Research

Hormonal

In women with PCOS, increasing adiposity (BMI) significantly blunts LH pulse amplitude and mean LH levels, rendering LH-based diagnosis unreliable in obese subjects (BMI ≥ 30 kg/m²), whereas LH pulse frequency remains elevated regardless of BMI.

If you have PCOS symptoms (like irregular periods or high androgens) but your LH levels look normal, do not assume you are free of PCOS if you are overweight. Obesity suppresses LH levels in PCOS patients, masking the typical hormonal signature. Diagnosis should rely on other criteria (ultrasound, androgens) rather than LH alone if your BMI is 30 or higher.

GoodQualifiesHIGH confidence
BMI, an indicator of relative adiposity, had a significant negative impact on 24-h mean LH pulse amplitude (r = -0.63, P < 0.001) and the peak increment of LH in response to GnRH stimulation (r = -0.41; P = 0.02) for PCOS but not NC women... 24-h LH levels failed to discriminate PCOS from NC women in 43% (6/14) of obese (BMI ≥ 30 kg/m2) PCOS women.
Amanda Arroyo et al. · The Journal of Clinical Endocrinology & Metabolism · 1997

Why this rating

Randomized controlled observational study with rigorous 24-hour pulsatile sampling and GnRH stimulation testing.

Source

Inappropriate Gonadotropin Secretion in Polycystic Ovary Syndrome: Influence of Adiposity<sup>1</sup>

Amanda Arroyo et al. · The Journal of Clinical Endocrinology & Metabolism · 1997

DOI 10.1210/jcem.82.11.4377

cross_sectional · n=65Cited 181×
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DOI resolved against Crossref · corpus check 2026-06-10

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