Obesity and insulin resistance but not hyperandrogenism mediates vascular dysfunction in women with polycystic ovary syndrome.
OBJECTIVE
Polycystic ovary syndrome (PCOS) is associated with biochemical evidence of early atherosclerosis; however, data regarding vascular function are controversial. We hypothesized that resistance vessel function (mediated by the endothelium or smooth muscle) would be impaired in women with PCOS and aimed to determine the contribution of hyperandrogenism, obesity, or insulin resistance to vascular dysfunction.


METHODS
Prospective study.


METHODS
University practice.


METHODS
Women with PCOS (n = 24) and age/weight-matched controls (n = 22).


METHODS
Vascular function was assessed by measuring forearm vasodilatation in response to both endothelium-dependent (acetylcholine/bradykinin) and endothelium-independent dilators (nitroprusside/verapamil).


METHODS
Resistance vessel function.


RESULTS
Forearm vasodilatation to all four drugs was reduced (>50%) in obese PCOS compared to lean PCOS subjects. There was no significant difference in vascular function between obese or lean women with PCOS compared to corresponding controls. Androgen levels did not correlate with vascular function. Stepwise regression analysis showed that body mass index (BMI) contributed maximally to vascular dysfunction (R(2) = 0.47).


CONCLUSIONS
This comprehensive study demonstrates for the first time that obese women with PCOS have markedly reduced vascular smooth muscle function compared to lean subjects with PCOS. In our study obesity and insulin resistance, but not hyperandrogenism, appeared to be significant modulators of vascular function.
Dokras
Anuja
A
Department of Obstetrics & Gynecology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52246, USA. anuja-dokras@uiowa.edu <anuja-dokras@uiowa.edu>
Jagasia
Dinesh H
DH
Maifeld
Michelle
M
Sinkey
Christine A
CA
VanVoorhis
Bradley J
BJ
Haynes
William G
WG
D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D006946:Hyperinsulinism / Q000503:physiopathology*; D007006:Hypogonadism / Q000503:physiopathology*; D007333:Insulin Resistance; D009765:Obesity; D011085:Polycystic Ovary Syndrome / Q000503:physiopathology*; D014652:Vascular Diseases / Q000503:physiopathology*; D014655:Vascular Resistance