Adipose tissue has aberrant morphology and function in PCOS: enlarged adipocytes and low serum adiponectin, but not circulating sex steroids, are strongly associated with insulin resistance.

• Context: Comprehensive characterization of the adipose tissue in women with polycystic ovary syndrome (PCOS), over a wide range of body mass indices (BMIs), is lacking. Mechanisms behind insulin resistance in PCOS are unclear. Objective: To characterize the adipose tissue of women with PCOS and controls matched pair-wise for age and BMI, and to identify factors, among adipose tissue characteristics and serum sex steroids, that are associated with insulin sensitivity in PCOS. Design/Outcome Measures: Seventy-four PCOS women and 31 controls were included. BMI was 18-47 (PCOS) and 19-41 kg/m2 (controls). Anthropometric variables, volumes of subcutaneous/visceral adipose tissue (magnetic resonance imaging; MRI), and insulin sensitivity (clamp) were investigated. Adipose tissue biopsies were obtained to determine adipocyte size, lipoprotein lipase (LPL) activity, and macrophage density. Circulating testosterone, free testosterone, free 17β-estradiol, SHBG, glycerol, adiponectin, and serum amyloid A were measured/calculated. Results: Comparison of 31 pairs revealed lower insulin sensitivity, hyperandrogenemia, and higher free 17β-estradiol in PCOS. Abdominal adipose tissue volumes/distribution did not differ in the groups, but PCOS women had higher waist-to-hip ratio, enlarged adipocytes, reduced adiponectin, and lower LPL activity. In regression analysis, adipocyte size, adiponectin, and waist circumference were the factors most strongly associated with insulin sensitivity in PCOS (R2=0.681, P < 0.001). Conclusions: In PCOS, adipose tissue has aberrant morphology/function. Increased waist-to-hip ratio indicates abdominal/visceral fat accumulation, but this is not supported by MRI. Enlarged adipocytes and reduced serum adiponectin, together with a large waistline, rather than androgen excess, may be central factors in the pathogenesis/maintenance of insulin resistance in PCOS.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Endokrinologi och diabetes (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Endocrinology and Diabetes (hsv//eng)

Nyckelord

Adipocytes

pathology

Adiponectin

blood

Adipose Tissue

pathology

Adult

Amyloid

blood

Body Height

physiology

Body Mass Index

Body Weight

physiology

Cell Size

Female

Glycerol

blood

Gonadal Steroid Hormones

blood

Humans

Immunohistochemistry

Insulin Resistance

physiology

Lipoprotein Lipase

metabolism

Macrophages

pathology

Polycystic Ovary Syndrome

pathology

Sex Hormone-Binding Globulin

metabolism

Waist Circumference

Waist-Hip Ratio

blood

MEDICINE

Physical Chemistry

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)