human
***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: Insulin resistance is one of the most common features of polycystic ovary syndrome ( PCOS ) . Some studies suggest that vitamin D deficiency may have a role in insulin resistance ; thus , the aim of the current study was to determine the effect of vitamin D supplementation on insulin resistance in women with PCOS and a vitamin D deficiency . We hypothesized that vitamin D supplementation would lower the glucose level and insulin resistance in women with PCOS and a vitamin D deficiency . The current study was a r and omized , placebo-controlled , double-blinded trial with 50 women with PCOS and a vitamin D deficiency , 20 to 40 years old , assigned to receive 3 oral treatments consisting of 50,000 IU of vitamin D₃ or a placebo ( 1 every 20 days ) for 2 months ( vitamin D , n = 24 ; placebo , n = 26 ) . The fasting blood glucose , insulin , 25-hydroxyvitamin D , and parathyroid hormone levels , as well as the homeostasis model assessment of insulin resistance and quantitative insulin sensitivity check index were measured at baseline and after treatment . In the vitamin D group , the serum level of 25-hydroxyvitamin D increased ( 6.9 ± 2.8 to 23.4 ± 6.1 ng/mL , P < .0001 ) , and the parathyroid hormone level decreased ( 70.02 ± 43.04 to 50.33 ± 21.99 μ IU/mL , P = .02 ) . There were no significant changes in the placebo group . There was a significant increase in insulin secretion in the vitamin D group ( P = .01 ) , but this was not significant compared with the placebo group . The fasting serum insulin and glucose levels and the insulin sensitivity and homeostasis model assessment of insulin resistance did not change significantly by the end of the study . We were not able to demonstrate the effect of vitamin D supplementation on insulin sensitivity and insulin resistance in women with PCOS and vitamin D deficiency OBJECTIVE The objective of the study was to examine changes of 25-hydroxy-vitamin D ( 25OHD ) and PTH blood levels 4 and 20 wk after low-calorie diet-induced weight loss . METHODS Forty-four obese women [ aged 40.6 + /- 11.4 yr , body mass index ( BMI ) 36.7 + /- 4.9 kg/m(2 ) ] and 25 controls ( BMI 22.9 + /- 1.5 kg/m(2 ) ) were examined .  Anthropometric and cardiometabolic parameters and 25OHD and PTH levels  were determined at baseline and 4 and 20 wk after a low-calorie diet . RESULTS At baseline , 25OHD levels were lower in obese compared with control subjects ( 17 + /- 6.0 vs. 23.8 + /- 8.7 ng/ml , P < 0.001 ) , whereas no differences were found in PTH levels . In all women , a negative correlation was found between 25OHD levels and body weight ( BW ) ( r -0.32 , P < 0.001 ) , BMI ( r -0.37 , P < 0.001 ) , waist circumference ( r -0.26 , P < 0.05 ) , and percent fat mass ( r -0.38 , P = 0.001 ) as determined by bioelectrical impedance analysis . The 4-wk low-calorie diet ( n = 37 ) reduced BW and led to significant improvements in the homeostasis model assessment ( HOMA ) index and lipid levels . The 20-wk low-calorie diet ( n = 26 ) result ed in reduction of BW and BMI by 10 % , HOMA index ( 4.7 + /- 3.8 vs. 3.10 + /- 1.7 , P < 0.01 ) , and lipids levels ( except high density lipoprotein cholesterol ) and increase in 25OHD ( 15.4 + /- 6.0 vs. 18.3 + /- 5.1 ng/ml , P < 0.05 ) , compared with baseline . PTH levels were unchanged . The increase of 25OHD levels was associated with the reduction of insulin levels and HOMA index ( r -0.43 , P < 0.05 ) . CONCLUSIONS Blood 25OHD levels were low in obese women and correlated inversely with severity measures of obesity . Weight loss of 10 % after low-calorie diet increased 25OHD levels , and this increase was mainly associated with improvement of insulin resistance BACKGROUND It has been shown that many women with polycystic ovary syndrome ( PCOS ) are 25-hydroxyvitamin D ( 25OHD ) insufficient . Both statin treatment and vitamin D supplementation have been shown to improve biochemical hyper and rogenemia , insulin resistance , and markers of inflammation in patients with PCOS , raising the possibility that some of the statin effects are mediated through vitamin D. METHODS We conducted this r and omized , double-blind placebo controlled study to assess the effect of atorvastatin on serum 25OHD concentrations in patients with PCOS . Forty medication-naive patients with PCOS were r and omized to either atorvastatin 20 mg daily or placebo for 3 months . After completing the initial 3 months of atorvastatin or placebo , both groups of patients participated in a 3-month extension study with metformin 1500 mg daily . We measured changes in 25OHD concentrations by use of t and em mass spectrometry . RESULTS Mean ( SD ) baseline 25OHD concentrations were comparable between the 2 groups [ 45.9 ( 2.4 ) vs 44.8 ( 1.8 ) nmol/L ; P = 0.7 ] . There was a significant increase in 25OHD concentrations with atorvastatin [ 45.9 ( 2.4 ) vs 60.8 ( 3.5 ) nmol/L ] compared with placebo [ 44.8 ( 1.8 ) vs 41.8 ( 3.2 ) nmol/L ; P = 0.02 ] . Three-month treatment with metformin maintained the improvement of 25OHD  with atorvastatin compared to baseline [ 45.9 ( 2.4 ) vs 61.8 ( 3.5 ) , P ≤ 0.01 ) . There were no significant changes in 25OHD concentrations in the placebo group after 12 weeks of metformin . CONCLUSIONS Among patients with polycystic ovary syndrome , 12 weeks of atorvastatin led to a clinical ly significant rise in 25OHD concentrations . This may represent a beneficial pleiotropic effect of statins on 25OHD concentrations Vitamin D functions are not limited to skeletal health benefits and may extend to preservation of insulin secretion and insulin sensitivity . This review summarizes the literature related to potential vitamin D influences on glucose homeostasis and insulin sensitivity . Cross-sectional data provide some evidence that circulating 25-hydroxyvitamin D ( 25(OH)D ) is inversely associated with insulin resistance , although direct measurements of insulin sensitivity are required for confirmation . Reported associations with insulin secretion , however , are contradictory . Available prospect i ve studies support a protective influence of high 25(OH)D concentrations on type 2 diabetes mellitus risk . There is a general lack of consistency in vitamin D intervention outcomes on insulin secretion and sensitivity , likely due to differences in subject population s , length of interventions , and forms of vitamin D supplementation . Vitamin D receptor gene polymorphisms and vitamin D interactions with the insulin like growth factor system may further influence glucose homeostasis . The ambiguity of optimal vitamin D dosing regimens and optimal therapeutic concentrations of serum 25(OH)D limit available intervention studies . Future studies , including cross-sectional and prospect i ve , should be performed in population s at high risk for both vitamin D deficiency and type 2 diabetes mellitus . Well- design ed , placebo-controlled , r and omized intervention studies are required to establish a true protective influence of  vitamin D on glucose homeostasis Background : Polycystic ovary syndrome ( PCOS ) is the most common endocrine disorder in females of reproductive age . Insulin resistance is a frequent metabolic disturbance in PCOS . Vitamin D deficiency is a common problem . Accumulating evidence suggests that vitamin D has a role on insulin sensitivity so may contribute to reduction of hyper and rogenemia . Objective : The aim was to determine the effects of vitamin D treatment in metabolic components and ovulation evidence in PCOS . Material s and Methods : Fifty one untreated PCOS patients were r and omly divided into three groups and treated with calcitriol , metformin , or placebo . Before and 3 months after treatment , ovulation evidence was assessed by ovarian trans abdominal sonography . Plasma fasting glucose , insulin , homeostasis model assessment insulin resistance ( HOMA-IR ) , 25-hydroxyvitamin D , parathyroid hormone and and rogen levels were measured before and after treatment . A 75gr glucose test was performed before and after treatment and two set of results was compared . Results : Three patients did not continue this study . Only 11 patient ( 22.9 % ) had sufficient vitamin D levels ( > 30 ng/ml ) . Metformin caused a significant decrease in weight ( p=0.027 ) , insulin level ( p=0.043 ) , and insulin resistance ( p=0.048 ) . Systolic blood pressure and PTH significantly improved after calcitriol ( p=0.029 , p=0.009 respectively ) . An improvement in ovulation was detected after calcitriol and seven patients , without evidence of ovulation before treatment , illustrated ovulation after 3 months . Difference with calcitriol in ovulation was significant versus other two methods ( p=0.02 ) . Conclusion : Calcitriol treatment in PCOS may be prior to metformin in ovulation induction Background : Vitamin D deficiency is prevalent among women , including patients with polycystic ovary syndrome ( PCOS ) . Some studies have suggested that vitamin D may have a role in cardiovascular disease ( CVD ) . There is very limited data on the vitamin D effect on CVD risk factors in women with PCOS and vitamin D deficiency . Aim : To investigate the effect of cholecalciferol on CVD risk factors in PCOS women with vitamin D deficiency . Methods : The study was a r and omized , placebo-controlled , double blinded trial . Fifty PCOS women with vitamin D deficiency ( vitamin D , no.=24 ; placebo , no.=26 ) aged 20–40 yr , were r and omly assigned to receive 3 oral capsules of 50 , 000 IU vitamin D3 or a placebo ( one capsule every 20 days ) for two months . Serum vitamin D , PTH , lipid profile , apolipoprotein AI ( APO-AI ) , and high sensitive C- reactive protein ( hs-CRP ) were measured at baseline and after treatment . Results : Vitamin D3 therapy in PCOS patients , increased serum vitamin D ( 7.00±2.80 to 22.9±6.14 ng/ml ) , decreased serum total cholesterol ( 196.6±32.8 to 179.1±34.1 mg/dl ) , triglyceride ( 156.8±73.0 to 130.5±56.5 mg/dl ) , and VLDL ( 31.4±14.6 to 26.1 ±11.3 mg/dl ) levels significantly ( p<0.05 ) , but it did not affect serum HDL-cholesterol , LDL-cholesterol , APO-AI , and hs-CRP concentrations . There was no change in variables in the placebo group . Conclusions : Our study showed that vitamin D3 therapy had beneficial effects on some CVD risk factors in PCOS patients with vitamin D deficiency . The trial was registered at I RCT .ir ( I RCT 138904113140N2 ) BACKGROUND Vitamin D testing is increasing worldwide . Recently several diagnostic manufacturers including Abbott and Siemens have launched automated 25-hydroxy vitamin D ( 25OH-D ) immunoassays . Furthermore , preexisting assays from DiaSorin and Roche have recently been modified . We compared the performance of 5 automated immunoassays , an RIA and 2 liquid chromatography-t and em mass spectrometry ( LC-MS/MS ) methods . METHODS Aliquots of 170 r and omly selected patient sample s were prepared and 25OH-D was measured by 2 LC-MS/MS methods , an RIA ( DiaSorin ) , and automated immunoassays from Abbott ( Architect ) , DiaSorin ( LIAISON ) , IDS ( ISYS ) , Roche ( E170 , monoclonal 25OH-D(3 ) assay ) , and Siemens ( Centaur ) . Within-run and between-run imprecision were evaluated by measurement of 5 replicates of 2 serum pools on 5 consecutive days . RESULTS The LC-MS/MS methods agreed , with a concordance correlation coefficient ( CCC ) of 0. 
    Output:
    
agent
***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: Insulin resistance is one of the most common features of polycystic ovary syndrome ( PCOS ) . Some studies suggest that vitamin D deficiency may have a role in insulin resistance ; thus , the aim of the current study was to determine the effect of vitamin D supplementation on insulin resistance in women with PCOS and a vitamin D deficiency . We hypothesized that vitamin D supplementation would lower the glucose level and insulin resistance in women with PCOS and a vitamin D deficiency . The current study was a r and omized , placebo-controlled , double-blinded trial with 50 women with PCOS and a vitamin D deficiency , 20 to 40 years old , assigned to receive 3 oral treatments consisting of 50,000 IU of vitamin D₃ or a placebo ( 1 every 20 days ) for 2 months ( vitamin D , n = 24 ; placebo , n = 26 ) . The fasting blood glucose , insulin , 25-hydroxyvitamin D , and parathyroid hormone levels , as well as the homeostasis model assessment of insulin resistance and quantitative insulin sensitivity check index were measured at baseline and after treatment . In the vitamin D group , the serum level of 25-hydroxyvitamin D increased ( 6.9 ± 2.8 to 23.4 ± 6.1 ng/mL , P < .0001 ) , and the parathyroid hormone level decreased ( 70.02 ± 43.04 to 50.33 ± 21.99 μ IU/mL , P = .02 ) . There were no significant changes in the placebo group . There was a significant increase in insulin secretion in the vitamin D group ( P = .01 ) , but this was not significant compared with the placebo group . The fasting serum insulin and glucose levels and the insulin sensitivity and homeostasis model assessment of insulin resistance did not change significantly by the end of the study . We were not able to demonstrate the effect of vitamin D supplementation on insulin sensitivity and insulin resistance in women with PCOS and vitamin D deficiency OBJECTIVE The objective of the study was to examine changes of 25-hydroxy-vitamin D ( 25OHD ) and PTH blood levels 4 and 20 wk after low-calorie diet-induced weight loss . METHODS Forty-four obese women [ aged 40.6 + /- 11.4 yr , body mass index ( BMI ) 36.7 + /- 4.9 kg/m(2 ) ] and 25 controls ( BMI 22.9 + /- 1.5 kg/m(2 ) ) were examined .  Anthropometric and cardiometabolic parameters and 25OHD and PTH levels  were determined at baseline and 4 and 20 wk after a low-calorie diet . RESULTS At baseline , 25OHD levels were lower in obese compared with control subjects ( 17 + /- 6.0 vs. 23.8 + /- 8.7 ng/ml , P < 0.001 ) , whereas no differences were found in PTH levels . In all women , a negative correlation was found between 25OHD levels and body weight ( BW ) ( r -0.32 , P < 0.001 ) , BMI ( r -0.37 , P < 0.001 ) , waist circumference ( r -0.26 , P < 0.05 ) , and percent fat mass ( r -0.38 , P = 0.001 ) as determined by bioelectrical impedance analysis . The 4-wk low-calorie diet ( n = 37 ) reduced BW and led to significant improvements in the homeostasis model assessment ( HOMA ) index and lipid levels . The 20-wk low-calorie diet ( n = 26 ) result ed in reduction of BW and BMI by 10 % , HOMA index ( 4.7 + /- 3.8 vs. 3.10 + /- 1.7 , P < 0.01 ) , and lipids levels ( except high density lipoprotein cholesterol ) and increase in 25OHD ( 15.4 + /- 6.0 vs. 18.3 + /- 5.1 ng/ml , P < 0.05 ) , compared with baseline . PTH levels were unchanged . The increase of 25OHD levels was associated with the reduction of insulin levels and HOMA index ( r -0.43 , P < 0.05 ) . CONCLUSIONS Blood 25OHD levels were low in obese women and correlated inversely with severity measures of obesity . Weight loss of 10 % after low-calorie diet increased 25OHD levels , and this increase was mainly associated with improvement of insulin resistance BACKGROUND It has been shown that many women with polycystic ovary syndrome ( PCOS ) are 25-hydroxyvitamin D ( 25OHD ) insufficient . Both statin treatment and vitamin D supplementation have been shown to improve biochemical hyper and rogenemia , insulin resistance , and markers of inflammation in patients with PCOS , raising the possibility that some of the statin effects are mediated through vitamin D. METHODS We conducted this r and omized , double-blind placebo controlled study to assess the effect of atorvastatin on serum 25OHD concentrations in patients with PCOS . Forty medication-naive patients with PCOS were r and omized to either atorvastatin 20 mg daily or placebo for 3 months . After completing the initial 3 months of atorvastatin or placebo , both groups of patients participated in a 3-month extension study with metformin 1500 mg daily . We measured changes in 25OHD concentrations by use of t and em mass spectrometry . RESULTS Mean ( SD ) baseline 25OHD concentrations were comparable between the 2 groups [ 45.9 ( 2.4 ) vs 44.8 ( 1.8 ) nmol/L ; P = 0.7 ] . There was a significant increase in 25OHD concentrations with atorvastatin [ 45.9 ( 2.4 ) vs 60.8 ( 3.5 ) nmol/L ] compared with placebo [ 44.8 ( 1.8 ) vs 41.8 ( 3.2 ) nmol/L ; P = 0.02 ] . Three-month treatment with metformin maintained the improvement of 25OHD  with atorvastatin compared to baseline [ 45.9 ( 2.4 ) vs 61.8 ( 3.5 ) , P ≤ 0.01 ) . There were no significant changes in 25OHD concentrations in the placebo group after 12 weeks of metformin . CONCLUSIONS Among patients with polycystic ovary syndrome , 12 weeks of atorvastatin led to a clinical ly significant rise in 25OHD concentrations . This may represent a beneficial pleiotropic effect of statins on 25OHD concentrations Vitamin D functions are not limited to skeletal health benefits and may extend to preservation of insulin secretion and insulin sensitivity . This review summarizes the literature related to potential vitamin D influences on glucose homeostasis and insulin sensitivity . Cross-sectional data provide some evidence that circulating 25-hydroxyvitamin D ( 25(OH)D ) is inversely associated with insulin resistance , although direct measurements of insulin sensitivity are required for confirmation . Reported associations with insulin secretion , however , are contradictory . Available prospect i ve studies support a protective influence of high 25(OH)D concentrations on type 2 diabetes mellitus risk . There is a general lack of consistency in vitamin D intervention outcomes on insulin secretion and sensitivity , likely due to differences in subject population s , length of interventions , and forms of vitamin D supplementation . Vitamin D receptor gene polymorphisms and vitamin D interactions with the insulin like growth factor system may further influence glucose homeostasis . The ambiguity of optimal vitamin D dosing regimens and optimal therapeutic concentrations of serum 25(OH)D limit available intervention studies . Future studies , including cross-sectional and prospect i ve , should be performed in population s at high risk for both vitamin D deficiency and type 2 diabetes mellitus . Well- design ed , placebo-controlled , r and omized intervention studies are required to establish a true protective influence of  vitamin D on glucose homeostasis Background : Polycystic ovary syndrome ( PCOS ) is the most common endocrine disorder in females of reproductive age . Insulin resistance is a frequent metabolic disturbance in PCOS . Vitamin D deficiency is a common problem . Accumulating evidence suggests that vitamin D has a role on insulin sensitivity so may contribute to reduction of hyper and rogenemia . Objective : The aim was to determine the effects of vitamin D treatment in metabolic components and ovulation evidence in PCOS . Material s and Methods : Fifty one untreated PCOS patients were r and omly divided into three groups and treated with calcitriol , metformin , or placebo . Before and 3 months after treatment , ovulation evidence was assessed by ovarian trans abdominal sonography . Plasma fasting glucose , insulin , homeostasis model assessment insulin resistance ( HOMA-IR ) , 25-hydroxyvitamin D , parathyroid hormone and and rogen levels were measured before and after treatment . A 75gr glucose test was performed before and after treatment and two set of results was compared . Results : Three patients did not continue this study . Only 11 patient ( 22.9 % ) had sufficient vitamin D levels ( > 30 ng/ml ) . Metformin caused a significant decrease in weight ( p=0.027 ) , insulin level ( p=0.043 ) , and insulin resistance ( p=0.048 ) . Systolic blood pressure and PTH significantly improved after calcitriol ( p=0.029 , p=0.009 respectively ) . An improvement in ovulation was detected after calcitriol and seven patients , without evidence of ovulation before treatment , illustrated ovulation after 3 months . Difference with calcitriol in ovulation was significant versus other two methods ( p=0.02 ) . Conclusion : Calcitriol treatment in PCOS may be prior to metformin in ovulation induction Background : Vitamin D deficiency is prevalent among women , including patients with polycystic ovary syndrome ( PCOS ) . Some studies have suggested that vitamin D may have a role in cardiovascular disease ( CVD ) . There is very limited data on the vitamin D effect on CVD risk factors in women with PCOS and vitamin D deficiency . Aim : To investigate the effect of cholecalciferol on CVD risk factors in PCOS women with vitamin D deficiency . Methods : The study was a r and omized , placebo-controlled , double blinded trial . Fifty PCOS women with vitamin D deficiency ( vitamin D , no.=24 ; placebo , no.=26 ) aged 20–40 yr , were r and omly assigned to receive 3 oral capsules of 50 , 000 IU vitamin D3 or a placebo ( one capsule every 20 days ) for two months . Serum vitamin D , PTH , lipid profile , apolipoprotein AI ( APO-AI ) , and high sensitive C- reactive protein ( hs-CRP ) were measured at baseline and after treatment . Results : Vitamin D3 therapy in PCOS patients , increased serum vitamin D ( 7.00±2.80 to 22.9±6.14 ng/ml ) , decreased serum total cholesterol ( 196.6±32.8 to 179.1±34.1 mg/dl ) , triglyceride ( 156.8±73.0 to 130.5±56.5 mg/dl ) , and VLDL ( 31.4±14.6 to 26.1 ±11.3 mg/dl ) levels significantly ( p<0.05 ) , but it did not affect serum HDL-cholesterol , LDL-cholesterol , APO-AI , and hs-CRP concentrations . There was no change in variables in the placebo group . Conclusions : Our study showed that vitamin D3 therapy had beneficial effects on some CVD risk factors in PCOS patients with vitamin D deficiency . The trial was registered at I RCT .ir ( I RCT 138904113140N2 ) BACKGROUND Vitamin D testing is increasing worldwide . Recently several diagnostic manufacturers including Abbott and Siemens have launched automated 25-hydroxy vitamin D ( 25OH-D ) immunoassays . Furthermore , preexisting assays from DiaSorin and Roche have recently been modified . We compared the performance of 5 automated immunoassays , an RIA and 2 liquid chromatography-t and em mass spectrometry ( LC-MS/MS ) methods . METHODS Aliquots of 170 r and omly selected patient sample s were prepared and 25OH-D was measured by 2 LC-MS/MS methods , an RIA ( DiaSorin ) , and automated immunoassays from Abbott ( Architect ) , DiaSorin ( LIAISON ) , IDS ( ISYS ) , Roche ( E170 , monoclonal 25OH-D(3 ) assay ) , and Siemens ( Centaur ) . Within-run and between-run imprecision were evaluated by measurement of 5 replicates of 2 serum pools on 5 consecutive days . RESULTS The LC-MS/MS methods agreed , with a concordance correlation coefficient ( CCC ) of 0. 
    Output:
    