Evaluación de la globulina transportadora de hormonas esteroidales (SHBG) durante el embarazo como factor predictor de pre-eclampsia y restricción del crecimiento intrauterino / Sex-hormone binding globulin (SHBG) levels during pregnancy as predictors for pre-eclampsia and fetal growth restriction

Background: Sex-Hormone Binding Globulin (SHBG) may be associated to Pre-eclampsia (PE) and Fetal Growth Restriction (RCIU). Aim: To determine if maternal serum SHBG concentrations during the first and second trimesters are predictive biomarkers of Pre-eclampsia and RCIU. Patients and Methods: Prospective cohort study carried out in the Fetal Medicine Unit, Universidad de Chile Clinical Hospital between January, 2005 and December, 2006. Blood samples were obtained from unselectedpregnant women during routine 11-14 week and 22-25 week ultrasound examinations, conforming two different study groups. Posteriorly, serum SHBG concentrations were determined in women who developed Pre-eclampsia, RCIU and their respective controls. Results: Fifty five patients were included in the 11-14 weeks group. Nine women that developed PE, 10 that developed RCIU and 36 controls were selected from this group. There were no significant differences in SHBG levels between patients with PE, RCIU or controls (324.7 (26.6), 336.8 (33.9) and 377.5 (24.3) nmol/L, respectively). Fifty four women were included in the 22-25 weeks group. Eight women who developed Pre-eclampsia, 15 who developed RCIU and 31 controls were selected. Again, there were no significant differences in SHBG levels between patients with PE, RCIU or controls (345.5 (151.1), 383.8 (143.4) and 345.5 nmol/l (151.1), respectively). Conclusions: Maternal SHBG serum levels did not predict subsequent development of Pre-eclampsia and RCIU.

Características clínicas e hormonais das pacientes com a síndrome dos ovários policísticos, em relaçäo à distribuiçäo de gordura corporal / Clinical and hormonal features in women with PCO according to body fat distribution pattern

Avaliar as características clínicas e laboratoriais das pacientes com Síndrome dos Ovários Policísticos (SOP) em funçäo da distribuiçäo de gordura corporal. Em 69 pacientes portadoras da SOP, divididas em dois grupos, um com distribuiçäo de gordura tipo ginecóide (Cintura/Quadril<8) (n=22) e outro com tipo androgênica (C/Q>0,8) (n=47), foram comparadas as freqüências da acne, hirsutismo, acantose nigricans, IMC, LH, FSH, PRL, T3, T4, TSH, T, glicemia e insulina de jejum, GTT, e curva de insulina. O IMC foi significativamente maior, e a acantose nigricans foi sete vezes mais freqüente nas pacientes com distribuiçäo de gordura androgênica (p=0,0001). Os níveis de insulina e de glicemia de jejum, de testosterona, os valores médios da glicemia e insulina, durante o teste de tolerância à glicose, foram maiores nas pacientes com distribuiçäo de gordura androgênica. Observamos um valor da área sob a curva significativamente maior no grupo das pacientes com distribuiçäo androgênica. A resposta insulinêmica e glicêmica, frente ao teste de estímulo com dextrasol foi significativamente maior nas pacientes portadoras da SOP com distribuiçäo de gordura tipo androgênica.

Efecto metabólico en la posmenopausia de un esteroide sintético (tibolona) con acción estrogénica característica / Metabolic effects in post-menopause of a synthetic steroid (tibolone) with a characteristic estrogenic effect

En vista de que la esperanza de vida de las mujeres de ha prolongado hasta cerca de los 80 años, el período postmenopáusico ha cobrado un gran interés, de manera particular en lo referente a las ventajas de utilizar la terapia de reemplazo hormonal (TRH). En la actualidad existen múltiples opciones terapéuticas con el objeto de evitar o minimizar efectos indeseables de los fármacos con actividad estrogénica. Una de las modalidades es un esteroide sintético (tibolona) que ejerce una acción moderada tanto estrogénica como andrógeno-progestagénica y aparentemente no requiere convertirse a "estradiol". En el presente trabajo se estudiaron varios índices metabólicos y hormonales para determinar el efecto de la administración de tibolona por vía oral a la dosis de 2.5 mg durante 6 meses. Aunque los niveles circulantes de estradiol no se modificaron, se observó una disminución en las concentraciones de FSH, colesterol total, lipoproteínas de baja densidad y triglicéridos. Por otra parte se observó un incremento en los niveles de lipoproteínas de alta densidad y de la globulina transportadora de hormonas sexuales (SHBG). Estos efectos metabólicos se suman y explican las observaciones de los estudios clínicos previos que habían mostrado un efecto leve sobre glándula mamaria, endometrio y peso corporal

Biologically active steroid and thyroid hormones stimulate secretion of sex hormone-bending globulin by human term placenta in culture

In this study, the influence of steroid and thyroid hormones and epidermal growth factor on the productin of SHBG by placenta tissue explants was investigated. Explants of trophoblastic tissue obtained from normal term placentas were cultured for 48 h in serum free culture medium, and then for an additional 24 h period in the presence or absence of various concentrations of either estradiol (0.25 - 5 nM), testoterone (0.5 - 500 nM), triiodothyronine (0.01 - 100 nM) or EGF (2-40 µM), respectively. Human SHBG concentration in culture media was estimated on each day by specific two-site time-resolved fluoroimmunometric assay and the results expressed as pmol/mg tissue protein. Binding characteristics and molecular structure of secreted SHBG were determined by [3H]5a-DHT binding assays and Western blot analysis, espectively. Estradiol and triidothyronine but not testoterone increased significantly (p<0.05 vs. control) the secretion of SHBG into the culture media. Addition of EGF did not significantly change the production of SHBG at the various concentrations studied. [3H]5a-DHT binding assays and Western blot analysis of placental SHBG resulted in identical binding affinities (Kd 2.0 ñ 0.16 x 10-9M= and molecular structure to those obtained in serum from normal pregnant women. These findings support and extend previous observations by our laboratory indicating that SHBG gene is expressed in the placenta and provide further evidence on the hormonal regulatory characteristics of this steroid-binding protein in cultured placenta

The effect of oral contraceptives on protein metabolism.

The effect on protein and amino acid metabolism of combined oral contraceptives (OC) containing 150 micrograms of laevonorgestrel and 30 micrograms of ethinyl oestradiol was studied in a group of 34 healthy non-lactating women. This was compared to an identical study conducted in another group of 19 subjects who used IUCDs for contraception, and also in two other groups of subjects who were given an additional multivitamin preparation on a daily basis (29 subjects) and on the days when OC was not taken (29 subjects). Assessments were made prior to, and during the third week of the 4th, 7th, and the 13th cycles of OC treatment. Results indicated that the ceruloplasmin and retinol binding protein underwent significant increases with OC usage, while sex hormone binding globulin concentration, on the other hand, remained unaffected. At the same time, a significant reduction of several of the plasma amino acid and plasma albumin concentrations was observed, suggesting that the increase in the visceral and other types of protein concentrations previously noted was due to increased hepatic protein synthesis rather than increased breakdown or excretion as result of OC intake. Interesting biochemical alterations and metabolic effects previously observed may well be related to this altered synthesis and release of proteins and/or protein binders as well as induction of certain metabolic enzymes from the liver.

Changes in the distribution of testosterone and estradiol serum fractions in hirsute women after administration of L-Thyroxine

La concentración sérica de la globulina ligadora de hormonas sexuales (SHBG) es dependiente del medio hormonal. Los estrógenos y las hormonas tireoideas aumentan los niveles mientras que los andrógenos y la hormona de crecimiento los disminuyen. El hirsutismo se asocia frecuentemente con una disminución de la SHBC sérica y un aumento de las testosterona (T) libre (L) y de la T no unida a SHBG (T no-u-SHBG) o biodisponible. Dado que la hormona tiroidea aumenta los niveles séricos de la hormona SHBG, se estudió en 10 mujeres adultas sin sobrepeso corporal con hirsutismo el efecto del tratamiento con 1-tiroxina (L-T4). La edad cronológica fue 22 ñ 2,7 años (media + DS). Cuatro pacientes presentaron síndrome de poliquistosis ovárica, 6 hirsutismo idiopático de las cuales 2 tenían oligomenorrea. Los estudios hormonales fueron realizados antes y después de un mes de tratamiento con L-T4 a una dosis de 2 microng/Kg de peso corporal. Se midieron los niveles séricos de SHBG por análisis de saturación y la testosterona (T), estradiol (E2), androstenediona, dehidroepiandrosterona (DHAS), LH, FSH, PRL, T4, T3, TSH por RIA, y se calcularon las fracciones séricas de T y E2 utilizando una ecuación matemática derivada de la ley de acción de masas. Se observaron los siguientes cambios antes y después, respectivamente (X ñ ES); SHBG 30,3 ñ 3,8 y 45,3 ñ 4,6 nmol/l (P<0,001), T n-u-SHBG 25,7 ñ 8,1 y 18,8 ñ 6 ng/dl (P<0,001), T libre 1,09 ñ 0,2 y 0,8 ñ 0,5 ng/dl (P<0,01) (Fig. 1), E2 no-u-SHBG 40,9...

Normalization of serum sex hormone-binding globulin by L-thyroxine in obese women

La obesidad se asocia con disminución de los niveles séricos de SHBC cuyo origen se desconoce. Se bien las mujeres obesas no presentan evidencias bioquímicas de disminución de la función tiroidea, dado que las hormonas tiroideas aumentan los niveles séricos de la SHBG, se estudió en un grupo de mujeres con obesidad moderada la respuesta de esta proteína a la administración de hormona tiroidea (1-T4). La SHBG sérica aumentó de 44,9 ñ 14,2 (media ñ ES) a 77 ñ 139 nmol/l en 10 mujees obesas luego del tratamiento durante 1 mes con 1-T4 a ladosis de 2,25 ñ 0,58 microng/Kg de peso corporal (p < 0,01). No se observaron cambios en los niveles séricos de la SHBG en mujeres normales con tratamiento similar, mientras que los valores obtenidos en un grupo de pacientes hipotiroideas fueron de 24,2 ñ 3,2 y 60 ñ 9,26 nmol/l, respectivamente (p < 0,01) (Fig. 1). Los niveles de T4 y T3 bajo 1-T4 fueron normales en los 3 grupos de pacientes, así como los niveles séricos de la T4 libre en las obesas. Dado que el comportamiento de las obesas fue similar al de los sujetos hipotiroideos, se especula la posibilidad de que pueda existir una disfunción tiroidea hepática que justifique en parte la disminución de los niveles séricos de la SHBG que se observan en la obesidad. Independientemente del mecanismo, nosotros hemos hallado que los niveles séricos de la SHBG en las mujeres obesas pueden se normalizados luego de la administración de dosis fisológicas de hormona tiroidea