Gender Differences in Lipid Metabolism Responses to Long-Term Bed-Rest
- Paper number
IAC-06-A1.2.08
- Author
Mrs. Audrey Bergouignan, CNRS, France
- Coauthor
Mrs. Sylvie Normand, France
- Coauthor
Dr. Dale Schoeller, University of Wisconsin, United States
- Coauthor
Dr. Claude Gharib, France
- Coauthor
Dr. Guillemette Gauquelin-Koch, Centre National d'Etudes Spatiales (CNES), France
- Coauthor
Dr. Stéphane Blanc, CNRS, France
- Year
2006
- Abstract
A growing body of data suggests a direct relationship between nutrition and the deleterious effects of space on the human body that specifically involves the regulation of energy and substrates balances. Simulated microgravity induces a development of insulin-resistance associated to an hyperlipemia and a shift in substrate use. During a 7-day bed-rest we highlighted gender differences in such adaptation. Insulin resistance occurred at the muscle level in men, but at both the muscle and liver levels in women, and a shift toward glucose oxidation in men and a net lipogenesis in women were also noted. Although lipid balance determines energy balance and thus weight maintenance, few studies have focused on lipid oxidation during long-term bed rest. We investigated dietary fat trafficking during a three months of bed-rest in men (n=8) and observed a decrease in fat oxidation in both fasting and post-prandial states. Unexpectedly, whereas the oxidation of mono-unsaturated fatty acid remained unchanged, the oxidation of saturated fatty acid decreased significantly by 11%. A similar study was just completed in women (n=8) during a 2-month bed-rest (WISE 2005) and the results, under analysis, will be presented as compared to men. Taken together these two long term studies will provide a better understanding of the gender differences in response to the microgravity environment that is critical for the development of efficient countermeasures given the increasing number of women astronauts and the foreseen long-term missions to the Moon and Mars.
- Abstract document