Starting Hormone Therapy Research Articles

Results of bone densitometry affect women's decisions about taking measures to prevent fractures.

To describe how the results of bone densitometry affect women's decisions about measures to prevent fractures and to determine whether labeling women as having below-normal bone density has adverse effects. Mail survey of a random sample of women. Four community hospitals in the San Francisco Bay area. A total of 261 women (response rate, 81.3%) who had undergone bone densitometry. Bone densitometry and self-report of changes in attitude and behaviors. Fifty-three percent of the women reported that their first bone density measurements were below normal, and 44% said that they were diagnosed as having osteoporosis on the basis of their test results. Women who reported that their bone density measurements were below normal were much more likely than women with normal results to begin some type of measure to prevent fractures (94% compared with 56%; P less than 0.01), to start hormone therapy (38% compared with 8%; P less than 0.01), and to take precautions to avoid falling (50% compared with 9%; P less than 0.01). Women reporting low bone density, however, also became more fearful of falling (38% compared with 2%; P less than 0.01) and limited their activities to avoid falling (24% compared with 2%; P less than 0.01). The results of bone densitometry substantially influence women's decisions about beginning estrogen replacement therapy and other preventive measures for osteoporotic fractures. The potential effects of labeling a woman as having below-normal bone density need to be considered before densitometry is widely used for unselective screening of women.

The influence of thyroid hormone on rat colonic temperature during exercise.

Five male thyroidectomized rats were trained in motor-driven wheels until they were capable of running continuously for 1 h at 26.8 m/min. After the training period, colonic temperature were measured with a thermistor probe at rest, during pre-exercise activity, and during running at 13.4, 26.8, and 37.5 m/min. The colonic temperatures of the thyroidectomized rats were lower for all experimental conditions than those of normal rats. The animals were then given daily injections of 2 μg/100g body weight of triiodothyronine (T3) for the remainder of the experiment. One week after the start of hormone therapy, colonic temperatures were again determined under the conditions described above. T3 produced a rise in resting temperature to a level approximately that of normal rats. The difference between resting temperature and final temperature when the rats were running at 37.5 m/min was almost identical before and after hormone therapy. Thus, it appears that thyroid hormone is not essential for the increase in body temperature that accompanies exercise.