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1.
Phys Med Biol ; 67(7)2022 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-35272282

RESUMO

Objective. A novel treatment modality is currently being developed that produces converging monoenergetic x-rays. Conventional application of dosimetric calibration as presented in protocol TG61 is not applicable. Furthermore, the dosimetry of the focal point of the converging beam is on the order of a few millimeters, requiring a high-resolution dosimeter. Here we present a procedure to calibrate radiochromic film for narrow-beam monoenergetic 60 keV photons as well as absolute dosimetry of monoenergetic focused x-rays. A study of the focal spot dose rate after passing through a bone-equivalent material was also done to quantify the effects of heterogeneous materials.Approach.This was accomplished by configuring a polyenergetic beam of equivalent energy using a clinical orthovoltage machine. Calibrated films were then used to perform absolute dosimetry of the converging beam by measuring the beam profile at various depths in water. Main Results.A method for calibrating radiochromic film has been developed and detailed that allows absolute dosimetry of a monoenergetic photon beam. Absolute dosimetry of a focused, mono-energetic beam resulted in a focal spot dose rate of ∼30 cGy min-1at a depth of 5 cm in water.Significance.This work serves to establish a dosimetry protocol for mono-energetic beam absolute dosimetry as well as the use of such a method for measurement of a novel teletherapy modality.


Assuntos
Dosimetria Fotográfica , Radiometria , Calibragem , Dosimetria Fotográfica/métodos , Fótons/uso terapêutico , Radiometria/métodos , Água
2.
Sci Rep ; 11(1): 19180, 2021 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-34584192

RESUMO

We describe the development and analysis of a new teletherapy modality that, through a novel approach to targeted radiation delivery, has the potential to provide greater conformality than conventional photon-based treatments. The proposed system uses an X-ray lens to reflect photons from a conventional X-ray tube toward a focal spot. The resulting dose distributions have a highly localized peak dose, with lower doses in the converging radiation cone. Physical principles governing the design of this system are presented, along with a series of measurements analyzing various characteristics of the converging beam. The beam was designed to be nearly monoenergetic (~ 59 keV), with an energy bandwidth of approximately 10 keV allowing for treatment energies lower than conventional therapies. The focal spot was measured to be approximately 2.5 cm long and 4 mm wide. Mounting the proposed X-ray delivery system on a robotic arm would allow sub-millimeter accuracy in focal spot positioning, resulting in highly conformal dose distribution via the optimal placement of individual focal spots within the target volume. Aspects of this novel radiation beam are discussed considering their possible clinical application as a treatment approach that takes maximum advantage of the unique properties afforded by converging X-ray beam therapy.


Assuntos
Lentes , Fótons/uso terapêutico , Radioterapia Conformacional/instrumentação , Desenho de Equipamento , Humanos , Método de Monte Carlo , Imagens de Fantasmas , Radiometria , Dosagem Radioterapêutica
5.
Obstet Gynecol ; 121(3): 593-600, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23635623

RESUMO

OBJECTIVE: Depot medroxyprogesterone acetate (DMPA) reversibly reduces bone mineral density. To estimate the extent to which DMPA might increase fracture risk, we undertook a retrospective cohort study of fractures in DMPA users and users of non-DMPA contraceptives, using the General Practice Research Database. METHODS: Eligible women were aged younger than 50 years at the qualifying first contraceptive prescription. The DMPA users were classified by DMPA exposure (cumulative and time of last dose) based on prescription records. All incident fractures were included; fracture incidence and risk factors before starting contraceptive use (DMPA or other) also were estimated. RESULTS: We identified 11,822 fractures in 312,395 women during 1,722,356 person-years of follow-up. Before contraceptive use started, DMPA users had higher fracture risk than nonusers (incidence rate ratio 1.28, 95% confidence interval [CI] 1.07-1.53). After DMPA started, crude fracture incidence was 9.1 per 1,000 person-years for DMPA users and 7.3 for nonusers (crude incidence rate ratio 1.23, 95% CI 1.16-1.30). Fracture risk in DMPA users did not increase after starting DMPA (incidence rate ratio after or before 1.08, 95% CI 0.92-1.26). There was little confounding by age or other factors that could be measured. Fracture incidence was 9.4 per 1,000 person-years in low-exposure DMPA users, and 7.8 per 1,000 in high-exposure DMPA users. The DMPA users had higher fracture risk than nonusers at the start of contraceptive use, with no discernible induction period. CONCLUSION: Although DMPA users experienced more fractures than nonusers, this association may be the result of confounding by a pre-existing higher risk for fractures in women who chose DMPA for contraception.


Assuntos
Anticoncepcionais Femininos/efeitos adversos , Fraturas Ósseas/induzido quimicamente , Acetato de Medroxiprogesterona/efeitos adversos , Adolescente , Adulto , Anticoncepcionais Femininos/administração & dosagem , Preparações de Ação Retardada , Feminino , Fraturas Ósseas/epidemiologia , Humanos , Incidência , Acetato de Medroxiprogesterona/administração & dosagem , Pessoa de Meia-Idade , Estudos Retrospectivos , Reino Unido/epidemiologia , Adulto Jovem
6.
Expert Opin Pharmacother ; 13(15): 2157-70, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22984937

RESUMO

INTRODUCTION: Dysmenorrhea is the most common gynecologic complaint among adolescents/young adults. Dysmenorrhea is usually primary and is associated with normal ovulatory cycles and with no pelvic pathology. Potent prostaglandins and potent leukotrienes play an important role in generating primary dysmenorrhea symptoms. Adolescents/young adults with severe dysmenorrhea symptoms may have pelvic abnormalities, such as endometriosis or uterine anomalies (secondary dysmenorrhea). AREAS COVERED: This review provides an update on treatments and management strategies of dysmenorrhea in adolescents/young adults. Medical literature articles were retrieved using a Medline search on primary and secondary dysmenorrhea. Original articles from peer-reviewed journals were selected based on relevance. EXPERT OPINION: Treatment with nonsteroidal anti-inflammatory drugs (NSAIDs) is the preferred initial treatment for dysmenorrhea in nonsexually active adolescents/young adults. Adolescents/young adults with symptoms that do not respond to NSAIDs for three menstrual periods should be offered hormonal treatment, such as combined estrogen and progestin oral contraceptive pills (OCPs), for three menstrual cycles. If dysmenorrhea does not improve within 6 months of NSAIDs and OCPs, a laparoscopy is indicated to look for endometriosis, which is the most common reason for secondary dysmenorrhea.


Assuntos
Dismenorreia/tratamento farmacológico , Adolescente , Anti-Inflamatórios não Esteroides/uso terapêutico , Anticoncepcionais Orais/uso terapêutico , Dismenorreia/metabolismo , Endometriose/tratamento farmacológico , Endometriose/cirurgia , Feminino , Humanos , Adulto Jovem
7.
J Pediatr Adolesc Gynecol ; 25(4): 259-61, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22840936

RESUMO

STUDY OBJECTIVE: The objective of this study was to evaluate methods of initial diagnosis and management of polycystic ovary syndrome (PCOS) among members of the North American Society for Pediatric and Adolescent Gynecology (NASPAG) to assess the degree of practice heterogeneity among specialist providers of adolescent care. DESIGN: Cross-sectional, anonymous, internet survey PARTICIPANTS: NASPAG membership (N = 326; Respondents = 127 (39%)) RESULTS: Percentage of respondents who incorporated specific tests at initial diagnosis was highly variable ranging from 87% (thyroid stimulating hormone) to 17% (sex hormone binding globulin). Oral contraceptives and diet modification/exercise were the most common therapies recommended by 98% and 90% of respondents respectively. CONCLUSION: Considerable practice heterogeneity was present with regards to diagnostic testing for suspected PCOS. Recommendations for first-line therapy were more consistent. Future studies should clarify the clinical utility of specific diagnostic tests for adolescents, such that selection of diagnostic testing is evidence based.


Assuntos
Síndrome Metabólica/diagnóstico , Síndrome do Ovário Policístico/diagnóstico , Síndrome do Ovário Policístico/terapia , Padrões de Prática Médica , Adolescente , Anticoncepcionais Orais/uso terapêutico , Estudos Transversais , Coleta de Dados , Exercício Físico , Comportamento Alimentar , Feminino , Hormônios/sangue , Humanos , Hipoglicemiantes/uso terapêutico , Síndrome Metabólica/complicações , Metformina/uso terapêutico , Antagonistas de Receptores de Mineralocorticoides/uso terapêutico , Síndrome do Ovário Policístico/complicações , Encaminhamento e Consulta , Globulina de Ligação a Hormônio Sexual , Espironolactona/uso terapêutico
8.
J Adolesc Health ; 48(5): 448-52, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21501802

RESUMO

PURPOSE: To explore the prevalence of low vitamin D status among obese adolescents and to examine the effect of current management of low vitamin D status in these patients. METHODS: A retrospective chart review of obese adolescents who had been screened for vitamin D status by serum total 25-hydroxyvitamin D (25(OH)D) level. Vitamin D deficiency was defined as 25(OH)D level of <20 ng/mL, vitamin D insufficiency as 25(OH)D level of 20-30 ng/mL, and vitamin D sufficiency as 25(OH)D level of >30 ng/mL. Adolescents with vitamin D deficiency were treated with 50,000 IU of vitamin D once a week for 6-8 weeks, whereas adolescents with vitamin D insufficiency were treated with 800 IU of vitamin D daily for 3 months. Repeat 25(OH)D was obtained after treatment. RESULTS: The prevalence rate of low vitamin D status among 68 obese adolescents (53% females, 47% males, age: 17 ± 1 years, body mass index: 38 ± 1 kg/m(2), Hispanic: 45%, African American: 40%, Caucasian: 15%) was 100% in females and 91% in males. Mean (±SE) 25(OH)D level was significantly higher in summer (20 ± 8 ng/mL) than in spring (14 ± 4 ng/mL, p < .02), and significantly lower in winter (15 ± 7 ng/mL) than in fall (25 ± 15 ng/mL, p < .05). Although there was a significant (p < .00001) increase in mean 25(OH)D after the initial course of treatment with vitamin D, 25(OH)D levels normalized in only 28% of the participants. Repeat courses with the same dosage in the other 72% did not significantly change their low vitamin D status. CONCLUSIONS: Increased surveillance and possibly higher vitamin D doses are warranted for obese adolescents whose total 25(OH)D levels do not normalize after the initial course of treatment.


Assuntos
Obesidade , Avaliação de Resultados em Cuidados de Saúde , Deficiência de Vitamina D/dietoterapia , Deficiência de Vitamina D/epidemiologia , Adolescente , Suplementos Nutricionais , Feminino , Humanos , Masculino , Auditoria Médica , Estudos Retrospectivos , Rhode Island/epidemiologia
9.
Contraception ; 82(6): 503-12, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21074012

RESUMO

BACKGROUND: It is unclear why some adolescents experience substantial bone mineral density (BMD) loss, while others experience a minimal decrease during depot medroxyprogesterone acetate (DMPA) use. We examined biopsychosocial factors in adolescents who experienced ≥5% BMD loss from baseline compared with adolescents who experienced <5% BMD loss during DMPA use. STUDY DESIGN: A multicenter, prospective, nonrandomized study of 181 female adolescents who initiated DMPA for contraception was conducted. BMD (by dual-energy X-ray absorptiometry) and serum estradiol were measured at initiation and every 6 months for 240 weeks of DMPA use. RESULTS: Half of participants experienced BMD loss of ≥5% from baseline at the hip, and a quarter experienced BMD loss of ≥5% at the lumbar spine (BMD substantial losers, SL). Hip and lumbar spine BMD-SL received a significantly greater number of DMPA injections than non-SL (p<.001). Decreased estradiol levels did not statistically differ between BMD loss subgroups. Hip BMD-SL had significantly lower baseline body mass index (BMI) than non-SL (p=.002), and there was an inverse relationship between weight gain and degree of BMD loss. Mean calcium intake was significantly lower (p<.05) in hip BMD-SL, and reported alcohol use was significantly higher (p<.05) in lumbar spine BMD-SL compared with non-SL. CONCLUSIONS: BMD loss of ≥5% was more common at the hip than at the lumbar spine among adolescents using DMPA. Decreased serum estradiol levels did not correlate with magnitude of BMD loss. Lower BMI and calcium intake and greater alcohol use were associated with greater BMD loss in adolescents using DMPA.


Assuntos
Densidade Óssea/efeitos dos fármacos , Anticoncepcionais Femininos/efeitos adversos , Acetato de Medroxiprogesterona/efeitos adversos , Adolescente , Consumo de Bebidas Alcoólicas/fisiopatologia , Consumo de Bebidas Alcoólicas/psicologia , Criança , Estudos de Coortes , Anticoncepcionais Femininos/administração & dosagem , Preparações de Ação Retardada , Estradiol/sangue , Feminino , Articulação do Quadril/efeitos dos fármacos , Humanos , Vértebras Lombares/efeitos dos fármacos , Acetato de Medroxiprogesterona/administração & dosagem , Estudos Prospectivos , Fumar/fisiopatologia , Fumar/psicologia
10.
Contraception ; 81(4): 281-91, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20227543

RESUMO

BACKGROUND: Depot medroxyprogesterone acetate (DMPA) is a highly effective progestin-only contraceptive that is widely used by adolescents. We investigated bone mineral density (BMD) changes in female adolescents during and following use of this method. STUDY DESIGN: A multicenter, prospective, non-randomized observational study in 98 healthy female adolescents aged 12-18 years who initiated DMPA intramuscular injections for contraception and provided BMD data for up to 240 weeks while receiving DMPA and for up to 300 weeks after DMPA cessation. BMD at the lumbar spine (LS), total hip (TH) and femoral neck (FN) was assessed by dual-energy X-ray absorptiometry. A mixed model analysis of variance was used to examine BMD changes. RESULTS: At the time of their final DMPA injection, participants had mean BMD declines from baseline of 2.7% (LS), 4.1% (TH) and 3.9% (FN) (p<.001 at all three sites). Within 60 weeks of discontinuation of DMPA, mean LS BMD had returned to baseline levels, and 240 weeks after DMPA discontinuation, the mean LS BMD was 4.7% above baseline. Mean TH and FN BMD values recovered to baseline values more slowly: 240 weeks and 180 weeks, respectively, after the last DMPA injection. CONCLUSIONS: BMD loss in female adolescents receiving DMPA for contraception is substantially or fully reversible in most girls following discontinuation of DMPA, with faster recovery at the LS than at the hip.


Assuntos
Densidade Óssea/efeitos dos fármacos , Anticoncepcionais Orais Sintéticos/efeitos adversos , Acetato de Medroxiprogesterona/efeitos adversos , Gravidez na Adolescência/prevenção & controle , Adolescente , Consumo de Bebidas Alcoólicas/efeitos adversos , Índice de Massa Corporal , Criança , Anticoncepcionais Orais Sintéticos/administração & dosagem , Preparações de Ação Retardada/administração & dosagem , Preparações de Ação Retardada/efeitos adversos , Feminino , Humanos , Estudos Longitudinais , Acetato de Medroxiprogesterona/administração & dosagem , Gravidez , Estudos Prospectivos , Fumar/efeitos adversos
11.
J Pediatr Adolesc Gynecol ; 23(1): 23-31, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19647454

RESUMO

OBJECTIVE: To date, there are no data regarding the effect of the transdermal combined estrogen and progestin contraceptive Ortho Evra on bone mineral content (BMC) and bone mineral density (BMD). We examined the effects of transdermally delivered ethinyl estradiol and norelgestromin on whole body (WB) BMC and BMD of the hip and lumbar spine (LS) of adolescent girls. METHODS: In a matched case-control study, girls (n = 5) who applied Ortho Evra for days 1-21 followed by days 22-28 free of medication for 13 cycles (about 12 months) were compared with 5 age- and ethnicity-matched control girls. Evaluations of calcium intake; bone-protective physical activity; bone densitometry (DXA, QDR 4500A, Hologic); bone formation markers serum osteocalcin (OC) and bone-specific alkaline phosphatase (BAP); bone resorption marker urinary N-telopeptide (uNTX); insulin growth factor-1 (IGF-1); and sex hormone binding globulin (SHBG) were carried out at initiation, 6 months, and 12 months. Changes from baseline were compared using mixed models, adjusting for follow-up comparisons using the Holm Test (sequential Bonferroni). RESULTS: There were no significant differences (SD) between groups at baseline in age, gynecologic age, WBBMC, hip BMD, and LSBMD. Girls on Ortho Evra did not change significantly in WBBMC (12-month mean increase 0.2% +/- 0.8%), whereas controls did (3.9% +/- 1.8%, P < or = .001, adjusted P = .002), with SD between the 2 groups (P = .007, adjusted P = .036). Adolescents on Ortho Evra did not change significantly in hip BMD (12-month mean increase 0.5% +/- 0.6%), whereas controls did (2.7% +/- 0.6%, P < or = .001, adjusted P = .004), with SD between the 2 groups (P = .024) prior to adjustment for multiple comparisons, but no SD after adjustment (P = .096). Similarly, although the increase in LSBMD within the control group after 12 months (mean increase 2.8% +/- 1.0%) was statistically significant (P = .009, adjusted P = .044), the change within the treatment group (12-month mean increase 0.8% +/- 0.8%) was not. However, percent LSBMD changes after 12 months did not significantly differ between the 2 groups before or after adjustment for multiple comparisons. Calcium intake and bone-protective physical activity did not significantly predict BMC and BMD changes of study participants. There was a significantly greater increase in SHBG levels in the treatment group after 6 months (P = .003, adjusted P = .013) and 12 months (P < or = .001, adjusted P < or = .001) than in controls. Changes in levels of OC, BAP, uNTX, and IGF-1 were not significantly different between the 2 groups. CONCLUSIONS: Ortho Evra use attenuates bone mass acquisition in young women who are still undergoing skeletal maturation. This attenuation may be attributed in part to increased SHBG levels, which reduce the concentrations of free estradiol and free testosterone that are available to interact with receptors on the bone. Clinical implications remain to be determined in studies with a larger number of adolescents.


Assuntos
Desenvolvimento Ósseo/efeitos dos fármacos , Anticoncepcionais Femininos/farmacologia , Etinilestradiol/farmacologia , Norgestrel/análogos & derivados , Adolescente , Desenvolvimento do Adolescente/efeitos dos fármacos , Fosfatase Alcalina/sangue , Densidade Óssea , Estudos de Casos e Controles , Criança , Colágeno Tipo I/urina , Combinação de Medicamentos , Feminino , Humanos , Fator de Crescimento Insulin-Like I/análise , Norgestrel/farmacologia , Osteocalcina/sangue , Peptídeos/urina , Projetos Piloto , Globulina de Ligação a Hormônio Sexual/análise , Globulina de Ligação a Hormônio Sexual/efeitos dos fármacos , Adulto Jovem
12.
Clin Pediatr (Phila) ; 49(1): 29-34, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19628760

RESUMO

A 12-hour fasting lipid profile was obtained from 88 otherwise healthy obese (BMI > or = 95%) adolescents (age 16 +/- 1 years, BMI 36 +/- 1 kg/m(2), 55 males, 33 females, 57% Hispanic, 23% African American, 19% Caucasian, 1% Asian American). About 56% of the obese adolescents exhibited lipid abnormalities based on cutoff points established by American Heart Association (AHA) guidelines, and about 57% exhibited lipid abnormalities based on percentile values established by the Lipid Research Clinic Pediatric Prevalence Study. Isolated low high-density lipoprotein-cholesterol (HDL-C) was the most common abnormality (43% based on AHA, 36% based on the Lipid Research Clinic Pediatric Prevalence Study) among the obese adolescents with lipid disorders. While there was no significant statistical difference (SSD) between genders in the levels of total cholesterol and low-density lipoprotein-cholesterol (LDL-C), triglyceride (TG) levels were significantly higher (P = .003) in males (120 +/- 11 mg/dL) than in females (81 +/- 7 mg/dL), and levels of HDL-C were significantly higher (P = .006) in females (42 +/- 2 mg/dL) than in males (35 +/- 1 mg/dL). There was no SSD between races in total cholesterol and LDL-C levels. TG levels were significantly lower in African-American participants (81 +/- 9 mg/ dL) compared with levels in Caucasian participants (117 +/- 15 mg/dL, P

Assuntos
HDL-Colesterol/sangue , Dislipidemias/sangue , Obesidade/sangue , Adolescente , Distribuição de Qui-Quadrado , Criança , Dislipidemias/etnologia , Feminino , Humanos , Masculino , Obesidade/etnologia , Estudos Retrospectivos , Adulto Jovem
13.
Expert Opin Pharmacother ; 9(15): 2661-72, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18803452

RESUMO

BACKGROUND: Dysmenorrhea is the most common gynecologic complaint among adolescent and young adult females. Dysmenorrhea is usually primary and is associated with normal ovulatory cycles and with no pelvic pathology. In approximately 10% of females with severe dysmenorrhea symptoms, pelvic abnormalities such as endometriosis or uterine anomalies may be found. OBJECTIVE: To review the current knowledge regarding the pathophysiology of dysmenorrhea, as well as review pharmacological treatments and strategies for management of dysmenorrhea in adolescent and young adult females. METHODS: Review of original articles on dysmenorrhea that have been published in the medical literature. RESULTS/CONCLUSIONS: Potent prostaglandins and potent leukotrienes play an important role in generating primary dysmenorrhea symptoms. Non-steroidal anti-inflammatory drugs (NSAIDs) are the most common pharmacologic treatment for dysmenorrhea. A loading dose of NSAIDs (typically twice the regular dose) should be used as initial treatment for dysmenorrhea, followed by a regular dose until symptoms abate. Adolescents and young adults with symptoms that do not respond to treatment with NSAIDs for three menstrual periods should be offered hormonal treatment such as combined estrogen/progestin oral contraceptive pills (OCPs) for three menstrual cycles. If dysmenorrhea does not improve within 6 months of treatment with NSAID and OCPs, a laparoscopy is indicated to look for endometriosis. The goal of pharmacological treatment for endometriosis is to block its abnormal positive feedback loop. The abnormal loop consists of high local levels of estrogen in the lesions, which induce transcription of COX-2 and synthesis of prostaglandin E(2.) This results in further expression and activity of aromatase and a further increase in estrogen.


Assuntos
Dismenorreia/tratamento farmacológico , Dismenorreia/fisiopatologia , Dor Abdominal , Adolescente , Anti-Inflamatórios não Esteroides/uso terapêutico , Anticoncepcionais Orais Combinados/uso terapêutico , Anticoncepcionais Orais Hormonais/uso terapêutico , Dismenorreia/etiologia , Dismenorreia/cirurgia , Feminino , Humanos , Fatores de Risco , Adulto Jovem
14.
Ann N Y Acad Sci ; 1135: 185-95, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18574224

RESUMO

Dysmenorrhea is the most common gynecologic complaint among adolescent females. Dysmenorrhea in adolescents is usually primary, and is associated with normal ovulatory cycles and with no pelvic pathology. In approximately 10% of adolescents with severe dysmenorrheic symptoms, pelvic abnormalities such as endometriosis or uterine anomalies may be found. Potent prostaglandins and leukotrienes play an important role in generating the symptoms of dysmenorrhea. Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most common pharmacologic treatment for dysmenorrhea. A loading dose of NSAIDs (typically twice the regular dose) should be used as initial treatment for dysmenorrhea in adolescents, followed by a regular dose until symptoms abate. Adolescents with symptoms that do not respond to treatment with NSAIDs for three menstrual periods should be offered hormonal treatment such as combined estrogen/progestin oral contraceptive pills for three menstrual cycles. Adolescents with dysmenorrhea who do not respond to this treatment should be evaluated for secondary causes of dysmenorrhea. The adolescent care provider's role is to explain the pathophysiology of dysmenorrhea to every adolescent female, address any concern that the patient has about her menstrual period, and review effective treatment options for dysmenorrhea with the patient.


Assuntos
Dismenorreia/epidemiologia , Dismenorreia/etiologia , Ciclo Menstrual/fisiologia , Adolescente , Anti-Inflamatórios não Esteroides/uso terapêutico , Anticoncepcionais Orais Combinados/uso terapêutico , Anticoncepcionais Orais Hormonais/uso terapêutico , Dismenorreia/diagnóstico , Dismenorreia/fisiopatologia , Dismenorreia/terapia , Estrogênios/uso terapêutico , Feminino , Humanos , Prevalência , Congêneres da Progesterona/uso terapêutico , Fatores de Risco
15.
Contraception ; 77(4): 239-48, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18342646

RESUMO

BACKGROUND: This analysis was conducted to assess the baseline data and design methodology within an observational longitudinal comparison of use vs. nonuse of the injectable (intramuscular) contraceptive depot medroxyprogesterone acetate (DMPA-IM) and its effect on bone mass in adolescent women. STUDY DESIGN: A prospective, observational, open-label, unmatched-cohort, safety study in females aged 11-18 years. Participants either self-selected DMPA-IM (Depo-Provera) 150 mg to be administered every 12 weeks for up to 240 weeks with a 120-week post-treatment follow-up or were nonusers (users of nonhormonal contraception or sexually abstinent) who were to be followed up for up to 360 weeks. As each participant entered the study, bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry at the lumbar spine, hip and femoral neck regions, along with total body bone mineral content; serum and urine specimens were obtained for assay of bone metabolism markers and participants' histories of parity and tobacco and alcohol use were obtained. RESULTS: A total of 389 participants were enrolled: 169 elected to begin DMPA-IM; 26 chose nonhormonal methods and 194 were abstinent. The baseline characteristics indicated significant disparities between DMPA-IM users and nonusers: compared with the nonusers, DMPA-IM users had more advanced chronologic and gynecologic ages, were more likely to have smoked, been pregnant and included more blacks. These factors would likely influence bone accretion rates independent of DMPA-IM exposure. Comparison of participant BMDs with standard reference data revealed that the study cohorts did not match reference populations closely enough to make a direct between-cohort comparative analysis feasible. CONCLUSIONS: The baseline differences in cohort characteristics preclude a meaningful comparison of mean BMD changes over time between DMPA-IM users and nonusers cohorts, and comparisons of changes in Z-scores between cohorts were also not appropriate. Therefore, within-participant BMD decreases from baseline were established as safety thresholds, and the proportion of individuals crossing those thresholds on a persistent or progressive basis was identified as the revised primary end point.


Assuntos
Densidade Óssea/efeitos dos fármacos , Anticoncepcionais Femininos/farmacologia , Acetato de Medroxiprogesterona/farmacologia , Adolescente , Criança , Feminino , Humanos , Estudos Prospectivos
16.
Adolesc Med State Art Rev ; 19(3): 573-91, xi, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19227392

RESUMO

Adolescence is a critical period for determining peak bone mass. During this time, bone formation prevails over resorption, and approximately 40% of the total bone mass is accumulated. Several factors affect the accretion of bone mass during adolescence. Although genetic predisposition, age, race, and ethnicity cannot be modified, factors such as nutrition, physical activity, and lifestyle choices can be changed. Promoting a healthy lifestyle, regular weight-bearing physical activity, and a healthy diet with optimal calcium and vitamin D intake may prove to be the best way to achieve a maximal peak bone mass. This review discusses the known, the unknown, and the controversial regarding bone metabolism during adolescence.


Assuntos
Osso e Ossos/metabolismo , Adolescente , Fatores Etários , Consumo de Bebidas Alcoólicas , Biomarcadores , Índice de Massa Corporal , Doença Crônica , Suplementos Nutricionais , Feminino , Predisposição Genética para Doença , Número de Gestações , Humanos , Gravidez , Grupos Raciais , Fatores de Risco , Fatores Sexuais , Fumar
17.
J Adolesc Health ; 40(1): 44-53, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17185205

RESUMO

PURPOSE: During adolescence, bone formation prevails over resorption, resulting in accumulation of 40% of peak bone mass throughout this time period. Although multiple studies have explored bone mass accrual during the early stages of puberty, less is known about factors that may influence bone accrual during later years of adolescence. In the present cross-sectional study we examined relationships among bone mineral density (BMD) and demographic factors, behavioral variables, and bone metabolism markers in postmenarchal adolescent girls. METHODS: The population was comprised of 389 healthy postmenarchal adolescent girls aged 11-18 years, who were recruited into a prospective study of the effect of depot medroxyprogesterone acetate (DMPA) on bone health in adolescents. At the baseline visit, investigators collected demographic, reproductive health, and lifestyle data, and performed a complete physical examination. Body mass index (BMI) was calculated. Before study initiation, BMD at the lumbar spine, total hip, and femoral neck was measured by dual-energy X-ray absorptiometry (DXA), and markers of bone metabolism (serum bone-specific alkaline phosphatase [BAP], serum osteocalcin, and urinary N-telopeptide [uNTX]) were measured. The baseline data from this study were analyzed to evaluate possible correlates of BMD in postmenarchal adolescent girls. Potential associations between BMD values and other parameters were assessed by analysis of variance and Pearson's correlation coefficient. RESULTS: Participants enrolled in the study had a mean (+/- SD) chronological age of 14.9 +/-1.7 years (range 11-18), mean gynecologic age of 39.9 +/-23.0 months (range 1-120) postmenarche, and mean BMI of 23.5 +/-4.6 kg/m(2) (range 16.0-42.2). Racial/ethnic distribution was 46% African American, 35% Caucasian, and 19% other races; 9% had previously been pregnant. Positive correlations were observed between lumbar spine BMD and chronological age (r = .301, p < .0001), gynecologic age (r = .349, p < .0001), and BMI (r = .371, p < .0001). Total hip and femoral neck BMD values were significantly higher (p < .05 and p < .05, respectively) in African American participants compared with non-African American participants. Previous history of pregnancy was significantly associated with a lower BMD at the lumbar spine (p < .0001) and the total hip (p < .01) when compared with the BMD of adolescents who had never been pregnant. Cigarette smoking and alcohol use were not associated with significant differences in BMD. Negative correlations were observed between gynecologic age and the levels of BAP (r = -.564, p < .0001), osteocalcin (r = -.349, p < .0001), and uNTX (r = -.281, p < .0001), and between lumbar spine BMD and BAP (r = -.363, p < .0001), osteocalcin (r = -.129, p < .05), and uNTX (r = -.202, p < .001) levels. CONCLUSIONS: Our data demonstrate that chronological age, gynecologic age, race/ethnicity, BMI, and previous history of pregnancy are markedly associated with BMD in postmenarchal adolescent girls. Bone accretion in the postmenarchal years continues in the face of a slowdown in bone turnover during this time period.


Assuntos
Densidade Óssea , Osso e Ossos/metabolismo , Adolescente , Fatores Etários , Análise de Variância , Biomarcadores , Índice de Massa Corporal , Criança , Estudos Transversais , Feminino , Humanos , Estilo de Vida , História Reprodutiva , Fatores Socioeconômicos , Estados Unidos
18.
J Pediatr Adolesc Gynecol ; 19(6): 363-71, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17174824

RESUMO

Dysmenorrhea is the most common gynecologic complaint among adolescent and young adult females. Dysmenorrhea in adolescents and young adults is usually primary (functional), and is associated with normal ovulatory cycles and with no pelvic pathology. In approximately 10% of adolescents and young adults with severe dysmenorrhea symptoms, pelvic abnormalities such as endometriosis or uterine anomalies may be found. Potent prostaglandins and potent leukotrienes play an important role in generating dysmenorrhea symptoms. Nonsteroidal anti-inflammatory drugs (NSAID) are the most common pharmacologic treatment for dysmenorrhea. Adolescents and young adults with symptoms that do not respond to treatment with NSAIDs for 3 menstrual periods should be offered combined estrogen/progestin oral contraceptive pills for 3 menstrual cycles. Adolescents and young adults with dysmenorrhea who do not respond to this treatment should be evaluated for secondary causes of dysmenorrhea. The care provider's role is to explain about pathophysiology of dysmenorrhea to every adolescent and young adult female, address any concern that the patient has about her menstrual period, and review effective treatment options for dysmenorrhea with the patient.


Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Anticoncepcionais Orais Hormonais/uso terapêutico , Dismenorreia/tratamento farmacológico , Dismenorreia/etiologia , Adolescente , Dismenorreia/fisiopatologia , Feminino , Humanos
20.
J Pediatr Adolesc Gynecol ; 18(2): 85-90, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15897103

RESUMO

BACKGROUND: The new combined estrogen & progestin contraceptive patch Ortho Evra was approved by the FDA in December 2001. To date, there is a paucity of data regarding its use in the adolescent age group. We examined adolescents' experience with this new contraceptive method. METHODS: Using a questionnaire designed by the authors, care providers in a hospital based adolescent clinic interviewed and reviewed the charts of adolescent girls who had initiated Ortho Evra in 2002-2003. RESULTS: Twenty-eight adolescent girls (age 18 +/- 1 years, gyn age 6 +/- 1 years, onset of sexual intercourse at 14 +/- 1 years, body mass index (BMI) 27.6 +/- 1.2, 57% Hispanic, 21% Caucasian, 11% African American, 7% biracial, 4% Indian American) who had used Ortho Evra for 7 +/- 1 months were enrolled. Half (50%) were adolescent mothers, and 57% had a history of irregular menstrual periods. All (100%) girls reported regular menstrual periods while using Ortho Evra, with only 14% experiencing occasional breakthrough bleeding. Half reported a shorter duration and 36% reported a lighter flow of their periods. About a third (39%) reported a decrease and 11% reported an increase in dysmenorrhea symptoms. About a third (29%) of those with a history of recurrent headaches at initiation reported decrease in headaches, and about a third (33%) of those with acne at initiation reported decrease in facial acne while on Ortho Evra. There were no significant BMI changes during Ortho Evra use. Although condom use while on Ortho Evra was poor (only 15% reporting consistent condom use), there were no pregnancies reported. A majority (93%) reported that they remembered to apply the patches on time, and 40% stated that Ortho Evra was easier than previous contraceptive methods. Two thirds (68%) were very satisfied and 29% were somewhat satisfied with the method, and 93% stated that they would recommend the method to a friend/relative. The preferred application site was the buttock (40%) followed by the lower abdomen (32%). About a fifth (21%) experienced at least one episode of complete patch detachment and 32% reported partial peeling of the patch corners. About a third (32%) would prefer another patch color, and 25% would like a fourth week placebo patch. The most common side effects were mild temporary application site reactions (64%), some discomfort on patch removal (32%), nausea (18%), and breast tenderness (18%). Eleven girls (39%) discontinued Ortho Evra (three lost health insurance, three because of application site reactions, two found patch application schedule difficult to remember, two desired pregnancy, two because of nausea, one because of perceived weight gain). CONCLUSIONS: Ortho Evra provides excellent cycle control in adolescents. Most adolescents are satisfied with this method. Intensive efforts should be made to increase condom use by adolescents on Ortho Evra.


Assuntos
Anticoncepcionais Orais Combinados/administração & dosagem , Abdome , Acne Vulgar/prevenção & controle , Administração Cutânea , Adolescente , Atitude Frente a Saúde , Mama/efeitos dos fármacos , Nádegas , Preservativos , Anticoncepcionais Orais Combinados/efeitos adversos , Portadores de Fármacos , Combinação de Medicamentos , Dismenorreia/prevenção & controle , Etisterona/análogos & derivados , Feminino , Cefaleia/prevenção & controle , Humanos , Ciclo Menstrual/efeitos dos fármacos , Menstruação/efeitos dos fármacos , Náusea/induzido quimicamente , Norgestrel/análogos & derivados , Oximas , Pacientes Desistentes do Tratamento , Satisfação do Paciente
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