Περίληψη:
The aim of the present study was to examine the relationship among water
diuresis-induced changes in renal oxygenation, endothelial function, and
various metabolic parameters in type 2 diabetic patients and healthy
subjects at risk of type 2 diabetes. Thirty-eight subjects with type 2
diabetes (D: age, 54 +/- 10 years, mean +/- SD, 24 men) and 7 healthy
subjects with parental history of type 2 diabetes or with impaired
glucose tolerance (IGT) (relatives [R]: age 46 +/- 11 years, 4 men)
were included. Laser Doppler imaging scanning was used to measure
vasodilatation in the forearm skin in response to iontophoresis of 1%
acetylcholine (Ach) and 1% sodium nitroprusside (SNP), and ultrasound
was used to measure the flow-mediated dilation (FMD) and
nitroglycerin-induced dilation (NID) in the brachial artery. Renal
oxygenation was assessed by magnetic resonance imaging (MRI) before and
during water diuresis. A decrease in the magnetic parameter R2*
implies an increase in oxygenation. Renal medullary oxygenation did not
improve with diuresis in either group (D: -0.5 +/- 1.9, R: -0.4 +/- 2.1,
P = not significant [NS]). The renal cortical oxygenation showed a
small, but statistically significant, improvement after diuresis in the
2 groups (D: -0.6 +/- 1.1, R: -0.5 +/- 0.5, P < .05). There were no
correlations between the change in cortical R2* (R2* post-minus
R2* prewater diuresis) and the micro- and macrovascular reactivity.
The postdiuresis renal cortical R2* was negatively correlated with
both the Ach- and SNP-induced skin vasodilation (% change over
baseline)(r = -.40, P < .01 and r = -.39, P < .05, respectively), while
no correlation existed with the FMD and NID. The baseline renal cortical
oxygenation was also negatively correlated with the SNP-induced skin
vasodilation (r = .36, P < .05) and positively correlated with the
fasting plasma glucose, total cholesterol, and vascular cell adhesion
molecule (VCAM) concentrations (r = .34, P < .05, r = .31, P < .05 and r
= .37, P < .05, respectively). These preliminary findings suggest an
association between the kidney cortical oxygenation and the skin
microvascular reactivity, glycemia, and lipidemia. Water diuresis failed
to produce an improvement in renal medullary oxygenation in both
patients with diabetes and subjects at risk for diabetes. (C) 2004
Elsevier Inc. All rights reserved.
Συγγραφείς:
Economides, PA
Caselli, A
Zuo, CS
Sparks, C
Khaodhiar, L
and Katsilambros, N
Horton, ES
Veves, A
