***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Women with polycystic ovary syndrome ( PCOS ) are insulin resistant secondary to a postbinding defect in insulin signaling . Sequential euglycemic glucose clamp studies at 40 and 400 mU. m(-2 ) . min(-1 ) insulin doses with serial skeletal muscle biopsies were performed in PCOS and age- , weight- , and ethnicity-matched control women .  Steady-state insulin levels did not differ , but insulin-mediated glucose disposal was significantly decreased in PCOS women ( P < 0.05 ) . Insulin receptor substrate (IRS)-1-associated phosphatidylinositol 3-kinase ( PI 3 K ) activity was significantly decreased in PCOS ( n = 12 ) compared with control skeletal muscle ( n = 8 ; P < 0.05 ) . There was no significant difference in the abundance of IR , IRS-1 , or the p85 regulatory subunit of PI 3 K in PCOS ( n = 14 ) compared with control ( n = 12 ) muscle . The abundance of IRS-2 was significantly increased ( P < 0.05 ) in PCOS skeletal muscle , suggesting a compensatory change . We conclude that there is a physiologically relevant defect in insulin receptor signaling in PCOS that is independent of obesity and type 2 diabetes mellitus We performed this study to access the changes in glucose tolerance over time in a group of women with polycystic ovary syndrome ( PCOS ) ( n = 71 ) and control women ( n = 23 ) with regular menstrual cycles and baseline normal glucose tolerance . Mean follow-up was between 2 and 3 yr for both groups ( PCOS 2.5 + /- 1.7 yr ; controls 2.9 + /- 2.1 yr ) . Based on World Health Organization glucose tolerance categories , there was no significant difference in the prevalence of glucose intolerance at follow-up in the PCOS group . In the PCOS group , 25 ( 37 % ) had impaired glucose tolerance ( IGT ) and seven ( 10 % ) had type 2 diabetes mellitus at baseline , compared with 30 ( 45 % ) and 10 ( 15 % ) , respectively , at follow-up . There were also no differences within groups ( PCOS or control ) or between groups ( PCOS vs. control ) in the oral glucose tolerance test-derived measure of insulin sensitivity , but in the women with PCOS who converted to either IGT or type 2 diabetes mellitus , there was a significant decrease ( P < 0.0001 ) . At the follow-up visit , the mean glycohemoglobin level was 6.1 + /- 0.9 % in women with PCOS vs. 5.3 + /- 0.7 % in the control women ( P < 0.001 ) . Women with PCOS and baseline IGT had a low conversion risk of 6 % to type 2 diabetes over approximately 3 yr , or 2 % per year . The effect of PCOS , given normal glucose tolerance ( NGT ) at baseline , is more pronounced with 16 % conversion to IGT per year . Our study supports that women with PCOS ( especially with NGT ) should be periodically rescreened for diabetes due to worsening glucose intolerance over time , but this interval may be over several years and not annually STUDY QUESTION What is the prevalence of insulin resistance ( IR ) and the contributions of intrinsic and extrinsic IR in women diagnosed with polycystic ovary syndrome ( PCOS ) according to the Rotterdam criteria ? SUMMARY ANSWER We report novel clamp data in Rotterdam diagnosed PCOS women , using World Health Organization criteria for IR showing that women with PCOS have a high prevalence of IR , strengthening the evidence for an aetiological role of IR in both National Institutes of Health ( NIH ) and Rotterdam diagnosed PCOS in lean and overweight women . WHAT IS KNOWN ALREADY PCOS is a complex endocrine condition with a significant increased risk of gestational diabetes and type 2 diabetes . STUDY DESIGN , SIZE , DURATION Using a cross-sectional study design , 20 overweight and 20 lean PCOS ( Rotterdam criteria ) , 14 overweight and 19 lean body mass index ( BMI ) -matched control non-PCOS women underwent clinical measures of IR after a 3-month withdrawal of insulin sensitizers and the oral contraceptive pill . MATERIAL S , SETTING , METHODS In an academic clinic setting ,  glucose infusion rate ( GIR )  on euglycaemic-hyperinsulinaemic clamp was investigated as a marker of insulin sensitivity . MAIN RESULTS AND THE ROLE OF CHANCE PCOS women were more IR than BMI -matched controls ( main effect for BMI and PCOS ; P < 0.001 ) . IR was present in 75 % of lean PCOS , 62 % of overweight controls and 95 % of overweight PCOS . Lean controls ( mean ± SD ; GIR 339 ± 76 mg min⁻¹ m⁻² ) were less IR than lean PCOS ( 270 ± 66 mg min⁻¹ m⁻² ) , overweight controls ( 264 ± 66 mg min⁻¹ m⁻² ) and overweight PCOS ( 175 ± 96 mg min⁻¹ m⁻² ) . The negative relationship between BMI and IR reflected by GIR was more marked in PCOS ( y = 445.1 - 7.7x , R² = 0.42 ( P < 0.0001 ) than controls ( y = 435.5 - 4.6x , R² = 0.04 ( P < 0.01 ) ) . LIMITATIONS , REASONS FOR CAUTION The study did not use glucose tracer techniques to completely characterize the IR , as well as the lack of matching for body composition and age . WIDER IMPLICATION S OF THE FINDINGS IR is exacerbated by increased BMI , supporting intrinsic IR in PCOS . BMI impact on IR is greater in PCOS , than in controls , irrespective of visceral fat , prioritizing lifestyle intervention and the need for effective therapeutic interventions to address intrinsic IR and prevent diabetes in this high-risk population . STUDY FUNDING /COMPETING INTEREST(S ) This investigator-initiated trial was supported by grants from the National Health & Medical Research Council ( NHMRC ) Grant number 606553 ( H.J.T. , N.K.S. and S.K.H. ) as well as Monash University and The Jean Hailes Foundation . H.J.T. is an NHMRC Research Fellow . N.K.S. is supported through the Australian Government 's Collaborative Research Networks ( CRN ) programme . A.E.J. is a Jean Hailes and NHMRC scholarship holder . The authors declare that there is no conflict of interest associated with this manuscript Women with polycystic ovary syndrome ( PCOS ) often develop type 2 diabetes mellitus ( T2DM ) . To determine the magnitude of risk of developing T2DM among women with PCOS , development of T2DM was prospect ively assessed among women who had T2DM ( n = 97 ) and controls ( n = 95 ) using Kaplan-Meier survival analysis and Cox proportional hazards modeling . The women with T2DM had higher baseline weight ( body mass index , P < 0.01 ) and lower insulin sensitivity ( homeostasis assessment model of insulin resistance , P < 0.01 ) . The 8-year incidence rate among cases and controls was 13.4 % and 5.8 % , respectively ( relative risk = 2.3 ) . Obese cases had a fivefold risk of T2DM developing ( P < 0.01 ) compared with age-adjusted obese controls , indicating significant interaction between PCOS and obesity to effect T2DM risk In order to evaluate the acute insulin response after i.v . injection of glucagon in polycystic ovary syndrome ( PCOS ) , 35 women affected by PCOS and 11 normo-ovulatory controls underwent a 75 g oral glucose tolerance test ( OGTT ) and , 2 days later , a glucagon test ( 1 mg i.v . ) . Patients were analysed according to their degree of obesity ;  the insulin release after glucagon injection for lean PCOS subjects and control women was not statistically significantly different . Conversely obese PCOS patients had higher insulin secretion after both i.v . glucagon and OGTT when compared to the other groups . Moreover the insulin secretory patterns were heterogeneously represented in lean and obese PCOS women . When the patients were analysed according to their insulinaemic response to OGTT , normoinsulinaemic PCOS women and control subjects had a similar insulin response to i.v . glucagon whereas the hyperinsulinaemic PCOS group had a higher insulin response ( P < 0.0001 ) . Moreover , a highly significant relationship was found between the insulin response to OGTT and to glucagon administration in the PCOS population ( P < 0.0001 ; r = 0.73 ) , which was maintained also after controlling for obesity . Our results are consistent with the hypothesis that PCOS patients could have an insulin hyper-response to glucagon administration  , that is partially independent from obesity and related to their insulinaemic status . Moreover , the glucagon test could represent an effective alternative to OGTT in screening insulin disorders of PCOS patients ( at least in the absence of other risk factors ) , due to its reliability , simplicity , and speed of performance CONTEXT The polycystic ovary syndrome ( PCOS ) is the commonest endocrine abnormality in women of reproductive age . OBJECTIVE To determine the rate of hospital admissions for women with PCOS in Western Australian population in comparison to women without PCOS . DESIGN A population -based retrospective cohort study using data linkage in a statewide hospital morbidity data base system . SETTING All hospitals within Western Australia . PARTICIPANTS A total of 2566 women with PCOS hospitalized from 1997 - 2011 and 25 660 r and omly selected age-matched women without a PCOS diagnosis derived from the electoral roll . MAIN OUTCOME MEASURES Hospitalizations by ICD-10-M diagnoses from 15 years were compared . RESULTS Hospitalizations were followed until a median age of 35.8 years ( interquartile range , 31.0 - 39.9 ) . PCOS was associated with more nonobstetric and non-injury-related hospital admissions ( median , 5 vs 2 ; P < .001 ) , a diagnosis of adult-onset diabetes ( 12.5 vs 3.8 % ) , obesity ( 16.0 vs 3.7 % ) , hypertensive disorder ( 3.8 vs 0.7 % ) , ischemic heart disease ( 0.8 vs 0.2 % ) , cerebrovascular disease ( 0.6 vs 0.2 % ) , arterial and venous disease ( 0.5 vs 0.2 % and 10.4 vs 5.6 % , respectively ) , asthma ( 10.6 vs 4.5 % ) , stress/anxiety ( 14.0 vs 5.9 % ) , depression ( 9.8 vs 4.3 % ) , licit/illicit drug-related admissions ( 8.8 vs 4.5 % ) , self-harm ( 7.2 vs 2.9 % ) , l and transport accidents ( 5.2 vs 3.8 % ) , and mortality ( 0.7 vs 0.4 % ) ( all P < .001 ) . Women with PCOS had a higher rate of admissions for menorrhagia ( 14.1 vs 3.6 % ) , treatment of infertility ( 40.9 vs 4.6 % ) , and miscarriage ( 11.1 vs 6.1 % ) and were more likely to require in vitro fertilization ( 17.2 vs 2.0 % ) . CONCLUSION PCOS has profound medical implication s for the health of women , and health care re sources should be directed accordingly CONTEXT Polycystic ovary syndrome ( PCOS ) affects 6%-21 % of women . PCOS has been associated with an increased risk of dysglycemia including gestational diabetes mellitus ( GDM ) and type 2 diabetes mellitus ( T2DM ) . OBJECTIVE The objective of the study was to assess the prevalence of dysglycemia and the impact of obesity in young reproductive-aged women with and without PCOS in a community-based cohort . DESIGN This was a cross-sectional analysis of data from a large longitudinal study ( the Australian Longitudinal Study on Women 's Health ) . SETTING The setting for the study was the general community . PARTICIPANTS Women were r and omly selected from the national health insurance data base . St and ardized data collection occurred at five survey time points ( years 1996 , 2000 , 2003 , 2006 , and 2009 ) . Data from survey 4 ( 2006 , n = 9145 , 62 % of original cohort aged 18 - 23 y ) were examined for this study . MAIN OUTCOME MEASURES Self-reported PCOS , GDM , and T2DM were measured . RESULTS In women aged 28 - 33 years , PCOS preval 
    Output:
    
Clear contributors to heterogeneity did not emerge in meta-regression .
WIDER IMPLICATION S Our findings underscore the importance of PCOS as a cause of dysglycemia with a higher prevalence of IGT and T2DM .