Rs. Rittmaster et al., THE ROLE OF ADRENAL HYPERANDROGENISM, INSULIN RESISTANCE, AND OBESITYIN THE PATHOGENESIS OF POLYCYSTIC OVARIAN SYNDROME, The Journal of clinical endocrinology and metabolism, 76(5), 1993, pp. 1295-1300
Hyperandrogenism, insulin resistance, and obesity are common features
of polycystic ovarian syndrome (PCOS). This study was designed to inve
stigate the relationship among these factors and how they might contri
bute to ovulatory dysfunction in PCOS. Adrenal androgen secretion and
insulin resistance were quantified in oligomenorrheic women with PCOS
and in three groups of eumenorrheic women: weight-matched hirsute wome
n, obese nonhirsute women, and thin nonhirsute women. Adrenal androgen
secretion was defined as the androstenedione response to synthetic co
rticotropin. Insulin resistance was estimated by calculating the area
under the curve for serum insulin levels in response to a 75 g oral gl
ucose load. The mean serum androstenedione response (nmol/L) to cortic
otropin in PCOS (5.6 +/- 1.3) was greater than that in eumenorrheic hi
rsute women (3.4 +/- 0.5; P < 0.10), obese nonhirsute women (1.8 +/- 0
.8; P < 0.05), and lean nonhirsute women (1.9 +/- 0.5; P < 0.05). The
serum androstenedione response was not correlated with body mass index
(BMI). The area under the curve for serum insulin (mU/L . min/1000) i
n PCOS (29.1 +/- 5.3) was greater (P < 0.001) than in eumenorrheic hir
sute women (9.1 +/- 1.7), obese nonhirsute women (5.8 +/- 1.0), and le
an nonhirsute women (4.5 +/- 0.4). The serum insulin response was high
ly correlated with BMI (P < 0.001) in the three groups of obese women,
but women with PCOS became significantly more insulin resistant with
increasing BMI (P < 0.02). There was no correlation between adrenal an
drogen secretion and insulin resistance in any of the groups. We concl
ude that adrenal hyperandrogenism and insulin resistance are independe
nt predictors of anovulation in hirsute women. These conditions are pr
esent in both oligomenorrheic and eumenorrheic hirsute women, but are
present to a greater extent in anovulatory women. Obese women with PCO
S also differ from eumenorrheic controls by developing a greater degre
e of insulin resistance as body mass increases.