Regional and overall aortic function in nondiabetic individuals with insulin resistance and normal glucose tolerance.
BACKGROUND
Insulin resistance is associated with altered vascular function in diabetes.


OBJECTIVE
The objective of the study was to define the overall and regional aortic function as well as the changes of aortic function over time in nondiabetic individuals with insulin resistance and a normal oral glucose tolerance test (OGTT).


METHODS
This was a cross-sectional and longitudinal analysis with 12 months follow-up.


METHODS
The setting of the study was in primary care.


METHODS
Nondiabetic individuals (n = 181, mean age 42 ± 8 y) with a normal OGTT and insulin resistance as defined by the insulin sensitivity index (ISI) participated in the study.


METHODS
ISI was estimated from serial measurements of plasma insulin and glucose during an iv glucose tolerance test. Ascending and abdominal aortic distensibility (AoD) and stiffness index-β (AoSI) were assessed using echocardiography. Carotid-to-femoral artery pulse wave velocity (PWVc-f; an index of overall aortic function) was measured from carotid and femoral arteries Doppler flow velocities recorded simultaneously with an electrocardiogram. Associations between ISI, AoD, AoSI, and PWVc-f were assessed using linear regression analyses and ANOVA. Differences between baseline and 12 months were compared using a paired t test.


METHODS
AoD and AoSI associations as well as changes over a 12-month period in relation to ISI were measured.


RESULTS
Ascending AoD (P = .01) and ascending AoSI (P = .025) were significantly associated with ISI; in contrast, abdominal AoD and AoSI and PWVc-f did not. Changes in AoD, AoSI, and PWVc-f over time were more prominent in individuals with low ISI compared with those with high ISI.


CONCLUSIONS
The significant associations between ISI and aortic function suggest that insulin resistance may affect the cardiovascular system, even when OGTT is normal.
PhD, AssistantDemocritus University of Thrace, Dragana, 68100 Alexandroupolis, Greece. dstakos@med.duth.gr.
Dimitrios A
DA
Stakos
Konstantinos D
KD
Boudoulas
Trudy R
TR
Gaillard
Dara P
DP
Schuster
Kwame
K
Osei
Harisios
H
Boudoulas
D000328:Adult; D001741:Black or African American; D000818:Animals; D001011:Aorta / Q000378:metabolism / Q000503:physiopathology*; D001012:Aorta, Abdominal / Q000378:metabolism / Q000503:physiopathology*; D001786:Blood Glucose / Q000378:metabolism*; D002318:Cardiovascular Diseases / Q000208:ethnology / Q000378:metabolism / Q000503:physiopathology; D003430:Cross-Sectional Studies; D004548:Elasticity; D005260:Female; D005500:Follow-Up Studies; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000097:blood*; D007333:Insulin Resistance / Q000502:physiology*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D012307:Risk Factors
D001786:Blood Glucose; D007328:Insulin