial blood sugar control, ins ulin and C-peptide secretion in the development of microvascular dysfunctio n, especially in IDDM.