High school and college athletes are enrolling in strenuous fitness programs yet the long-term effect of such intense physical activity is not known. Exercise is very effective at inducing fat-loss which will be reflected by decreasing levels of leptin, a hormone that is produced by fat tissue. The total amount of body fat can affect the menstrual cycle in girls and very young women. This study is a research project that will determine leptin levels in girls and very young women in various states of physical fitness. The many benefits of exercise could be out-weighed by it's negative effect on a young women's menstrual cycle. The reduction of total body fat may be responsible for this effect of exercise even if there is no significant decrease in body weight. It is important to better understand how exercise affects women order to devise better ways to monitor the intensity of training. We plan to study a total of 80 adolescent girls of normal weight between 16 years and 20 years. There will be forty sedentary girls with normal cycles, 20 athletes with normal cycles and 20 athletes with menstrual irregularities. Twenty sedentary girls will be studied before and after four months of intensive training aiming at improving fitness while preserving a normal weight. Measurements of leptin, a hormone produced by fat tissue, may help in monitoring the minimal amount of body fat that is necessary for a normal menstrual cycle. Such information could help in designing effective and safe athletic programs for young women aiming at preserving the menstrual cycle and their ability to bear children.

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University of Michigan Ann Arbor
Ann Arbor
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Robarge, Jason D; Desta, Zereunesay; Nguyen, Anne T et al. (2017) Effects of exemestane and letrozole therapy on plasma concentrations of estrogens in a randomized trial of postmenopausal women with breast cancer. Breast Cancer Res Treat 161:453-461
Crane, Natania A; Jenkins, Lisanne M; Bhaumik, Runa et al. (2017) Multidimensional prediction of treatment response to antidepressants with cognitive control and functional MRI. Brain 140:472-486
Hertz, Daniel L; Speth, Kelly A; Kidwell, Kelley M et al. (2017) Variable aromatase inhibitor plasma concentrations do not correlate with circulating estrogen concentrations in post-menopausal breast cancer patients. Breast Cancer Res Treat 165:659-668
Hertz, D L; Kidwell, K M; Seewald, N J et al. (2017) Polymorphisms in drug-metabolizing enzymes and steady-state exemestane concentration in postmenopausal patients with breast cancer. Pharmacogenomics J 17:521-527
Kadakia, Kunal C; Kidwell, Kelley M; Seewald, Nicholas J et al. (2017) Prospective assessment of patient-reported outcomes and estradiol and drug concentrations in patients experiencing toxicity from adjuvant aromatase inhibitors. Breast Cancer Res Treat 164:411-419
Spengler, Erin K; Kleiner, David E; Fontana, Robert J (2017) Vemurafenib-induced granulomatous hepatitis. Hepatology 65:745-748
Heidemann, Lauren; Law, James; Fontana, Robert J (2017) A Text Searching Tool to Identify Patients with Idiosyncratic Drug-Induced Liver Injury. Dig Dis Sci 62:615-625
Law, Ian H; Alam, Osman; Bove, Edward L et al. (2016) Follow-Up of a Prospective Surgical Strategy to Prevent Intra-Atrial Reentrant Tachycardia After the Fontan Operation. Circ Arrhythm Electrophysiol 9:
Schrepf, Andrew; Harper, Daniel E; Harte, Steven E et al. (2016) Endogenous opioidergic dysregulation of pain in fibromyalgia: a PET and fMRI study. Pain 157:2217-2225
As-Sanie, Sawsan; Kim, Jieun; Schmidt-Wilcke, Tobias et al. (2016) Functional Connectivity is Associated With Altered Brain Chemistry in Women With Endometriosis-Associated Chronic Pelvic Pain. J Pain 17:1-13

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