However , subgroup analyses for the estrogen dose and the progestin type in relation to changes in SHBG levels did show significant differences : COCs containing second generation progestins and /or the lower estrogen doses ( 20–25 µg EE ) were found to have less impact on SHBG concentrations .
The current literature review and meta- analysis demonstrates that COCs decrease circulating levels of total T and free T and increase SBHG concentrations .
Due to the SHBG increase , free T levels decrease twice as much as total T. The estrogen dose and progestin type of the COC do not influence the decline of total and free T , but both affect SHBG .
BACKGROUND Combined oral contraceptives ( COCs ) reduce levels of and rogen , especially testosterone ( T ) , by inhibiting ovarian and adrenal and rogen synthesis and by increasing levels of sex hormone-binding globulin ( SHBG ) .
Although this suppressive effect has been investigated by numerous studies over many years , to our knowledge no systematic review concerning this issue had been performed .
Effect of four different oral contraceptives on various sex hormones and serum-binding globulins.
In a double-blind , controlled , r and omized , four-arm , bicentric clinical study , the effect of four oral contraceptives ( OCs ) on various hormone parameters and serum-binding globulins was investigated . Four groups with 25 volunteers each ( 18 - 35 years of age ) were treated for six cycles with monophasic combinations containing 21 tablets with either 30 microg ethinylestradiol ( EE ) + 2 mg dienogest ( DNG ) ( 30EE/DNG ) , 20 microg EE + 2 mg DNG ( 20EE/DNG ) , 10 microg EE + 2 mg estradiol valerate ( EV ) + 2 mg DNG ( EE/EV/DNG ) or 20 microg EE + 100 microg levonorgestrel ( LNG ) ( EE/LNG ) . The study was completed by 91 subjects . Blood sample s were taken after at least 12 h of fasting on Day 21 - 26 of the preceding control cycle and on Day 18 - 21 of the first , third and sixth treatment cycle . The serum concentrations of free testosterone were significantly decreased by about 40 - 60 % in all four groups , while those of dehydroepi and rosterone sulfate ( DHEAS ) showed a time-dependent decrease during treatment . Except for EE/EV/DNG , which increased prolactin significantly during the third and sixth cycles , no change was observed with the EE-containing preparations . There was a significant increase in the levels of serum-binding globulins during treatment , which differed according to the composition of the OCs used . The rise in sex hormone-binding globulin ( SHBG ) was highest during intake of 30EE/DNG ( + 320 % ) and lowest with EE/LNG ( + 80 % ) , while the effect of 20EE/DNG and EE/EV/DNG was similar ( + 270 % ) . The thyroxine-binding globulin ( TBG ) levels increased significantly , by 50 - 60 % , during treatment with the DNG-containing formulations , while the effect of EE/LNG was less significant ( + 30 % ) . The rise in corticosteroid-binding globulin ( CBG ) , which occurred in all groups , was most pronounced in women treated with 30EE/DNG ( + 90 % ) and least with EE/EV/DNG ( + 55 % ) , indicating a strong influence of EE and no effect of the progestogen component . In all treatment groups , the frequency of intracyclic bleeding rose in the first treatment cycle and decreased thereafter . Cycle control was significantly better with 30EE/DNG or EE/LNG than with 20EE/DNG or EE/EV/DNG . There was no significant change in blood pressure , body mass index or pulse rate throughout the study . In conclusion , the DNG-containing OCs caused a higher rise in SHBG and TBG levels than the LNG-containing preparation . The effects on CBG suggest a lesser hepatic effect of 2 mg EV as compared to 20 or 30 microg EE . In contrast to EE , the use of estradiol in OCs appeared to increase prolactin release , while the cycle control was better with the OC containing 30 microg EE
However , subgroup analyses for the estrogen dose and the progestin type in relation to changes in SHBG levels did show significant differences : COCs containing second generation progestins and /or the lower estrogen doses ( 20–25 µg EE ) were found to have less impact on SHBG concentrations .
The current literature review and meta- analysis demonstrates that COCs decrease circulating levels of total T and free T and increase SBHG concentrations .
Due to the SHBG increase , free T levels decrease twice as much as total T. The estrogen dose and progestin type of the COC do not influence the decline of total and free T , but both affect SHBG .
BACKGROUND Combined oral contraceptives ( COCs ) reduce levels of and rogen , especially testosterone ( T ) , by inhibiting ovarian and adrenal and rogen synthesis and by increasing levels of sex hormone-binding globulin ( SHBG ) .
Although this suppressive effect has been investigated by numerous studies over many years , to our knowledge no systematic review concerning this issue had been performed .