31.   Both elderly people and astronauts experience muscle loss, decreased bone density, sleep disturbances, hormone imbalances, weakened immune defenses and problems with balance and orientation.

32.   A group of women receiving hormone treatments had similar increases in bone density, while those receiving a placebo showed bone loss during the same period.

33.   After only a few days of weightlessness, astronauts begin losing bone density, she said.

34.   Build bone density.

35.   But resistance exercises also are important, since they build bone density.

36.   But the drug, made by Eli Lilly and Co., did not appear to increase bone density or lower cholesterol as much as traditional estrogen replacement therapy.

37.   Calcium is critical for bone growth and bone density, and the window for fostering both is limited.

38.   Calcitonin inhibits bone loss and can increase bone density when there are high levels of calcium in the blood.

39.   Clinical studies found that the spray, marketed under the name Miacalcin, increased spinal bone mineral density in women more than five years after menopause.

40.   Civitelli said that while either approach should protect women from bone loss, hormone replacement might be more likely to help women restore bone density already lost.