Hum. Reprod. Advance Access originally published online on September 25, 2007
Human Reproduction 2007 22(11):2974-2980; doi:10.1093/humrep/dem302
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Evidence of subpopulations with different levels of insulin resistance in women with polycystic ovary syndrome
1 Unidad de Reproducción y Desarrollo, Departamento de Ciencias Fisiológicas, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Alameda B. OHiggins 340, Santiago, Chile 2 Fundación Médica San Cristóbal, Luis Pasteur 5292, Vitacura, Santiago, Chile 3 Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Alameda B. OHiggins 340, Santiago, Chile
4 Correspondence address. Tel/Fax: +56-2-6862975; E-mail: pvigil{at}bio.puc.cl
BACKGROUND: Polycystic ovary syndrome (PCOS) is non-uniformly associated with insulin resistance (IR). We examined IR in women with PCOS.
METHODS: Sixty-nine PCOS women were subjected to the insulin suppression test (IST) to determine their steady-state plasma glucose (SSPG) as a direct measure of insulin sensitivity.
RESULTS: SSPG exhibited a multimodal distribution suggesting the existence of subpopulations. The heterogeneous distribution of plasma glucose at 180 min (P = 0.011), with three modes, suggested differences in the plasma glucose level trajectories during the IST. Hence, the population was separated into three groups: (i) (n = 33), subjects with SSPG
152.5 mg/dl, corresponding to the first to fifth deciles; (ii) (n = 29), subjects in the interval 152.5 mg/dl < SSPG
300 mg/dl; (iii) (n = 7), subjects with SSPG > 300 mg/dl, corresponding to the tenth decile. Plasma glucose distributions at 180 min showed differences in their mean values and ranges among groups (P < 0.0001). The trajectories of the groups differed significantly during the IST (P < 0.0001).
CONCLUSIONS: insulin sensitivity in our patients exhibited a discontinuous distribution, implying that PCOS is a heterogeneous disorder possessing subpopulations regarding IR.
Key words: hyperandrogenism/insulin resistance/insulin suppression test/polycystic ovary syndrome/subpopulations
Submitted on April 10, 2007; resubmitted on August 6, 2007; accepted on August 24, 2007.