May AMH levels distinguish LOCAH from PCOS among hirsute women?

[congenital adrenal hyperplasia]

To determine whether women with polycystic ovary syndrome (PCOS ) would be distinguishable from women with late onset congenital adrenal hyperplasia (LOCAH ) on the basis of antimullerian hormone (AMH ) levels .PCOS was diagnosed in 170 women ; 105 were polycystic ovary morphology (PCOM )+/oligo-anovulation (OA )+/hyperandrogenism (HA )+, 40 PCOM +/OA-/HA + and 25 PCOM-/OA +/HA +. These three groups were compared with 25 women in whom LOCAH was diagnosed .The mean serum AMH levels were 8 .12 ±1 .85 ng /ml in PCOM +/OA +/HA + group , 5 .34 ±1 .82 ng /ml in PCOM +/OA-/HA + group , 3 .02 ±1 .76 ng /ml in PCOM-/OA +/HA + group and 4 .43 ±1 .29 ng /ml in LOCAH group . The mean AMH level in PCOM +/OA +/HA + group was approximately twofold higher than the mean AMH level measured in LOCAH group (p <0 .001 ). Women with PCOM +/OA-/HA + had higher serum AMH levels than those with LOCAH , women with LOCAH had higher serum AMH levels than those with PCOM-/OA +/HA + but these differences were not statistically significant (p >0 .05 ).AMH is not suitable for distinguishing LOCAH from all types of hyperandrogenic patterns of PCOS , but is only applicable for a specific subtype , such as PCOS patients with three main diagnostic criteria . Therefore , ACTH stimulation test remains an essential clinical tool to diagnose LOCAH .