Acute Hyperglycemia Does Not Impair Microvascular Reactivity and Endothelial Function during Hyperinsulinemic Isoglycemic and Hyperglycemic Clamp in Type 1 Diabetic Patients

Table 1

Biochemical parameters, parameters of insulin sensitivity and microvascular reactivity during isoglycemic (ISO) and hyperglycemic (HYPER) hyperinsulinemic clamp and during the control test in Type 1 diabetic patients.

	Clamp (𝑛=16)			Control test (𝑛=14)
	Baseline	ISO	Hyper	Baseline	End
Glucose (mmol·L^−1)	6.8±2.7	6.5±1.9	12.0±1.6	6.9±2.2	6.9±1.8
Insulin (mIU·L^−1)	55±39	155±54^a	152±47^a	74±55	65±46
M (μmol/kg·min)	—	30±10	57±26	—	—
MCRG (mL/kg·min)	—	5.0±2.3	4.8±2.4	—	—
MCRG/L (mL/kg·min per mU/L ×100)	—	3.5±1.6	3.5±2.2	—	—
TC (mmol·L^−1)	4.6±0.7	—	4.3±0.6^b	4.7±0.8	4.3±0.8^b
HDL-C (mmol·L^−1)	1.3±0.4	—	1.2±0.4^b	1.3±0.4	1.2±0.3^b
LDL-C (mmol·L^−1)	2.9±0.6	—	2.7±0.5^b	2.9±0.6	2.7±0.6^b
TG (mmol·L^−1)	0.9±0.3	—	0.8±0.2	1.1±0.7	1.0±0.5
Fibrinogen (g· L^−1)	3.4±0.9	—	3.3±0.8	3.4±1.0	3.1±0.9^b
MDA (μmol·L^−1)	1.8±0.3	—	1.8±0.2	1.8±0.5	1.7±0.3
E-selectin (ng·mL^−1)	29±12	—	27±11^a	29±15	28±14^b
P-selectin (ng·mL^−1)	132±50	—	93±34^a	126±50	111±27
ICAM-1 (ng·mL^−1)	251±48	—	215±41^a	237±40	212±33^b
VCAM (ng·mL^−1)	812±183	—	673±117^a	815±203	665±165^a
PORHmax-fi (PU)	224±88	255±112	234±99	212±92	199±60
PORHtmax-fi (s)	24.7±22.1	15.4±11.2	19.1±12.2	19.4±20.3	28.3±27.8
PORHmax/t-fi (PU·s^−1)	8.3±11.8	9.3±12.6	4.5±4.4	6.7±7.7	13.1±20.5
PORHmax-fo (PU)	40±16	39±19	47±16^b	32±12	35±12
PORHtmax-fo (s)	13.5±5.1	6.1±4.7^a	10.4±8.4	11.8±6.0	11.3±9.0
PORHmax/t-fo (PU·s^−1)	2.6±1.5	11.2±14.9^c	10.4±16.5^c	2.7±2.4	3.7±3.0
THmax-fo (PU)	94±29	90±42	97±52	89±46	91±45
THtmax-fo (s)	70±13	77±16	69±15^x	70±16	64±19
THmax/t-fo (PU·s^−1)	1.3±0.5	1.2±0.7	1.4±0.8^x	1.3±1.0	1.7±1.6

Statistical significance of differences as compared to clamp and control test baseline values: ^a𝑃<0.001, ^b𝑃<0.01, ^c𝑃<0.05,and ^x𝑃<0.05 when comparing isoglycemic and hyperglycemic phase.
M: glucose disposal rate, MCR_G: metabolic clearance of glucose, MCR_G/I: insulin sensitivity index, TC: total cholesterol, HDL-C: HDL-cholesterol, LDL-C: LDL-cholesterol, TG: triglycerides, MDA: malonyl dialdehyde, ICAM-1: intercellular cell adhesion molecule 1, VCAM: vascular cell adhesion molecule, PORHmax-fi: maximal perfusion during postocclusive reactive hyperemia at fingertip, PORHtmax-fi: time to maximal perfusion during postocclusive reactive hyperemia at fingertip, PORHmax/t-fi: velocity of perfusion increase during post-occlusive reactive hyperemia at fingertip, PORHmax-fo: maximal perfusion during post-occlusive reactive hyperemia in forearm, PORHtmax-fo: time maximal perfusion during post-occlusive reactive hyperemia in forearm, PORHmax/t-fo: velocity of perfusion increase during post-occlusive reactive hyperemia in forearm, THmax-fo: maximal perfusion during thermal hyperemia, THtmax-fo: time to maximal perfusion during thermal hyperemia, and THmax/t-fo: velocity of perfusion increase during thermal hyperemia.