Endocrine Abstracts

Objective: Muslims worship by fasting from pre-dawn (suhoor) until sunset (iftar) for 30 days in the religious month of Ramadan. In addition to prolonged hunger, patients fasting with a diagnosis of hypothyroidism take their doses of levothyroxine outside of daytime fasting hours. This study compares thyroid functions of fasting hypothyroidism patients with the values before Ramadan.

Methods: One hundred patients aged 18–65 years were included in the study, who were followed with a diagnosis of hypothyroidism, who fasted during Ramadan, and who had no change of levothyroxine dose for at least for 6 months.

Results: The median serum thyroid-stimulating hormone (TSH) level of patients prior to fasting was 2.1 mIU/l (0.04–9.09), while median serum TSH after fasting was 2.8 mIU/l (0.01–21.21). Serum TSH values after Ramadan increased significantly compared to those prior to Ramadan (P<0.01). No significant difference was seen in serum sT4 levels. A statistical difference in TSH increase was not determined between patients taking their levothyroxine dose at iftar and patients taking it at suhoor. A positive correlation was found with sT4 levels and a negative correlation was found with serum TSH levels for daily drug dose and serum TSH levels after Ramadan.

Conclusion: Our study demonstrates a significant increase of serum TSH levels after Ramadan but no significant change of serum sT4 levels in hypothyroidism patients who are fasting. Therefore, we suggest the precaution of a small increase in levothyroxine dose before Ramadan for hypothyroidism patient who plan to fast.