hyperuricemia , defined as high levels of blood uric acid , is the major etiological factor of gout ( 1 ) , recently , increasing serum levels of uric acid ( sua ) has been found to be linked to the prevalence of the metabolic syndrome , cardiovascular diseases , cerebrovascular disease and it was found as a predictor of micro albuminuria and renal dysfunction ( 27 ) . in recent years , the prevalence of hyperuricemia in china is dramatically increasing , about 18.66% ( 8) . hyperuricemia induces vascular diseases , possibly through the generation of reactive oxygen species and subsequent endothelia dysfunction , which exerts the pro - inflammatory effects ( 9 ) . kenneth rock noted that uric acid might be an activator of the immune system by stimulating dendritic cell maturation and t lymphocytes ( 10 ) . the il-1/il-1r pathway maybe explained the inflammatory link between sua and endothelial dysfunction ( 11 ) . uric acid can also inhibit endothelial generation of nitric oxide that induces lipid oxidization and impairs endothelium - dependent vasodilation ( 12 ) . sua was increasing in postmenopausal women ( 13 ) , which may increase the risk of cardiovascular diseases , metabolic syndrome , diabetes and other chronic metabolic diseases ( 1417 ) . one possible explanation of physical mechanisms was estrogenic signaling might decrease sua through affecting the activity of renal ( 18 ) . it is well known that stronger estrogenic effect is a major etiology of uterine fibroids and fibrocystic breast disease ( 20 , 21 ) . factors increase overall lifetime exposure to estrogen , such as obesity and early menarche , are positively associated with the incidence of uterine fibroids ( 22 ) . in patients suffering from uterine fibroids and fibrocystic breast disease , whether sua are lower than the general due to stronger estrogenic effect ? if so , it may offer evidence to support the role of estrogenic effect on sua metabolism in females . this study selected participants with uterine fibroids , fibrocystic breast disease or uterine fibroids combining with fibrocystic breast disease as cases , and participants without these diseases as controls . thereby , we can explore whether estrogenic effect can regulate sua and open a new view to prevent and treat hyperuricemia in females . all participants were regular and registered staffs or retirees of enterprises and institutions in dongying city with the benefit of free health check - up once a year . participants were selected from health check - up records of a general hospital in shandong province from jan 2011 to jan 2012 . we included 5728 female participants with an age range of 1972 yr who had intact health check - up records . exclusion criteria for participants : fasting blood glucose ( fbg)>8.00 mmol / l ( osmotic diuresis critical point is 8.96mmol / l ) ; ast100u / l or alt100u / l ; creatinine clearance ( ccr)<50ml-/min or blood uric nitrogen ( bun)>9mmol / l ( 23 ) ; currently using diuretics , allopurinol or uricosuric agents ; gout patients ; surgery history of hysterectomy , mastectomy or ovarian cystectomy ; current or former hormone replace therapy ( hrt ) users ; present or past histories of endometriosis , ovarian tumors and polycystic ovarian syndrome ; current in the stage of pregnancy or breastfeeding . finally , a total of 5555 female participants were recruited . the study set up three cases : case i 568 uterine fibroids patients aged 1972 yr ; case ii 608 fibrocystic breast disease patients aged 19 - 54 yr ; case iii 173 patients diagnosed with both uterine fibroids and fibrocystic breast disease aged 1954 yr . the study set up two controls : control i 4206 people without uterine fibroids and fibrocystic breast disease aged 1972 yr ( vesus case i ) ; control ii 3762 people from control i excluding age above 54 yr ( vesus case ii and case iii ) . the oldest uterine fibroids patients were 72 yr old and no fibrocystic breast disease patients were older than 54 yr old . since sua differs in women s lifespan due to menopause , for each condition , participants were further divided into different age groups : 1944 ( reproductive period ) , 4554 ( menopause ) , 5559 ( early post - menopause ) and 60 ( post - menopause ) for case i and control i ; 1944 ( reproductive period ) and 4554 ( menopause ) for case ii , case iii and control ii . standardized interviews and self - reported questionnaires were used to obtain the following information : age ( in years ) ; medical history including cardiovasculuar diseases , metabolic diseases , uterine fibroids , endometriosis , fibrocystic breast disease , ovarian tumors , polycystic ovarian syndrome and so on ; operation history including hysterectomy , mastectomy , ovarian cystectomy and so on ; use of prescription medication including anti - hypertensives , allopurinol , uricosuric agents , hormone use and so on ; histories of pregnancy , delivery and breast feeding . body mass index ( bmi ) was calculated by dividing the weight in kilograms by the square of the height in metres . blood pressure ( bp ) was obtained from the right arm of the subject in a relaxed , sitting position after 5 min rest . systolic blood pressure ( sbp ) and diastolic blood pressure ( dbp ) were recorded for twice by mercury sphygmomanometers . blood samples were obtained by venipuncture in the morning after fasting overnight ( at least 12 h ) . laboratory test included : fasting blood glucose ( fbg ) , total cholesterol level ( t - ch ) , triglyceride ( tg ) , glutamic - pyruvic transaminase ( alt ) , glutamic - oxalacetic transaminase ( ast ) , blood uric nitrogen ( bun ) , blood creatinine ( cr ) and sua . glomerular filtration rate ( gfr ) , estimated by creatinine clearance ( ccr ) using the cockcroft - gault ( cg ) formula : ( 140 age )  weight/(serum creatinine85 ) . uterine fibroids and fibrocystic breast disease were confirmed by professional gynecologistis according to the standard protocol of the health check - up institute ( 24 , 25 ) . if variances were homogenious , the mean differences between groups were compared by student s t test . a p - value of less than 0.10 was considered to be statistically significant when comparing differences between cases and control by student s t test . after adjustment for covariant variables , the associations between the two kinds of diseases and sua were evaluated using the generalized linear regression mode . the study set sua as the dependent variable ; the presence of diseases from cases as the independent variable ; risk factors selected based on results of independent - sample t test ( p<0.10 ) as covariant variables . compared with controls , partial regression coefficient  of cases represented differences of sua ( ug / l ) between the case and control . a p - value of less than 0.05 was considered to be statistically significant by generalized linear regression mode . all participants were regular and registered staffs or retirees of enterprises and institutions in dongying city with the benefit of free health check - up once a year . participants were selected from health check - up records of a general hospital in shandong province from jan 2011 to jan 2012 . we included 5728 female participants with an age range of 1972 yr who had intact health check - up records . exclusion criteria for participants : fasting blood glucose ( fbg)>8.00 mmol / l ( osmotic diuresis critical point is 8.96mmol / l ) ; ast100u / l or alt100u / l ; creatinine clearance ( ccr)<50ml-/min or blood uric nitrogen ( bun)>9mmol / l ( 23 ) ; currently using diuretics , allopurinol or uricosuric agents ; gout patients ; surgery history of hysterectomy , mastectomy or ovarian cystectomy ; current or former hormone replace therapy ( hrt ) users ; present or past histories of endometriosis , ovarian tumors and polycystic ovarian syndrome ; current in the stage of pregnancy or breastfeeding . finally , a total of 5555 female participants were recruited . the study set up three cases : case i 568 uterine fibroids patients aged 1972 yr ; case ii 608 fibrocystic breast disease patients aged 19 - 54 yr ; case iii 173 patients diagnosed with both uterine fibroids and fibrocystic breast disease aged 1954 yr . the study set up two controls : control i 4206 people without uterine fibroids and fibrocystic breast disease aged 1972 yr ( vesus case i ) ; control ii 3762 people from control i excluding age above 54 yr ( vesus case ii and case iii ) . the oldest uterine fibroids patients were 72 yr old and no fibrocystic breast disease patients were older than 54 yr old . since sua differs in women s lifespan due to menopause , for each condition , participants were further divided into different age groups : 1944 ( reproductive period ) , 4554 ( menopause ) , 5559 ( early post - menopause ) and 60 ( post - menopause ) for case i and control i ; 1944 ( reproductive period ) and 4554 ( menopause ) for case ii , case iii and control ii . standardized interviews and self - reported questionnaires were used to obtain the following information : age ( in years ) ; medical history including cardiovasculuar diseases , metabolic diseases , uterine fibroids , endometriosis , fibrocystic breast disease , ovarian tumors , polycystic ovarian syndrome and so on ; operation history including hysterectomy , mastectomy , ovarian cystectomy and so on ; use of prescription medication including anti - hypertensives , allopurinol , uricosuric agents , hormone use and so on ; histories of pregnancy , delivery and breast feeding . body mass index ( bmi ) was calculated by dividing the weight in kilograms by the square of the height in metres . blood pressure ( bp ) was obtained from the right arm of the subject in a relaxed , sitting position after 5 min rest . systolic blood pressure ( sbp ) and diastolic blood pressure ( dbp ) were recorded for twice by mercury sphygmomanometers . blood samples were obtained by venipuncture in the morning after fasting overnight ( at least 12 h ) . laboratory test included : fasting blood glucose ( fbg ) , total cholesterol level ( t - ch ) , triglyceride ( tg ) , glutamic - pyruvic transaminase ( alt ) , glutamic - oxalacetic transaminase ( ast ) , blood uric nitrogen ( bun ) , blood creatinine ( cr ) and sua . glomerular filtration rate ( gfr ) , estimated by creatinine clearance ( ccr ) using the cockcroft - gault ( cg ) formula : ( 140 age )  weight/(serum creatinine85 ) . uterine fibroids and fibrocystic breast disease were confirmed by professional gynecologistis according to the standard protocol of the health check - up institute ( 24 , 25 ) . if variances were homogenious , the mean differences between groups were compared by student s t test . a p - value of less than 0.10 was considered to be statistically significant when comparing differences between cases and control by student s t test . after adjustment for covariant variables , the associations between the two kinds of diseases and sua were evaluated using the generalized linear regression mode . the study set sua as the dependent variable ; the presence of diseases from cases as the independent variable ; risk factors selected based on results of independent - sample t test ( p<0.10 ) as covariant variables . compared with controls , partial regression coefficient  of cases represented differences of sua ( ug / l ) between the case and control . a p - value of less than 0.05 was considered to be statistically significant by generalized linear regression mode . demographic and biochemical parameters of participants according to cases and age categories were listed in table 1 ( for uterine fibroids and control ) , table 2 ( for fibrocystic breast disease and control ) and table 3 ( for uterine fibroids combining with fibrocystic breast disease and control ) . demographic data and laboratory parameters in the case of uterine fibroids and control note : values expressed as mean ( sd ) ; abbreviations : bmi , body mass index ; sbp , systolic blood pressure ; dbp , diastolic blood pressure ; t - ch , total cholesterol level ; tg , triglyceride ; fbg , fasting blood glucose ; sua , serum levels of uric acid . demographic data and laboratory parameters in the case of fibrocystic breast disease and control note : values expressed as mean ( sd ) demographic data and laboratory parameters in the case of uterine fibroids combining with fibrocystic breast disease and control note : values expressed as mean ( sd ) from table 1 ( for uterine fibroids and control ) , totally for all ages , bmi , t - ch , tg and fbg of the case were higher compared with the control but sua were lower . when considering age categories , from 1944 yr , bmi , sbp , dbp , t - ch , tg and fbg of the case were higher than the control ; from 4554 yr , it was found only t - ch in the case were lower than that in the control ; from 5559 yr , bmi , sbp , dbp , t - ch , fbg and sua of the case were lower than the control ; from 6072 yr , bmi , sbp , dbp and sua of the case were lower than the control . from table 2 ( for fibrocystic breast disease and control ) , totally for all ages , bmi , sbp , dbp , tg and sua in the case were lower than the control . when considering age categories , from 1944 yr , bmi , sbp , tg and sua of the case were lower than the control ; from 4554 yr , dbp and tg of the case were lower than the control . from table 3 ( for uterine fibroids combining with fibrocystic breast disease and control ) , totally for all ages , only sua of the case were lower than the control . when considering age categories , from 1944 yr , bmi and t - ch of the case were higher than the control ; from 4554 yr , bmi , sbp , dbp and sua of the case were lower than the control . to compare differences of sua between cases and controls , the study built 11 generalized linear regression models according to age categories among three cases ( the note of table 4 showed adjusted variables in different models respectively ) covariant variables entered generalized linear regression models were selected by t test at the standard of p<0.10 , as follows from table 13 . in comparison with controls , sua of three cases decreased by 9.62 umol / l , 4.69 umol / l and 10.91 umol / l respectively . when taking age into consideration , the decreasing sua differed from each other . from 19 to 44 yr , sua of case i to case iii were lower than controls by 8.46 umol / l ( p=0.011 ) , 5.88 umol / l ( p=0.014 ) and 9.39 umol / l ( p=0.059 ) , respectively . from 4554 yr , no significant differences were between three cases and controls . in case i and its control : from 5459 yr , differences were not significant ; from 60 to 72 yr , sua in case i was lower than the control by 32.02 umol / l ( p=0.003 ) . differences in sua ( umol / l ) among cases and controls of different age groups by generalized linear regression adjusted for bmi , t - ch , tg , fbg and age ; adjusted for bmi , sbp , dbp , tg , t - ch and fbg ; adjusted for bmi , sbp , dbp , t - ch and fbg ; adjusted for bmi , sbp and dbp ; adjusted for bmi , sbp , dbp , tg and year ; adjusted for bmi , sbp and tg ; adjusted for dbp and tg ; adjusted for bmi and t - ch ; adjusted for bmi , sbp and dbp . demographic and biochemical parameters of participants according to cases and age categories were listed in table 1 ( for uterine fibroids and control ) , table 2 ( for fibrocystic breast disease and control ) and table 3 ( for uterine fibroids combining with fibrocystic breast disease and control ) . demographic data and laboratory parameters in the case of uterine fibroids and control note : values expressed as mean ( sd ) ; abbreviations : bmi , body mass index ; sbp , systolic blood pressure ; dbp , diastolic blood pressure ; t - ch , total cholesterol level ; tg , triglyceride ; fbg , fasting blood glucose ; sua , serum levels of uric acid . demographic data and laboratory parameters in the case of fibrocystic breast disease and control note : values expressed as mean ( sd ) demographic data and laboratory parameters in the case of uterine fibroids combining with fibrocystic breast disease and control note : values expressed as mean ( sd ) from table 1 ( for uterine fibroids and control ) , totally for all ages , bmi , t - ch , tg and fbg of the case were higher compared with the control but sua were lower . when considering age categories , from 1944 yr , bmi , sbp , dbp , t - ch , tg and fbg of the case were higher than the control ; from 4554 yr , it was found only t - ch in the case were lower than that in the control ; from 5559 yr , bmi , sbp , dbp , t - ch , fbg and sua of the case were lower than the control ; from 6072 yr , bmi , sbp , dbp and sua of the case were lower than the control . from table 2 ( for fibrocystic breast disease and control ) , totally for all ages , bmi , sbp , dbp , tg and sua in the case were lower than the control . when considering age categories , from 1944 yr , bmi , sbp , tg and sua of the case were lower than the control ; from 4554 yr , dbp and tg of the case were lower than the control . from table 3 ( for uterine fibroids combining with fibrocystic breast disease and control ) , totally for all ages , only sua of the case were lower than the control . when considering age categories , from 1944 yr , bmi and t - ch of the case were higher than the control ; from 4554 yr , bmi , sbp , dbp and sua of the case were lower than the control . to compare differences of sua between cases and controls , the study built 11 generalized linear regression models according to age categories among three cases ( the note of table 4 showed adjusted variables in different models respectively ) . covariant variables entered generalized linear regression models were selected by t test at the standard of p<0.10 , as follows from table 13 . in comparison with controls , sua of three cases decreased by 9.62 umol / l , 4.69 umol / l and 10.91 umol / l respectively . when taking age into consideration , the decreasing sua differed from each other . from 19 to 44 yr , sua of case i to case iii were lower than controls by 8.46 umol / l ( p=0.011 ) , 5.88 umol / l ( p=0.014 ) and 9.39 umol / l ( p=0.059 ) , respectively . from 4554 yr , no significant differences were between three cases and controls . in case i and its control : from 5459 yr , differences were not significant ; from 60 to 72 yr , sua in case i was lower than the control by 32.02 umol / l ( p=0.003 ) . differences in sua ( umol / l ) among cases and controls of different age groups by generalized linear regression adjusted for bmi , t - ch , tg , fbg and age ; adjusted for bmi , sbp , dbp , tg , t - ch and fbg ; adjusted for bmi , sbp , dbp , t - ch and fbg ; adjusted for bmi , sbp and dbp ; adjusted for bmi , sbp , dbp , tg and year ; adjusted for bmi , sbp and tg ; adjusted for dbp and tg ; adjusted for bmi and t - ch ; adjusted for bmi , sbp and dbp . based on a large sample of health check - up records , the study showed that people suffering from uterine fibroids , fibrocystic breast disease or uterine fibroids combined with fibrocystic breast disease had a significantly lower sua than controls except periods of menopause and early post - menopause , which indirectly supported our primary hypothesis that estrogenic effect may positively adjust sua metabolism in females . in the health check - up survey , it was unrealistic to determine menopausal period through testing serum estradiol levels in a large sample . so we divided age groups based on former chinese epidemiological data . according to lin li s study of 21,113 women aged 4065 yr in 13 cities , china , age at natural menopause was most between 45 to 55 yr and only no more than 3% of women were still at menopause between 55 to 60 yr ( 26 ) . so we set age groups as 1944 ( reproductive period ) , 4554 ( menopause ) , 5559 ( early post - menopause ) and 60 ( post - menopause ) . in our study , the oldest uterine fibroids patients were 72 yr old , so we set the highest age category as 6072 yr in the case of uterine fibroids . some scholars may doubt that after menopause , as the ovaries s function declines , some uterine fibroids tend to atrophy without estrogenic effect . however , uterine fibroids are still the most common benign tumors in postmenopausal women ( 27 ) . bachmann suggested that after menopause , ovaries still continue to produce testosterone , and peripheral tissues metabolize testosterone to active estrogen ( 28 ) . additionally , adipose tissue is able to produce increasing levels of estrogen with age at the time of menopause ( 29 ) . on the other hand , the estrogen receptor - alpha ( er- , a kind of estrogen receptors ( ers ) , estrogen becomes functional mainly in the presence of er- ( 30))gene polymorphisms have been reported to be associated with uterine leiomyoma risk ( 31 ) , which have no relationships with aging . so , it is reasonable to include participants among the age category of 6072 yr . fibrocystic breast disease become most evident in women between 35 and 55 yr of age ( 32 ) . it is caused by a proliferation of epithelial cells in the lobulo - alveolar region . after menopause , women s breast epithelial tissue has become atrophic with changed respond to hormonal messengers ( 32 ) . generally , in post - menopausal women , few of them suffer from this kind of disease . so in this study , no patients of fibrocystic breast disease were older than 54 yr old . the two key steps in keeping normal sua are synthesis in liver and excretion in kidney . we excluded participants whose liver and kidney function were damaged judged by laboratory indexs : transaminases that reflect liver function ; ccr and bun that reflect glomerular filtration function . moreover , osmotic diuresis due to hyperglycaemia can decrease sua pathologically , so we excluded people whose fbg>8.00 mmol / l . uterine fibroids and fibrocystic breast disease were related to body size , diabetes and atherosclerosis ( 3335 ) and these factors also influence uric acid metabolism ( 2 ) . to keep comparative groups matched , we adjusted bmi , sbp , dbp , t - ch , tg and fbg by generalized regression model . however , we did not include ccr as an adjusted variable like former studies did , because maybe ccr is an intermediary variable in the analysis between estrogenic effect and sua ( 36 ) . moreover , from table 13 , it was found that differences of these parameters between 3 pairs of cases and controls were variated according to age categories , so the study built 11 individual generalized linear regression models to fit for different conditions referred to diseases and age . stronger estrogenic effect ( higher level of estrogen binding higher express of ers ) than normal plays an important part in the etiology of uterine fibroids and cyclomastopathy ( 30 , 37 ) . it has been reported that estrogenic effect can regulate the metabolism of sua ( 18 ) . in renal , estrogen induces fractional excretion of uric acid and higher levels of estradiol leads a lower postsecretory tubular reabsorption of urate ( 18 ) . wang w indicated that gene polymorphism of er- affects sua reduction after bariatric surgery ( 39 ) . therefore , due to higher estrogenic effect on regulation of sua , participants with uterine fibroids and fibrocystic breast disease in our study had lower sua than controls . when exploring sua in uterine fibroids patients according to age categories , although in groups of reproductive period and post - menopause period , sua in cases were all lower than controls , but differed in ranges . in the age category of 1944 yr ( reproductive period ) , the case was 9.62umol / l lower than control , which is not as great as that in the age category of 6072 yr ( the case was 32.02 . the possible reason may be : the physiological effect of estrogen are realized by enough levels of estrogen binding active ers . in the reproductive period , no matter in the case or the control , generally , endogenous estrogen level is relatively higher overall , which can ensure the normal regulation on metabolism . thus , sua of the control was relatively lower ( 237.05 umol / l ) compared with participants after menopause ( 271.22 umol / l ) . and however , among people of 6072 yr ( post - menopause period ) , in general , endogenous estrogen level is lower than premenopause because of weakened ovarian function . therefore it is reasonable that after menopause , losing protection of estrogenic effect , females are likely to suffering from hyperuricemia ( 13 ) . however , in people with uterine fibroids , a stronger er- immunoreactivity was observed in the post - menopausal group compared with the premenopausal group ( 40 ) . high activity of ers keep people with uterine fibroids after menopause can still have strong estrogenic effect , which can protectively decrease sua in a certain degree . in the group of post - menopause period , moreover , if estrogenic effect can decrease sua , in menopause ( 4554 yr old ) group and early post - menopause ( 5559 yr old ) group , why we found that the difference of sua was not obvious between the case and control ( p - values are 0.725 and 0.21 separately ) ? possible explanation of the result is that throughout menopause , levels of different hormones rise and fall : 1- the abnormal metabolism of female is due to raised level of androgens ( 41 , 42 ) . 2-the eccentric raised level of glucocorticoid may hamper the activity of estrogen ( 43 , 44 ) . how estrogeic effect realizes its function on sua ? whether it is relied on higher level of estrogen or stronger effect of ers ? many studies have explored the role of estrogen ( especially exogenous estrogen ) for adjusting sua . . showed that hormone replacement therapy ( hrt ) reduced sua in certain group of postmenopausal women with hyperuricaemia ( 45 ) . based on the third national health and nutrition examination survey , hak et al . got similar results ( 13 ) however , after using hrt , sua did not change significantly in post - menopausal women ( 36 ) . maybe , the controversial outcomes from hrt were due to different effects of ers among individuals . recently , it is found that ers , especially er- play an essential role in the realization of estrogenic effect , which differs according to their genotypes ( 39 , 46 ) . moreover , stronger effect of er- plays an important part in the etiology of uterine fibroids and fibrocystic breast disease ( 37 , 47 ) . brandon discoverd that ers gene expression increased in leiomyoma compared with normal myometrium ( 48 ) . so maybe , stronger effect of ers may be another mechanism for lower sua in uterine fibroids and fibrocystic breast disease patients compared with controls in our study . only with health check - up data , we can not be sure which one , higher level of estrogen or stronger effect of ers , is more important for estrogenic effect on sua . further studies can focus on : 1 ) explore ers functions for regulating sua through immunohistochemistry from related biopsy samples or ex - vivo experiments ; 2 ) compare serum active estrogen s levels ( like estradiol ) from patients of uterine fibroids and fibrocystic breast disease with the general . since this is a cross  sectional study , we could nt determine a casual relationship . in addition we did not partition disease grades according to the severity of uterine fibroids and fibrocystic breast disease , so we could not analyze dose - response of exposure and outcome . participants of uterine fibroids and fibrocystic breast disease had a lower sua except the stage of menopause . that may indirectly support that estrogenic effect can protectively keep sua at a relatively lower level in females . this study was approved by the ethics committee of school of public health , shandong university and informed oral consent was obtained from each participant . since many individuals invovled in this study were workers from rural areas , some of whom were illiterate , the informed consent was read and explained by investigators , and participants were told that their health examination data might be applied for reaserch without private information leakage ( including name , contact information and so on ) . the whole process was recorded by voice recorders ( recorder pens ) , which can supervise behaviors of investigators and keep qualities of the survey .
background : increasing serum levels of uric acid ( sua ) after menopause in women brought up a hypothesis that estrogenic effect may protectively regulate sua . 
 estrogenic effect is a major etiology of uterine fibroids and fibrocystic breast disease . 
 the study aimed to explore sua among patients suffering from these diseases to enhance the hypothesis.methods:overall , 1349 female participants were selected into three cases : case i having uterine fibroids ( n=568 ) , case ii having fibrocycstic breast disease ( n=608 ) and case iii having uterine fibroids combining with fibrocycstic breast disease ( n=173 ) ; 4206 participants without these diseases were selected as controls . based on health check - up data from 2011 to 2012 , in dongying shengli oilfield central hospital , 
 a cross - sectional study was conducted to examine the difference in sua between the case and control . 
 we adjusted covariates by generalized linear regression mode.results:from 19 to 44 yr , sua of case i to case iii were lower than controls by 8.46 umol / l ( p=0.011 ) , 5.88umol / l ( p=0.014 ) and 9.39 umol / l ( p=0.059 ) , respectively . from 4554 yr , 
 no significant differences were between three cases and controls . in case i and its control : from 5459 yr , differences were not significant ; from 60 to 72 yr , sua in case i was lower than the control by 32.02umol / l ( p=0.003).conclusion : participants of uterine fibroids and fibrocystic breast disease had a lower sua except the stage of menopause , which indirectly supported that estrogenic effect , may protectively decrease sua .