Alterations in nonesterified free fatty acid trafficking rather than hyperandrogenism contribute to metabolic health in obese women with polycystic ovary syndrome.

To determine whether alterations in nonesterified fatty acid (NEFA) dynamics or degree of hyperandrogenism (HA) contribute to the difference in insulin sensitivity between women with metabolically healthy obese polycystic ovary syndrome (PCOS) (MHO-PCOS) and women with metabolically unhealthy obese PCOS (MUO-PCOS). Prospective cross-sectional study. Tertiary-care academic center. One hundred twenty-five obese women with PCOS. Consecutive obese (body mass index [BMI] ≥ 30 kg/m2) oligo-ovulatory women (n = 125) with PCOS underwent an oral glucose tolerance test and a subgroup of 16 participants underwent a modified frequently sampled intravenous glucose tolerance test to determine insulin-glucose and -NEFA dynamics. Degree of insulin resistance (IR) in adipose tissue (AT) basally (Adipo-IR) and dynamically (the nadir in NEFA levels observed [NEFAnadir], the time it took for NEFA levels to reach nadir [TIMEnadir], and the percent suppression in plasma NEFA levels from baseline to nadir [%NEFAsupp]); peak lipolysis rate (SNEFA) and peak rate of NEFA disposal from plasma pool (KNEFA); whole-body insulin-glucose interaction (acute response of insulin to glucose [AIRg], insulin sensitivity index [Si], glucose effectiveness [Sg], and disposition index [Di]); and HA (hirsutism score, total and free testosterone levels, and dehydroepiandrosterone sulfate levels). A total of 85 (68%) women were MUO-PCOS and 40 (32%) were MHO-PCOS using the homeostasis model of assessment of IR. Subjects with MUO-PCOS and MHO-PCOS did not differ in mean age, BMI, waist-to-hip ratio, HA, and lipoprotein levels. By a modified frequently sampled intravenous glucose tolerance test, eight women with MUO-PCOS had lesser Si, KNEFA, and the percent suppression in plasma NEFA levels from baseline to nadir (%NEFAsupp) and greater TIMEnadir, NEFAnadir, and baseline adipose tissue IR index (Adipo-IR) than eight subjects with MHO-PCOS, but similar fasting NEFA levels and SNEFA. Women with MUO-PCOS had a higher homeostasis model of assessment-β% and fasting insulin levels than women with MHO-PCOS. In bivalent analysis, Si correlated strongly and negatively with Adipo-IR and NEFAnadir, weakly and negatively with TIMEnadir, and positively with KNEFA and %NEFAsupp, in women with MUO-PCOS only. Independent of age and BMI, women with MUO-PCOS have reduced NEFA uptake and altered insulin-mediated NEFA suppression, but no difference in HA, compared with women with MHO-PCOS. Altered insulin-mediated NEFA suppression, rather than HA or lipolysis rate, contributes to variations in insulin sensitivity among obese women with PCOS.

Ezeh U ，Chen YI ，Pall M ，Buyalos RP ，Chan JL ，Pisarska MD ，Azziz R ... -  《-》

Adipocyte Insulin Resistance in PCOS: Relationship With GLUT-4 Expression and Whole-Body Glucose Disposal and β-Cell Function.

Impaired sensitivity to the antilipolytic action of insulin in adipose tissue (AT) may play a role in determining metabolic dysfunction in polycystic ovary syndrome (PCOS). To test the hypothesis that insulin resistance (IR) in AT is associated with whole-body insulin sensitivity and β-cell function in PCOS. Prospective cross-sectional study. Eighteen participants with PCOS and 18-matched control participants underwent a modified frequently sampled intravenous glucose tolerance test (mFSIVGTT); subgroups underwent single-slice computed tomography scans determining AT distribution and adipocyte glucose transporter type 4 (GLUT-4) expression. IR in AT in basal (by the adipose insulin resistance index [Adipo-IR]) and dynamic (mFSIVGTT-derived indices of insulin-mediated nonesterified fatty acids [NEFA] suppression [NEFAnadir, TIMEnadir, and %NEFAsupp]) states; whole-body insulin-mediated glucose uptake and insulin secretion in basal (by homeostatic model assessment [HOMA]-IR and HOMA-β%) and dynamic (mFSIVGTT-derived insulin sensitivity index [Si], acute insulin response to glucose [AIRg], and disposition index [Di]) states. Participants with PCOS had higher HOMA-IR and HOMA-β%, lower Si and Di, higher longer TIMEnadir, higher Adipo-IR and NEFAnadir, and a trend toward lower GLUT-4, than the control group participants. Adipo-IR was associated with dynamic state IR in AT (NEFAnadir TIMEnadir, and %NEFAsupp), but only in PCOS, and with HOMA-IR and HOMA-β% in both groups. NEFAnadir and TIMEnadir were negatively and %NEFAsupp positively associated with Si only in PCOS, but not with AIRg and Di, or GLUT-4 expression. Women with PCOS demonstrated increased IR in AT, which is closely associated with whole-body IR but not with dynamic state β-cell function or adipocyte GLUT-4 gene expression.

Ezeh U ，Chen IY ，Chen YH ，Azziz R ... -  《-》

Alterations in plasma non-esterified fatty acid (NEFA) kinetics and relationship with insulin resistance in polycystic ovary syndrome.

Ezeh U ，Arzumanyan Z ，Lizneva D ，Mathur R ，Chen YH ，Boston RC ，Chen YI ，Azziz R ... -  《-》

Metabolically Healthy Obesity (MHO) vs. Metabolically Unhealthy Obesity (MUO) Phenotypes in PCOS: Association with Endocrine-Metabolic Profile, Adherence to the Mediterranean Diet, and Body Composition.

Barrea L ，Muscogiuri G ，Pugliese G ，de Alteriis G ，Colao A ，Savastano S ... -  《Nutrients》

Menstrual dysfunction in polycystic ovary syndrome: association with dynamic state insulin resistance rather than hyperandrogenism.

To examine the relation of menstrual cyclicity abnormalities to hyperandrogenism (HA) and dynamic state insulin resistance (IR) in oligo-ovulatory women with polycystic ovary syndrome (PCOS). Prospective cross-sectional study. Tertiary-care academic center. Fifty-seven women with PCOS (1990 National Institutes of Health criteria) and 57 healthy control women matched by body mass index (BMI). Short insulin tolerance test (ITT). Menstrual cyclicity, sex hormone-binding globulin (SHBG), measures of HA (i.e., modified Ferriman-Gallwey score, total and free testosterone, dehydroepiandrosterone sulfate), and the rate constant for plasma glucose disappearance (kITT) derived from the short ITT. Adjusting for age, BMI, and ethnicity, the mean androgen measures were higher and SHBG trended lower, kITT was lower, and the prevalence of IR was higher in PCOS than in controls, independent of menstrual cyclicity. The optimal cutoff point for IR was set at kITT value of 3.57%/minute or lower. Overall, 79% of the women with PCOS had IR. To control further for the effect of ethnicity, a subgroup of 46 non-Hispanic white PCOS participants were studied; those who exhibited amenorrhea (n = 15) or oligomenorrhea (n = 19) had or tended toward having a lower kITT and a higher prevalence of IR than the women with PCOS and oligo-ovulatory eumenorrhea (n = 12). The kITT trended lower and the prevalence of IR trended higher in women with PCOS and amenorrhea than those with oligomenorrhea. The measures of SHBG and HA were similar across the three menstrual groups. Oligo-ovulatory women with PCOS and overt oligo/amenorrhea have greater degrees of IR but not HA when compared with oligo-ovulatory eumenorrheic women with PCOS, suggesting that IR and hyperinsulinemia but not HA play a role in determining the degree of menstrual dysfunction, which can be used as a clinical marker for the degree of IR in oligo-ovulatory PCOS.

Ezeh U ，Ezeh C ，Pisarska MD ，Azziz R ... -  《-》