BACKGROUNDCombined oral contraceptives (COCs) reduce levels of androgen, especially testosterone (T), by inhibiting ovarian and adrenal androgen 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. This systematic review and meta-analysis was performed to evaluate the effect of COCs on concentrations of total T, free T and SHBG in healthy women and to evaluate differences between the various types of COCs (e.g. estrogen dose, type of progestin) and the assays used to assess total T and free T.METHODSA review of the literature was performed using database searches (MEDLINE, EMBASE and the Cochrane Central Register of Clinical Trials) and all publications (from inception date until July 2012) investigating the effect of COCs on androgen levels in healthy women were considered eligible for selection. Three reviewers were involved in study selection, data extraction and critical appraisal. For the meta-analysis, data on total T, free T and SHBG were extracted and combined using random effects analysis. Additional subgroup analyses were performed to evaluate differences between the various types of COCs (e.g. estrogen dose, type of progestin) and the assays used to assess total T or free T.RESULTSA total of 151 records were identified by systematic review and 42 studies with a total of 1495 healthy young women (age range: 18–40 years) were included in the meta-analysis. All included studies were experimental studies and 21 were non-comparative. Pooling of the results derived from all the included papers showed that total T levels significantly decreased during COC use [mean difference (MD) (95% confidence interval, CI) −0.49 nmol/l (−0.55, −0.42); P < 0.001]. Significantly lower levels of free T were also found [relative change (95% CI) 0.39 (0.35, 0.43); P < 0.001], with a mean decrease of 61%. On the contrary, SHBG concentrations significantly increased during all types of COC use [MD (95% CI) 99.08 nmol/l (86.43, 111.73); P < 0.001]. Subgroup analyses revealed that COCs containing 20–25 µg EE had similar effects on total and free T compared with COCs with 30–35 µg EE. In addition, suppressive effects on T levels were not different when comparing different types of progestins. 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.CONCLUSIONSThe 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. The clinica...

Twenty consecutive patients with the clinical suspicion of a perianal fistula were studied to define the optimal and time-efficient imaging planes for endoanal MRI in the identification and classification of perianal fistulas. The duration of each part of the MR procedure was recorded in all patients. Off-axis axial (A), coronal (C), sagittal (S) and radial (R) T2-weighted sequences were performed in all patients. Sets of images and combinations of images (A; R; CS; AR; ACS; ARCS) without patient data were reviewed in masked fashion and independently with a 2-month interval between each set. The reader was masked to the results of previous readings. The findings were compared with the surgical findings. The number of correctly identified and classified fistula and the sensitivity and specificity were determined. Twenty fistulas were present at surgery: 14 transsphincteric fistulas and six intersphincteric fistulas. Eighteen fistulas were correctly identified with the radial (R) and combined coronal sagittal (CS) sequences. In all other sequences or combinations of sequences all 20 fistulas were identified. Classification was correct with A in 16 patients, with R in 15, with CS in 15, with AR in 18, with ACS in 17 and with ARCS in 18. The sensitivity and specificity were optimal using AR or ARCS (0. 86 and 1 respectively). The optimal and most time-efficient imaging protocol for endoanal MRI of perianal fistulas thus comprises the axial and radial imaging planes.