KUMJ | VOL. 11 | NO. 1 | ISSUE 41 | JAN-MAR, 2013
Thyroid Hormone levels in Highlanders- A Comparison Between Residents of Two Altitudes in Nepal
Nepal O, Pokhrel BR, Khanal K, Gyawali P, Malik SL, Koju R, Kapoor BK
Abstract: The endocrine changes related to altitude adaptation in human have attracted
physiologists around the globe for long. A number of high altitude studies to detect
the physiological changes have been performed now and then. But, the study
to see the hormonal changes to compare populations residing at different high
altitudes is a scarce. Hence, we have performed a study in native populations of
different high altitude comparing changes in thyroid hormones in western Nepal.
The Jharkot population included in this study is at altitude of 3760m and Jomsom
population at 2800m height from sea bed.
Objective
The study is to compare changes in thyroid hormones at two different high altitude
natives.
Methods
To compare thyroid status between high altitude natives at two different altitudes
a cross sectional study is performed by random sampling method. The blood
sample was collected in a vacutainer from fifty eight individuals after obtaining the
informed consent of participants. The blood collected from antecubital vein was
centrifuged in an hour and the serum obtained was used for biochemical analysis of
free triiodothyronine, free thyroxine and thyroid stimulating hormone.
Results
Mean free thyroxine (fT4) of Jharkot population is significantly larger (p = 0.001)
than Jomsom population. Mean thyroid stimulating hormone (TSH) with p =
0.597, does not indicate the difference between this two population. There is no
significant difference between mean free triiodothyronine (fT3) of Jharkot and
Jomsom population (p = 0.345).
Conclusion
The rise in free thyroid hormone at high altitude is not dependent on the thyroid
stimulating hormone released from anterior pituitary. The rise in free thyroxine
is found at higher altitude and no difference in fT3 level is detected in population
studied at high altitudes.
Keyword : Free triiodothyronine, free thyroxine, TSH, high altitude, t-test
