Menstrual Cycle and Bone Health in Adolescents

[Contraception for adolescent : CNGOF Contraception guidelines]

OBJECTIVE

The goal is to establish dialogue and determine the needs and skill levels of adolescence. This concerns sexuality, the prevention of STIs, the informed choice of contraception to avoid an unplanned pregnancy. MéTHODES: A systematic review based on literature about contraception AND teenagers was performed using Pubmed, Cochrane, national and international recommendations.

RESULTS

The surveillance of the teenager contraception must integrate more specifically: global health with a stability of weight and corpulence, a sufficient calcium intake, the prevention of the sexually transmitted infections (STIs) and the vaccination against HPV. The 1st consultations with adolescent girls are an essential moment for dialogue in order to develop sexuality education. Main themes are: prevention of STIs with the use of condoms, detection of situations of precariousness or sexual abuse, and finally adherence to treatment to avoid unplanned pregnancy. Use of condoms associated with regular contraception is essential to assure a barrier against sexually transmitted infections (STIs) (NP1). To preserve the patient confidentiality, the patient is received alone (Grade B). She must be reassured about respect of anonymity and availability of free treatment. Clinical examination collects weight, height, BMI and blood pressure (Grade C). It is important to give them the choice of contraceptive method and provide objective information on the different contraceptive methods (NP2). If there are any contraindications, when the first prescription is a pill, it must be a 1st or 2nd generation pill with levonorgestrel. For some experts, it would be important to prescribe a pill at 30μg EE for better efficacy in case of forgetfulness in very young patients and for the good maintenance of bone mineralization (NP4). Information on long-acting reversible contraceptives, or LARCs, is essential. These contraceptive methods have proved their efficacy and their place in the first intention. (NP1).

CONCLUSION

Prescribing contraception to a teenage girl requires the adaptation of the best treatment to her needs to prevent an unwanted pregnancy. This requires good information on prevention of STIs and on different methods of contraception in a confidence climate.

Elevated serum soluble CD200 and CD200R as surrogate markers of bone loss under bed rest conditions

CD200 is a transmembrane protein that belongs to the immunoglobulin family of proteins and is ubiquitously expressed on a variety of cell types. Upon interaction with its receptors (CD200Rs) expressed on myeloid-derived cells and T lymphocytes, an immunoregulatory signal is delivered to receptor-expressing cells. Previous studies have implicated a role for CD200:CD200R in the regulation of the expression of mRNA markers of osteoclastogenesis/osteoblastogenesis, following interaction of CD200 (on osteoblast precursors) with CD200R1 (on osteoclast precursors). Signaling of CD200R1 is hypothesized to attenuate osteoclastogenesis. We have investigated whether levels of soluble forms of CD200 and/or CD200R1 (sCD200, sCD200R1) are altered in volunteers undergoing 6° head down tilt bed rest to mimic conditions of microgravity known to be associated with preferential osteoclastogenesis and whether countermeasures, reported to be beneficial in attenuation of bone loss under microgravity conditions, would lead to altered sCD200 and sCD200R1 levels. Our data suggest that, as predicted, sCD200 levels fall under bed rest conditions while sCD200R1 levels rise. In subjects undergoing 30-minute per day continuous centrifugation protocols, as a countermeasure to attenuate changes which may lead to bone loss, these alterations in sCD200 and sCD200R1 levels seen under conditions of bed rest were abolished or attenuated. Our results suggest that measurement of sCD200 and/or sCD200R1 may prove a useful and rapid means of monitoring subjects at risk of bone loss and/or accessing the efficacy of treatment regimes designed to counter bone loss.