RESUMO

BACKGROUND: Tamoxifen is considered a prodrug of its active metabolite endoxifen, which is dependent on the CYP2D6 and CYP3A enzymes. Tamoxifen pharmacokinetic variability influences endoxifen exposure and, consequently, its clinical outcome. This study investigated the impact of hormonal status on the pharmacokinetics of tamoxifen and its metabolites in TAM-treated breast cancer patients. METHODS: TAM-treated breast cancer patients (n = 40) previously believed to have CYP3A activity within the normal range based on oral midazolam and phenotyped as CYP2D6 normal metabolizers using oral metoprolol were divided into two groups according to premenopausal (n = 20; aged 35-50 years) or postmenopausal (n = 20; aged 60-79 years) status. All patients were treated with 20 mg/day tamoxifen for at least three months. Serial plasma samples were collected within the 24 h dose interval for analysis of unchanged tamoxifen, endoxifen, 4-hydroxytamoxifen and N-desmethyltamoxifen quantified by LC-MS/MS. CYP activities were assessed using midazolam apparent clearance (CYP3A) and the metoprolol/alfa-hydroxymetoprolol plasma metabolic ratio (CYP2D6). CYP3A4, CYP3A5 and CYP2D6 SNPs and copy number variation were investigated using TaqMan assays. RESULTS: Postmenopausal status increased steady-state plasma concentrations (Css) of tamoxifen (116.95 vs 201.23 ng/mL), endoxifen (8.01 vs 18.87 ng/mL), N-desmethyltamoxifen (485.16 vs 843.88 ng/mL) and 4-hydroxytamoxifen (2.67 vs 4.11 ng/mL). The final regression models included hormonal status as the only predictor for Css of tamoxifen [ß-coef ± SE, p-value (75.03 ± 17.71, p = 0.0001)] and 4-hydroxytamoxifen (1.7822 ± 0.4385, p = 0.0002), while endoxifen Css included hormonal status (8.578 ± 3.402, p = 0.02) and race (11.945 ± 2.836, p = 0.007). For N-desmethyltamoxifen Css, the final model was correlated with hormonal status (286.259 ± 76.766, p = 0.0007) and weight (- 8.585 ± 3.060, p = 0.008). CONCLUSION: The premenopausal status was associated with decreased endoxifen plasma concentrations by 135% compared to postmenopausal status. Thus, the endoxifen plasma concentrations should be monitored mainly in the premenopausal period to maintain plasma levels above the efficacy threshold value. TRIAL REGISTRATION: RBR-7tqc7k.

Assuntos

RESUMO

OBJECTIVES: To assess the correlation between hormonal status and pelvic floor muscle strength. METHODS: A total of 140 continent women were prospectively evaluated, and divided into four groups according to age: group 1 (n = 34) aged 30-40 years; group 2 (n = 38) aged 41-50 years; group 3 (n = 35) aged 51-60; and group 4 (n = 33) aged >60 years. The following parameters were evaluated: demographic data using clinical questionnaire; hypermobility of the bladder neck using swab test; vaginal trophism by gynecological examination; hormonal status of the vagina by cytology; and pelvic floor muscle strength using a perineometer and electromyography. RESULTS: There were no statistical differences between pelvic floor muscle strength, demographic characteristics, vaginal trophism and hypermobility of the bladder neck between groups (P > 0.05). There was a larger number of women with vaginal atrophy among those aged >60 years. Vaginal trophism assessed by pelvic examination was highly consistent with the findings of colpocytology (kappa test = 0.888). Electromyography showed that women with hypermobility had lower muscle resistance (endurance) when compared with those without hypermobility. CONCLUSIONS: Although vaginal atrophy is more intense in women aged >60 years, no difference can be found in the pelvic floor muscle strength during the physiological aging process in continent women. As a consequence, trophism is not the only factor related to pelvic floor muscle strength, and it should not preclude the selection of patients who are referred to prophylaxis.

Assuntos

RESUMO

En una población de pacientes con artritis reumatoidea (AR) se estudió la relación de esta patología con el tabaquismo, su perfil hormonal, la concentración de interleuquina 6 (IL 6) y la coexistencia de fibromialgia. Casi en el 50% de los pacientes, los valores de IL 6 fueron seis veces superiores al valor considerado normal. El hábito del tabaco, la edad y el tipo de tratamiento no influyeron en los valores de IL 6. En el subgrupo de pacientes con fibromialgia se observaron tanto altos niveles de IL 6 como bajos niveles de dehidroepiandrosterona (DHEA).

The relation between rheumatoid arthritis and smoking habits, hormonal status, interleuquin-6 levels and fibromyalgia in a population of patients was analyzed. Almost 50% showed IL6 values six times higher than the normal level. Smoking habits, age and the type of treatment did not influence IL-6 concentrations. Patients with fibromyalgia had high levels of IL6 as well as low dehydroepiandrosterone values.

Estuda-se numa população de pacientes com artrite reumatóide a relação desta patologia com o tabagismo, seu perfil hormonal, a concentração de interleucina 6 e a coexistência de fibromialgia. Quase no 50% dos pacientes os valores de IL 6 foram seis vezes superiores ao valor considerado normal. O hábito de fumar, a idade e o tipo de tratamento não influíram nos valores de IL 6. No subgrupo de pacientes com fibromialgia observa-se tanto altos níveis de IL 6 como baixos níveis de DHEA.

Assuntos

RESUMO

En una población de pacientes con artritis reumatoidea (AR) se estudió la relación de esta patología con el tabaquismo, su perfil hormonal, la concentración de interleuquina 6 (IL 6) y la coexistencia de fibromialgia. Casi en el 50% de los pacientes, los valores de IL 6 fueron seis veces superiores al valor considerado normal. El hábito del tabaco, la edad y el tipo de tratamiento no influyeron en los valores de IL 6. En el subgrupo de pacientes con fibromialgia se observaron tanto altos niveles de IL 6 como bajos niveles de dehidroepiandrosterona (DHEA).(AU)

The relation between rheumatoid arthritis and smoking habits, hormonal status, interleuquin-6 levels and fibromyalgia in a population of patients was analyzed. Almost 50% showed IL6 values six times higher than the normal level. Smoking habits, age and the type of treatment did not influence IL-6 concentrations. Patients with fibromyalgia had high levels of IL6 as well as low dehydroepiandrosterone values.(AU)

Estuda-se numa populaþÒo de pacientes com artrite reumatóide a relaþÒo desta patologia com o tabagismo, seu perfil hormonal, a concentraþÒo de interleucina 6 e a coexistÛncia de fibromialgia. Quase no 50% dos pacientes os valores de IL 6 foram seis vezes superiores ao valor considerado normal. O hábito de fumar, a idade e o tipo de tratamento nÒo influíram nos valores de IL 6. No subgrupo de pacientes com fibromialgia observa-se tanto altos níveis de IL 6 como baixos níveis de DHEA.(AU)