Elevated serum thioredoxin-interacting protein in women with polycystic ovary syndrome is associated with insulin resistance

Authors

  • Jinlin Wu,

    1. Department of Endocrinology and Metabolism, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
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    • JL Wu and YJ Wu contributed equally to the work.
  • Yijia Wu,

    1. Reproductive Medical Center, Department of Gynaecology and Obstetrics, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
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    • JL Wu and YJ Wu contributed equally to the work.
  • Xuecui Zhang,

    1. Department of Endocrinology and Metabolism, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
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  • Shu Li,

    1. Department of Endocrinology and Metabolism, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
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  • Di Lu,

    1. Department of Endocrinology and Metabolism, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
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  • Shengbing Li,

    1. Department of Endocrinology and Metabolism, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
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  • Gangyi Yang,

    Corresponding author
    1. Department of Endocrinology and Metabolism, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
    • Correspondence: Dongfang Liu and Gangyi Yang, Department of Endocrinology and Metabolism, The Second Affiliated Hospital of Chongqing Medical University, 76 Linjiang Road, Yuzhong District, Chongqing 400010, China. Tel.: +86 186 23407751 and +86 23 68485216; Fax: +86 23 63693191 and +86 23 68486115; E-mails: ldf023023@yahoo.com.cn; gangyiyang@yahoo.com.cn

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  • Dongfang Liu

    Corresponding author
    1. Department of Endocrinology and Metabolism, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
    • Correspondence: Dongfang Liu and Gangyi Yang, Department of Endocrinology and Metabolism, The Second Affiliated Hospital of Chongqing Medical University, 76 Linjiang Road, Yuzhong District, Chongqing 400010, China. Tel.: +86 186 23407751 and +86 23 68485216; Fax: +86 23 63693191 and +86 23 68486115; E-mails: ldf023023@yahoo.com.cn; gangyiyang@yahoo.com.cn

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Summary

Objective

Women with polycystic ovary syndrome (PCOS) mostly have profound insulin resistance (IR) and β-cell dysfunction. Although thioredoxin-interacting protein (TXNIP) is a major regulator in IR and insulin secretion, no data on the plasma TXNIP level in patients with PCOS are available. This study aimed to determine the plasma TXNIP level and discuss the relationship between TXNIP and β-cell dysfunction/IR in patients with PCOS.

Patients

Eighty-three women with PCOS and 52 controls.

Measurements

Insulin sensitivity was expressed by M value obtained from euglycaemic–hyperinsulinaemic clamp. Homoeostatic model assessment for β-cell function (HOMA-β), △Ins30/△Glu30 and AUCins/glu were considered as the indices of fasting state, early-phase and total insulin secretion during oral glucose tolerance test, respectively. To evaluate β-cell function adjusted for insulin sensitivity, disposition index (DI) was used: basal DI (DI0), early-phase DI (DI30) and total DI (DI120). Plasma TXNIP levels were measured by enzyme-linked immunosorbent assay.

Design

Case-control study.

Results

Patients with PCOS had higher serum TXNIP, whereas lower M value, DI0, DI30 and DI120 than controls (< 0·05); their TXNIP correlated positively with weight, waist-to-hip ratio (WHR), body mass index (BMI), Ins0, Ins120 and HOMA-β and correlated negatively with M value and DI120 (< 0·05). Multiple stepwise regression analysis indicated that TXNIP remained associated with M value in PCOS subjects, after adjusting weight, BMI, WHR, HOMA-β, Ins0, Ins120 and DI120. However, no relationship between TXNIP and impaired β-cell function was found.

Conclusion

Serum TXNIP is elevated in women with PCOS and may be a contributing factor for IR.

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