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 .
Effects of seven low-dose combined oral contraceptives on sex hormone binding globulin, corticosteroid binding globulin, total and free testosterone.
The effect of seven low-dose oral contraceptive preparations on sex hormone binding globulin ( SHBG ) , cortisol binding globulin ( CBG ) , total and absolute free testosterone were investigated in groups of 10 healthy volunteers . All preparations contained about the same amount of ethinylestradiol but they differed in type and /or dose of progestagen . The progestagens studied were : levonorgestrel ( LNG ; in mono- and triphasic preparations ) , norethisterone ( NET ; in monophasic preparation ) , desogestrel ( DSG ; in mono- and biphasic preparations ) and gestodene ( GSD ; in triphasic preparation ) , all 19-nortestosterone derivatives , and the anti- and rogen cyproterone acetate ( CPA ) in a monophasic preparation . Differences observed in SHBG level , which reflect the estrogen- and rogen balance , can be attributed to the intrinsic and rogenic ( or anti- and rogenic ) properties of the progestagens , and were in agreement with the results of published receptor binding studies , performed in vitro . Based on our results the following ranking ( high to low ) can be made with respect to the and rogenicity of the preparations : monophasic LNG greater than or equal to monophasic NET = triphasic LNG greater than or equal to triphasic GSD = biphasic DSG = monophasic DSG greater than monophasic CPA . An anti-estrogenic effect of the 19-nortestosterone derived progestagens can be excluded by the effect on CBG , a marker for estrogenic activity . All preparations containing a 19-nortestosterone derived progestagen , independent of their type and dose , induce a similar rise in CBG , whereas the preparation with cyproterone acetate induced an even higher CBG level . Irrespective of the effect on total testosterone , which varies between the preparations , the absolute free testosterone level decreased to a comparable degree for all preparations . ( ABSTRACT TRUNCATED AT 250 WORDS
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 .