Der Einfluss von Phytoöstrogenen, mehrfach ungesättigten Fettsäuren, Vitamin D und K auf den Knochenstoffwechsel und die Mikroarchitektur des Knochens

Osteoporosis has a major impact on health care costs in the
European Union. Not only for this reason effective therapy and
early prophylaxis are necessary. Hormone replacement therapy was
the treatment of choice until recently, but more and more risks
have been proven. Thus research on alternatives is of current
interest. Phytoestrogens, polyunsaturated fatty acids, as well as
vitamins D and K were found to have a positive impact on bone in
vitro and partially in vivo. In the present study effects of a
combination of genistein, polyunsaturated fatty acids and vitamin D
and K on bone metabolism and microarchitecture of bone in intact
and overiohysterectomized dogs were investigated. In a feeding
study twelve female beagle dogs were randomized into a study group
and a control group. After five months all dogs were
ovariohysterectomized and fed for another four months with control
food or food with the additional substances. Blood and urine
samples were taken every two or four weeks to analyse bone specific
alkaline phosphatase in serum for bone formation and
collagen-crosslinks pyridinoline and deoxypyridinoline in urine for
bone resorption. Bone biopsies were obtained from the ilium at
ovariohysterectomy and at the end of the study to do
microcomputertomographic and biochemical analyses. The combination
of substances was able to cause a prophylactic increase of bone
mineral content. After ovariohysterectomy bone turnover was
increased significantly (high turnover) and this rise could be
normalized. Microstructure was altered only little by
ovariohysterectomy, but a significant decrease in trabecular number
could be prevented by the combined substances. The results of this
study show, that a combination of genistein, polyunsaturated fatty
acids and vitamin D and K can have a protective effect on bone in
the intact as well as in the ovariohysterectomized beagle. This
combination could be a possible alternative to hormone replacement
therapy in postmenopausal osteoporosis.