Elsevier

Metabolism

Volume 56, Issue 7, July 2007, Pages 992-997
Metabolism

Estimation of truncal adiposity using waist circumference or the sum of trunk skinfolds: a pilot study for insulin resistance screening in hirsute patients with or without polycystic ovary syndrome

Presented in part as a poster at the 88th Annual Meeting of the Endocrine Society, Boston, MA, June 2006.
https://doi.org/10.1016/j.metabol.2007.03.006Get rights and content

Abstract

Insulin resistance (IR) is an independent risk factor for cardiovascular disease and is a prevalent metabolic disturbance among women with polycystic ovary syndrome (PCOS). Central adiposity, a marker of IR and an accurate anthropometric method to estimate truncal adiposity, may represent a key clinical tool for IR screening in subpopulations at higher metabolic and cardiovascular risk, such as women with PCOS. The aims of the present study were (1) to investigate the influence of androgens on IR and central obesity in overweight or obese hirsute women with or without PCOS and (2) to test the reliability of the sum of trunk skinfolds (subscapular, suprailiac, and abdominal) to estimate truncal adiposity. This observational, cross-sectional study included 37 hirsute patients with body mass index of 25 kg/m2 or greater and aged between 14 and 41 years. Twenty-four had PCOS, and 13 had ovulatory cycles, normal androgen levels, and isolated hirsutism, named idiopathic hirsutism (IH). Nutritional, anthropometric, clinical, and laboratory evaluations were performed. Body composition was assessed by measurement of waist circumference and skinfold thickness and by dual-energy x-ray absorptiometry (DXA). Both groups presented similar ages, body mass index, and hirsutism score. The PCOS group had higher androgen levels, homeostasis model assessment (HOMA) index, and fasting insulin levels. Free androgen index was positively associated with HOMA, independent of truncal adiposity (r = 0.441, P = .009). Strong correlations were also observed between truncal adiposity measured by DXA and both the sum of trunk skinfolds (r = 0.863, P = .0001) and waist circumference in hirsute patients (r = 0.947, P = .0001). In our study, IR (HOMA index ≥3.8) was associated with truncal obesity, with a more androgenic profile, and with an unfavorable lipid profile. In conclusion, hirsutism per se appears not to be a risk for IR and related cardiovascular disease unless there is presence of central adiposity and/or abnormal androgen profile as observed in patients with PCOS. Waist circumference and the sum of trunk skinfolds represent accurate methods to estimate truncal adiposity, but waist circumference measurement seems to be the simplest method of clinical screening for IR in hirsute women.

Introduction

Obesity, a major public health concern, is a chronic disorder that results from the interaction of numerous social, physiologic, metabolic, and cellular factors [1]. This multifactorial illness is a risk factor for type 2 diabetes mellitus, cardiovascular disease, osteoarthritis, several types of cancer, and certain reproductive and metabolic disorders. It is generally accepted that this risk relates more to the central distribution of fat than to the total amount of body fat [2], [3], [4]. Abdominal obesity is thought to play an important role in insulin resistance (IR) because the increased production of free fatty acids may interfere with the action of insulin [5].

There is strong epidemiologic and clinical evidence [2], [6], [7] that sex steroid hormones greatly influence the regulation of adipose tissue distribution. Androgens may also affect central obesity in women during their reproductive years. The hyperandrogenism that is often seen in patients with polycystic ovary syndrome (PCOS) is associated with obesity of the abdominal phenotype [8], [9], [10], [11]. Hirsutism (excessive hair growth in women in places in which terminal hair is normally not found), one of the major symptoms of PCOS, may result from an overproduction of androgens by the ovaries and/or adrenal glands or by increased sensitivity of the pilosebaceous unit to normal levels of circulating androgens [8], [12], [13]. Thus, overweight and obese hirsute patients with normal or increased androgen levels may serve as a reliable model to assess the relationship of androgens and IR with central adiposity.

Measuring body fat is still a challenge for researchers and clinicians. Fat depots are mainly subcutaneous and intra-abdominal; however, considerable amounts of fat can also reside among and inside muscles, particularly in the elderly [14]. Because fat is widespread and inaccessible, it is not possible to directly and accurately measure whole-body adiposity. Measurement of the waist-hip ratio (WHR) has been shown to reflect the amount of abdominal fat and is widely used to investigate the relations between abdominal fat and metabolic profile [15]. More recently, waist circumference alone has been reported to be more closely correlated with the amount of abdominal fat than with WHR in men and women [16], [17], [18]. Finally, the body mass index (BMI) is the main tool to evaluate total body adiposity. However, studies have shown that a large amount of visceral fat may represent a cardiovascular risk factor even within normal BMI values [5], [18]. Actually, it seems to be better to consider the combined BMI and waist circumference for estimating cardiovascular risk [19].

Currently, the most accurate in vivo method of measuring abdominal adipose tissue is computed tomography (CT). Although CT represents a technological advance and is used as a reference standard, its application in routine clinical practice and research is limited by cost, availability of equipment, and exposure to significant amounts of ionizing radiation [20]. Other techniques that are comparable to CT in terms of accuracy include magnetic resonance imaging [16] and dual-energy x-ray absorptiometry (DXA), a simple method that exposes subjects to minimal amounts of radiation [16], [20]. In addition, one of the simplest methods to evaluate total body fat is the measurement of skinfold thickness [21]. However, there is a dearth of studies evaluating the use of specific skinfolds to determine truncal obesity [22], [23]. Therefore, the aims of the present study were (1) to investigate the influence of androgens on IR and central obesity in overweight or obese hirsute women with or without PCOS and (2) to test the reliability of the sum of trunk skinfolds (subscapular, suprailiac, and abdominal) to estimate truncal adiposity.

Section snippets

Patients

The study population included women consulting for hirsutism at the Gynecological Endocrinology Unit at Hospital de Clínicas de Porto Alegre, Brazil. Late-onset (nonclassical) congenital adrenal hyperplasia, Cushing syndrome, and androgen-secreting tumors were excluded by appropriate tests as previously described [8], [24], [25]. Patients with diabetes mellitus and hyperprolactinemia (serum prolactin concentrations >20 μg/L on 2 different occasions) were also excluded.

Thirty-seven hirsute

Results

The clinical and anthropometric characteristics of hirsute patients with PCOS or IH are summarized in Table 1. The 2 groups were similar in terms of age, severity of hirsutism, and blood pressure, but WHR was higher in the group with PCOS. Patients with IR constituted 67% of the PCOS group and 30% of the group with IH. Ten patients had impaired glucose tolerance (7 in the group with PCOS and 3 in the group with IH).

Table 2 shows hormonal and metabolic data of hirsute patients. As expected, the

Discussion

In the present study, hirsute patients with PCOS had a higher percentage of truncal adiposity, greater testosterone levels, and free androgen index than women of similar age and degree of hirsutism without PCOS. Moreover, a positive correlation was found between HOMA index and androgens, independent of central adiposity, indicating that hyperandrogenism in PCOS may be additive to elevated waist circumference in increasing risk of IR and seems to be an independent predictor of IR. These findings

Acknowledgment

This study was supported by grants from Conselho Nacional de Desenvolvimento Científico e Tecnológico and PRONEX 26/98 (Programa de Apoio aos Núcleos de Excelência em Pesquisa).

References (43)

  • National Institutes of Health et al.

    Clinical guidelines on the identification, evaluation and treatment of overweight and obesity in adults. The evidence report

    (1998)
  • World Health Organization

    Obesity: preventing and managing the global epidemic. Report of WHO consultation

    (1998)
  • J.P. Després et al.

    Treatment of obesity: need to focus on high risk abdominally obese patients

    Clin Rev

    (2001)
  • O. Bosello et al.

    Visceral obesity and metabolic syndrome

    Obes Rev

    (2000)
  • J.S. Mayes et al.

    Direct effects of sex steroid hormones on adipose tissues and obesity

    Obes Rev

    (2004)
  • G.B. Donato et al.

    Menopausal status is associated with central adiposity measured at different cut-offs of waist circumference and waist-to-hip ratio

    Menopause

    (2006)
  • P.M. Spritzer et al.

    Leptin concentrations in hirsute women with polycystic ovary syndrome or idiopathic hirsutism: influence on LH and relationship with hormonal, metabolic, and anthropometric measurements

    Hum Reprod

    (2001)
  • D.A. Ehrmann

    Polycystic ovary syndrome

    N Engl J Med

    (2005)
  • I. Ek et al.

    A unique defect in the regulation of visceral fat cell lipolysis in the polycystic ovary syndrome as an early link to insulin resistance

    Diabetes

    (2002)
  • J.J. Puder et al.

    Central fat excess in polycystic ovary syndrome: relation to low-grade inflammation and insulin resistance

    J Clin Endocrinol Metab

    (2005)
  • R.L. Rosenfield

    Hirsutism

    N Engl J Med

    (2005)
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