Abstract
There is an increased frequency of dysthyroidism in elderly people. We investigated whether there are differences among healthy young-middle-aged and elderly people in the 24-hour secretory profiles of TRH, TSH and free thyroxine. The study was carried out on fifteen healthy young-middle-aged subjects (range 36-55 years, mean age±s.e. 44.1±1.7) and fifteen healthy elderly subjects (range 67-79 years, mean age±s.e. 68.5±1.2). TRH, TSH and free thyroxine serum levels were measured in blood samples collected every four hours for 24 hours. The area under the curve (AUC), the mean of 06:00h-10:00h-14:00h and the mean of 18:00h-22:00h-02:00h hormone serum levels and the presence of circadian rhythmicity were evaluated. A normal circadian rhythmicity was recognizable for TRH and TSH in young-middle-aged subjects and for TSH in elderly subjects. Elderly subjects presented lower TSH levels, whereas there was no statistically significant difference in TRH and free thyroxine serum levels between young-middle-aged and elderly subjects. Aging is associated with an altered TSH secretion.
| Original language | English |
|---|---|
| Pages (from-to) | 433-439 |
| Number of pages | 7 |
| Journal | Journal of Biological Regulators and Homeostatic Agents |
| Volume | 24 |
| Issue number | 4 |
| Publication status | Published - Oct 2010 |
Keywords
- Aging
- Circadian rhythm
- Hypothalamus-hypophysis-thyroid axis
ASJC Scopus subject areas
- Oncology
- Endocrinology, Diabetes and Metabolism
- Physiology (medical)
- Immunology and Allergy
- Immunology
- Endocrinology
- Physiology
- Cancer Research