Table 1

Characteristics of participating patients and matched healthy subjects and parameter changes in diabetic patients during euglycemic clamp

Healthy subjects (n = 20)P value (between groups)Diabetic patients (n = 20)P value (change from baseline)
Before clampDuring clamp
Age (years)33 ± 734 ± 6
Sex (male/female)12/812/8
A1C (%)6.9 ± 0.4
Blood glucose (mmol/l)4.5 ± 0.5<0.0019.3 ± 1.7*5.3 ± 0.5<0.001
Insulin (pmol/l)319 ± 49<0.001104 ± 41*1,155 ± 278<0.001
C-Peptide (nmol/l)2.4 ± 0.4<0.0010.002 ± 0.002*
Systolic blood pressure (mmHg)119 ± 100.024126 ± 7*127 ± 70.447
Diastolic blood pressure (mmHg)61 ± 8<0.00172 ± 7*72 ± 70.899
Mean arterial pressure (mmHg)81 ± 8<0.00190 ± 6*90 ± 60.651
Pulse rate (bpm)62 ± 90.07767 ± 766 ± 80.091
Mean retinal vein diameter (μm)124 ± 100.054131 ± 12132 ± 120.152
Total retinal vein diameter (μm)537 ± 560.062573 ± 60578 ± 690.122
Mean venous blood velocity (cm/s)1.21 ± 0.140.1061.30 ± 0.191.17 ± 0.17< 0.001
Total volumetric blood flow (μl/min)43 ± 120.03553 ± 16*49 ± 150.0003
  • Data are means ± SD, except for sex (n).

  • *Significant difference between the two groups at baseline (unpaired t test).

  • †Significant changes during glucose clamp in diabetic patients (repeated-measures ANOVA). P < 0.05 was considered the level of significance.