polycystic ovary syndrome ( pcos ) is the most common endocrine disease and metabolic disorder in adolescence and reproductive women , which is the first reason for female infertility , with the incidence of 510% in reproductive women . it is characterized by chronic anovulation , hyperandrogenism , and ovarian polycystic changes under ultrasound in clinic . the etiology of pcos is still not very clear , but previous studies have shown that pcos is closely related to lipid metabolism disorder and insulin resistance [ 2 , 3 ] . pcos patients are often accompanied by obesity , insulin resistance , abnormal glucose metabolism , lipids disorder , hypertension , and other risk factors of cardiovascular disease ( cvd ) . lipids disorder is present when tg and ldl - c levels elevate with a lower hdl - c level , which is closely related to insulin resistance . there is insulin resistance in about 70% of pcos patients and 10% with diabetes mellitus [ 79 ] . insulin resistance is still closely related to crp , lipids disorder , and other risk factors of cad even if the glucose metabolism is normal . using biguanides or thiazolidinediones ( tzds ) to treat insulin resistance in pcos patients has achieved satisfactory clinical effects [ 11 , 12 ] . it is of great clinical importance to determine whether the pcos patients are combined with insulin resistance and to take treatments for insulin resistance for symptom improvement and long - term prognosis in pcos patients . the majority of those methods to evaluate insulin resistance are complicated to operate , expensive , and time - consuming . there is , therefore , an urgentneedto develop a simple , effective , and economic method to investigate insulin resistance in pcos . the aim of this research was to study the correlation between serum lipoprotein ratios ( tg / hdl - c , tc / hdl - c , and ldl - c / hdl - c ) and insulin resistance in pcos to provide new ideas for evaluation and treatment of pcos with insulin resistance . from february 2010 to october 2011 , 105 patients diagnosed with pcos in the endocrinology clinic in our hospital were enrolled in the pcos group ( according to pcos diagnostic criteria revised in the 2003 rotterdam meeting ) . this study was conducted with approval from the ethics committee ofthe third affiliated hospital of suzhou university . written informed consent was obtained from all participants . the age of patients ranged from 17 to 36 years ( average age : 24.8 years ) , who had no history of drugs affecting glucose and lipid metabolism . 109 healthy females ( with normal menstrual cycle and sex hormone level , no evidence of polycystic ovary on ultrasound examination ) were randomly selected as controls ( control group ) from the medical examination center of our hospital . the age of the controls ranged from 18 to 35 years ( an average age : 25.2 years ) . plasma samples were obtained in early follicular period from all participants after an overnight fasting to measure lh , fsh , e2 , t , fbg , fins , tg , tc , ldl - c , and hdl - c . then , the ratio of tg/ hdl - c , tc/ hdl - c , and ldl - c / hdl - c was calculated . their height , weight , waist circumference ( wc ) , and blood pressure were measured , and the body mass index ( bmi ) was calculated . insulin resistance index was calculated with homeostasis model assessment ( homa - ir ) , homa - ir  =  fbg ( mmol / l )    fins ( miu / l)/22.5 . the diagnostic criterion of pcos with insulin resistance ( ir ) was homa - ir  >  2.77 . evaluation of serum lipoprotein ratios with roc curve was used to diagnose the sensitivity and specificity of pcos with insulin resistance . bmi , wc , sbp , dbp , lh , t , fbg , fins , homa - ir , tg , tc , ldl - c , tg / hdl - c , tc / hdl - c , and ldl - c / hdl - c were significantly higher in pcos group than in control group . there was no significant difference between pcos and control groups in terms of fsh and e2 ( table 1 ) . there was a significant positive correlation between homa - ir and tg / hdl - c ( r = 0.552 , p < 0.001 ) , tc / hdl - c ( r = 0.561 , p < 0.001 ) and ldl - c / hdl - c ( r = 0.531 , p < 0.001 ) , respectively . it was shown that tg / hdl - c , tc / hdl - c , and ldl - c / hdl - c were effective diagnostic markers for pcos with insulin resistance , and the area under the roc curve of tc / hdl - c was the biggest ( table 2 , figure 1 ) with high sensitivity ( 93.2% ) and specificity ( 83.8% ) ( tc / hdl - c > 3.6 ) . recent studies have considered pcos as not only a reproductive endocrine disease but also metabolic disorder , which is related to hyperinsulinemia , hyperlipidemia , diabetes , and cardiovascular disease . insulin resistance and concurrent hyperinsulinemia were reported to play a key role in its occurrence and pathophysiology [ 14 , 15 ] . pcos symptoms can be improved if insulin resistance is controlled after lifestyle intervention and biguanides and tzds usage . thus , a simple , reliable , and economical method to evaluate insulin resistance will greatly contribute to diagnosis , treatment , and prognosis of pcos . insulin resistance is defined clinically as the inability of a known quantity of exogenous or endogenous insulin to increase glucose uptake and utilization in an individual as much as it does in a normal population . there are many methods of evaluation of insulin resistance , among which the hyperinsulinemic euglycemic clamp technique is considered as the  gold standard  to assess insulin sensitivity ; however , it was complicated to operate and time - consuming which , limited its use in clinical and epidemiological studies . other evaluation methods of insulin resistance , such as the homa - ir of minimal model and steady - state model , bennett index , li guangwei index , insulin sensitivity check index ( quicki ) , and fasting glucose and insulin ratio ( g / i ) , are more complex , time - consuming , and expensive . recent studies have shown that 2-hour blood glucose level after oral glucose tolerance test ( ogtt ) can be used as a reliable indicator for evaluation of insulin resistance in pcos patients , but it is also more complex and expensive . there is , therefore , an urgentneedto develop a simple , effective , and economic method to investigate insulin resistance in pcos . the result of this study showed that pcos patients had higher tc , ldl - c , and tg and lower hdl - c when compared with age - matched healthy females . previous studies have shown that serum lipoprotein ratios ( tg / hdl - c , tc / hdl - c , and ldl - c / hdl - c ) have significant positive correlation with insulin resistance in patients with type 2 diabetes and could be considered as a simple reliable indicator to determine insulin resistance . similarly , the tg / hdl - c ratio also had significant positive correlation with insulin resistance in nondiabetic obese individuals . in the present study , the homa - ir of the pcos patients was significantly higher than that of the age - matched healthy women , which suggested that insulin resistance had a crucial role in pathogenesis of pcos . meanwhile , it was also found that tg / hdl - c , tc / hdl - c , and ldl - c / hdl - c of pcos patients were significantly higher than those of the age - matched healthy women and had a significant positive correlation with homa - ir . roc curve analysis showed that tg / hdl - c , tc / hdl - c , and ldl - c / hdl - c were effective diagnostic markers of pcos with insulin resistance , and the area under the roc curve of tc / hdl - c was the biggest with the highest sensitivity and specificity ( tc / hdl - c  >  3.6 ) . the research showed that serum lipoprotein ratios had significant positive correlation with insulin resistance in pcos patients , which could be used as a simple , reliable , and economic indicator to evaluate insulin resistance .
objective . to investigate the association between serum lipoprotein ratios and insulin resistance in women with polycystic ovarian syndrome ( pcos ) 
 . methods . 105 pcos patients and 109 controls 
 were randomly enrolled in the study . 
 serum levels of luteinizing hormone ( lh ) , follicle - stimulating hormone ( fsh ) , estradiol ( e2 ) , total testosterone ( t ) , fasting glucose ( fbg ) , fasting insulin ( fins ) , serum triglycerides ( tg ) , total cholesterol ( tc ) , high - density lipoprotein ( hdl - c ) , and low - density lipoprotein ( ldl - c ) levels were checked , and then tg / hdl - c ratio , tc / hdl - c , ratio and ldl - c / hdl - c ratio were calculated . 
 the homeostasis model assessment of insulin resistance ( homa - ir ) was used to calculate the insulin resistance . 
 results . 
 all lipoprotein ratios were significantly higher in pcos patients as compared to healthy controls ( p < 0.05 ) . 
 tg / hdl - c ratio , tc / hdl - c ratio , and ldl - c / hdl - c ratio were significantly correlated with homa - ir ( p < 0.05 ) . 
 the roc curve demonstrated that tc / hdl - c ratio had higher sensitivity and specificity in diagnosing pcos with insulin resistance . conclusion . 
 this study demonstrates that serum lipoprotein ratio significantly correlates with insulin resistance and can be used as the marker of insulin resistance in pcos patients .