Abstract
The effects of Ramadan fasting on thyroid function tests in healthy male subjects were investigated. Plasma thyroxine (T4), Triiodothyronine (T3), thyroid stimulating hormone (TSH) and free T4 levels were determined in 28 healthy male subjects before and at the end of the 30 day Ramadan fast. The effect of short term food deprivation between dawn and sunset was also investigated. There were no significant differences between the morning and evening (after 14 hour fast) values in the thyroid function tests; the respective values (means ± SD) for a.m. and p.m. Plasma T4, T3, free T4 and TSH being 7.1±1.34 μg% and 7.2±1.33 μg%; 1.1±0.17 ng% and 1.1±0.11; 1.1±0.15 ng/dL and 1.1±0.20 ng/dL; 1.9±0.81 mu/ml and 1.4±0.51 mu/ml respectively; P>0.1 for all comparisons. In addition, there was no significant change in the results of the thyroid function tests done before and at the end of Ramadan. The values respectively for plasma T4, T3, free T4 and TSH before and after Ramadan were 7.0±1.08 μg% and 7.1±1.34 μg%; 1.1±0.17 ng/ml and 1.1±17 ng/ml; 1.1±0.21 ng/dL and 1.1±0.15 ng/dL; 1.7±0.62 mu/ml and 1.4±0.81 mu/ml; P>0.1 for all comparisons. It is concluded that Ramadan fasting by healthy adult males did not alter the standard indices of thyroid function.