Space Physiology
Head: Prof. Dr. med. Jörn Rittweger

Field Studies to Examine the Effect of Nutrient Countermeasures on Bone Loss

Long term changes, occurring by the supplementation of macro- or macronutrient, can not be observed in our metabolic ward, because of psychological, financial and operability aspects. We therefore carry out field studies.

ANO-Study (Anorexia Nervosa and Osteoporosis)

In co-operation with the university hospital Aachen, department of child and adolescent psychiatry (Prof. Herpertz-Dahlmann) we started a study to measure the effect of a dietetic therapy on 20 young patients with anorexia nervosa. Patients with anorexia nervosa often suffer from osteoporosis. Interestingly, these patients have the same pattern in bone resorption and formation markers than astronauts have. In astronauts this is often associated with an insufficient nutrient supply. Recent studies have shown that reduced energy intake might decrease bone metabolism in astronauts. We therefore examined in a two-year study if a dietary treatment including an individually determined high caloric intake, calcium and vitamin D supplementation would improve bone metabolism in these patients. The first results show that the dietary treatment leads to an increase in bone formation activity associated with a constant bone resorption rate (Heer M. et al., Clin. Chem., 2002). How far this positive effect of the dietary therapy is applicable to astronauts in space remains to be proved. In 2003 the two-years study is finished and the examination of the control group will be continued.

KAR-Study (Bone Metabolism and Arginine)

In co-operation with the university hospital Cologne (Prof. E. Schönau, University children´s hospital) we are examining the effect of a six months daily oral supplementation with L-argininehydrochloride on bone metabolism of healthy postmenopausal women in an ambulant study.

Recent experimental evidence indicate a positive effect of the free radical Nitric oxide (NO) on bone metabolism. The NO-level of the human body can be elevated through application of pharmacological NO-donors. The first human trials conducted showed a positive effect of an NO-donor application on the metabolism of human bones. The question is if L-arginine, the natural precursor of NO-synthesis, will have the same bearing on bone metabolism as a NO-donor application.

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