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 .
Age-specific reference ranges for serum testosterone and androstenedione concentrations in women measured by liquid chromatography-tandem mass spectrometry.
OBJECTIVE RIA-based sex hormone measurements offer only limited precision and specificity in the low concentration range of women . Therefore , we aim ed to establish age-specific reference ranges for serum sex hormone concentrations in women using mass spectrometry and quantile regression . METHODS AND RESULTS Data from 985 women aged 20 - 80 yr , recruited for the prospect i ve Study of Health in Pomerania , were included in the analyses . Quantile regressions models were performed to calculate the age-specific 2.5th and 97.5th percentiles for sex hormone concentrations in women . Serum total testosterone ( TT ) and and rostenedione ( AD ) concentrations were measured by liquid chromatography-t and em mass spectrometry . Measured concentrations of SHBG and TT were used to calculate free testosterone ( free T ) . TT , AD , and free T concentrations showed a distinct age-related decline across 10-yr age groups ( one way ANOVA P < 0.001 ) . Sex hormone reference ranges for TT , AD , and free T were determined across each single year of age and for 10-yr age groups . Reference ranges over the whole age range of 20 - 80 yr were 0.35 - 1.97 nmol/liter for TT , 0.89 - 4.56 nmol/liter for AD , and 0.0025 - 0.0253 nmol/liter for free T. Separate reference ranges were provided for pre- and postmenopausal women as well as after inclusion of women using oral contraceptives or hormone therapy ( n = 1357 ) . CONCLUSION This is the first study to establish age-specific reference ranges for liquid chromatography-t and em mass spectrometry-measured  TT and AD and calculated free T concentrations based on quantile regression analyses , accurately accounting for the observed low concentration range and the strong age dependency of these sex hormones in women
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 .