Twice or Thrice Weekly versus Daily Thyroxine in Hypothyroid Fasting Ramadan: A Pilot Study

Effect of Ramadan fasting on thyroid functions in hypothyroid patients taking levothyroxine: a systematic review and meta-analysis

BACKGROUND

The major changes in the timing of meals during Ramadan may be challenging for hypothyroid patients on levothyroxine. We aimed to study the effect of Ramadan fasting on thyroid functions in hypothyroid patients taking levothyroxine.

METHODS

We did a comprehensive search of 8 databases for Randomized controlled studies (RCTs) and observational studies investigating the effect of Ramadan fasting on thyroid functions in hypothyroid individuals taking levothyroxine. Relevant data was extracted and analyzed. Mean difference (MD) and standard deviation (SD) were used to evaluate the continuous data. Risk ratios (RR) with a 95% confidence interval were used for outcomes constituting dichotomous data. National Institutes of Health (NIH) tools were used to assess the risk of bias.

RESULTS

Fourteen studies met our inclusion criteria, 3 RCTs, and 11 observational studies, all designed as pre-post studies. Ramadan fasting was associated with a statistically significant increase in TSH in patients who were euthyroid before Ramadan (MD = -0.76 [95% CI; -1.27, -0.25]). However, free thyroxine (FT4) was found to be stable (MD = 0.01, [95% CI; -0.03, 0.06]). All timing points were associated with a significant increase in TSH levels after Ramadan, pre-iftar (MD = -0.69 [95% CI; -1.03, -0.36]), post-iftar (MD = -0.76 [95% CI; -1.12, -0.39]), and pre-suhoor (MD = -1.19 [95% CI; -2.18, -0.19]).

CONCLUSION

TSH increases significantly after Ramadan. No timing point has superiority in maintaining thyroid control. However, choosing the timing should be individualized according to the patient's preference to guarantee the most possible compliance.

Twice or thrice weekly levothyroxine provides similar rates of adherence and post-Ramadan euthyroidism compared to daily levothyroxine during Ramadan fasting

BACKGROUND

Having to take levothyroxine (L-T4) on a daily basis, on an empty stomach is burdensome and may impair adherence, especially during Ramadan fasting. A long half-life and autoregulation of thyroid hormone levels allows for twice or thrice weekly administration of L-T4. This study aims to establish twice or thrice weekly L-T4 dosing as a convenient and effective practice during Ramadan fasting.

METHODS

The study included 2 groups; twice or thrice weekly (TTW) group included patients assigned to take L-T4 twice or thrice a week, and standard daily dosing (SDT) group included patients assigned to take L-T4 daily. Patients freely chose between three L-T4 regimens: before Iftar, before Suhor, or before the next fast. Thyroid status was assessed before and within 6 weeks after Ramadan. Only euthyroid patients were included.

RESULTS

TTW group included 57 patients, while SDT group included 91 patients. Pre-Ramadan TSH in TTW group (1.80 ± 0.88 µIU/L) was higher compared to SDT group (1.39 ± 0.72 µIU/L) [P = 0.003]. Similar adherence rates were observed in both groups, 96.5% in TTW group versus 89% in SDT group, [P = 0.13]. similar rates of post-Ramadan euthyroidism were also found in both groups, 91.2% in TTW group versus 94.5% in SDT group, [P = 0.509]. TTW group preferred regimen 1 (64.9%) significantly more than SDT group (35.2%) [P = 0.001].

CONCLUSION

Twice or thrice weekly levothyroxine results in similarly high rates of adherence (96.5%) and post-Ramadan euthyroidism (91.2%) compared to daily levothyroxine during Ramadan fasting.