A Prospective Study Comparing Two-Time Points of Thyroid Hormone Replacement during the Holy Month of Ramadan

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.

Levothyroxine Timing during Ramadan: A Randomized Clinical Trial

INTRODUCTION

Hypothyroidism requires lifelong thyroid hormone replacement with levothyroxine. For most hypothyroid patients fasting during Ramadan, compliance with the administration procedure is a challenge. This study aimed to determine the impact of different administration times of levothyroxine on thyroid-stimulating hormone (TSH) and free T4 (FT4) levels before and after the holy month of Ramadan. Materials and Methodology. Hypothyroid patients taking levothyroxine were randomized to 3 groups during Ramadan: group 1, 30 minutes before the iftar meal; group 2, 3-4 hours after the iftar meal, with no food taken for at least 1 hour after the meal; group 3, they were not given specific instructions for taking levothyroxine during Ramadan. Thyroid function tests were performed within 2 weeks before Ramadan and within 2 weeks after Ramadan. Pre- and post-Ramadan TSH and free T4 levels were compared. Mixed-effects analyzes were performed to identify factors associated with changes in TSH and FT4 levels.

RESULTS

Compliance was lower in patients taking levothyroxine 3-4 hours after iftar. In addition, the majority of patients who had not received a specific recommendation took levothyroxine 30 minutes before iftar. There was a statistically significant increase in TSH (P=0.006) and FT4 (P=0.044) levels after Ramadan. In multivariate analysis, the cause of hypothyroidism (Hashimoto's; postthyroidectomy; compared to postradioactive iodine) and levothyroxine dose significantly affected FT4 levels. In contrast, no variable was significantly associated with TSH level. The timing of levothyroxine intake during Ramadan did not significantly affect TSH or FT4 levels.

CONCLUSION

TSH and FT4 significantly increased after Ramadan. However, the timing of levothyroxine intake per se had no influence on TSH or free T4 levels. Therefore, hypothyroid patients might take levothyroxine either 30 minutes or 3-4 hours after iftar with no meal for 1 hour, depending on preference.

Optimal Timing of Thyroid Hormone Replacement During Ramadan Fasting: A Randomized Controlled Trial in Patients with Prior Total Thyroidectomy

Background: Fasting during Ramadan may be challenging for patients on levothyroxine (LT4), as the drug has a narrow therapeutic index and is administered on an empty stomach. The majority of Muslims who fast in Ramadan have two meals per day, iftar immediately after sunset and suhoor just before dawn. This study aimed at evaluating the impact of LT4 timing during Ramadan on thyrotropin (TSH) levels in patients who underwent total thyroidectomy to determine the best timing for intake and identify the predictors of TSH level changes. Methods: We conducted a parallel, double-blind, randomized controlled trial on Saudi patients diagnosed with hypothyroidism who underwent total thyroidectomy. Patients were required to have stable thyroid function for 6 months before the study period and fast ≥20 days of Ramadan. Participants were randomized to one of three times for LT4 administration: Group A, 30 minutes pre-iftar (n = 48); Group B, 3 hours post-iftar (n = 47); or Group C, 1 hour pre-suhoor (n = 47). The number of participants in the final analysis (excluding patients who dropped out) was as follows: Group A, (n = 31); Group B, (n = 34); and Group C, (n = 22). The changes in TSH and free thyroxine (fT4) levels two weeks before and after Ramadan were compared. Factors associated with a change in TSH levels were examined through multivariable analysis. Results: The TSH levels significantly increased in Group B (1.7 ± 1.8 mU/L vs. 3.1 ± 3.9 mU/L, p = 0.003) and Group C (2 ± 1.7 mU/L vs. 5.5 ± 10 mU/L, p = 0.011), but not Group A (1.8 ± 1.6 mU/L vs. 3.3 ± 4.2 mU/L, p = 0.158). The change in fT4 levels was comparable among the groups: Group A, 16.5 ± 2.7 mcg/dL vs. 15.9 ± 3.2 mcg/dL, p = 0.144; Group B, 15.8 ± 3.8 mcg/dL vs. 16.3 ± 3.6 mcg/dL, p = 0.620; and Group C, 17.5 ± 2.8 mcg/dL vs. 17.3 ± 3.9 mcg/dL, p = 0.770. In multivariable linear regression analysis, the following variables were significantly independently associated with TSH level change: age, weight gain, and the number of nonadherence days to LT4, where β = -0.2, p = 0.026; β = + 0.2, p = 0.026; and β = + 0.5, p < 0.0001, respectively. Conclusions: Fasting patients who took LT4 pre-iftar did not experience significant changes in TSH, whereas those who took LT4 post-iftar or pre-suhoor did. The TSH changes during Ramadan may be associated with age (inverse association), weight gain, and the number of non-adherence to LT4 days. Trial Registration: SCTR Application no. 21122002.

Ramadan Fasting and Changes in Thyroid Function in Hypothyroidism: Identifying Patients at Risk

Background: Ramadan fasting (RF) is associated with major changes in meal times. This can affect thyroxine absorption and thyroid function (TF) in patients with hypothyroidism. We aimed to examine the short- and long-term impact of RF on TF in patients with primary hypothyroidism on levothyroxine. Methods: TF tests in patients with primary hypothyroidism attending an endocrine center in the United Arab Emirates were retrospectively analyzed. The impact of RF on TF, namely serum thyrotropin (TSH) TSH, free thyroxine (fT4) and free triiodothyronine (fT3), was investigated in 481 patients within 3 months before Ramadan (BR), 1-2 weeks (PR1), and 3-6 months (PR2) post-Ramadan. Controlled TF was defined as TSH between 0.45 and 4.5 μIU/mL. Inadequate control was defined as TSH >4.5 μIU/mL. Loss of control was defined as having controlled TF at BR and inadequate control at PR1. Multivariable regression analyses were used to assess the association of baseline TSH, baseline levothyroxine dose, and medication use with loss of thyroid control in Ramadan. Results: TSH increased significantly from a median of 2.0 (0.8-3.7) μIU/mL at BR to 2.9 (1.4-5.6) μIU/mL at PR1 (p < 0.001). This was accompanied by a fall in fT4 and fT3 at PR1 (p < 0.001). 25.5% of patients with previously controlled TF at BR had deterioration in TF at PR1. Sixty-one percent of patients with previously uncontrolled TF at BR remained uncontrolled at PR1. Baseline TSH was significantly associated with loss of thyroid control in Ramadan with an odds ratio (95% confidence interval) of 1.5 (1.17-1.92) (p < 0.001), whereas other variables, including medications known to affect levothyroxine absorption were not associated with loss of control. TSH, fT4, and fT3 levels returned to normal at PR2. Conclusions: RF can negatively affect TF of patients on levothyroxine replacement. Although this effect is modest and transitory in most patients, a significant minority exhibit more pronounced, and clinically relevant changes. The latter includes those with higher TSH BR, and a smaller group whose thyroid disease appears to be particularly affected by the mealtime and lifestyle changes of Ramadan.

Optimal Thyroid Hormone Replacement

Hypothyroidism is a common endocrinopathy, and levothyroxine is frequently prescribed. Despite the basic tenets of initiating and adjusting levothyroxine being agreed on, there are many nuances and complexities to consistently maintaining euthyroidism. Understanding the impact of patient weight and residual thyroid function on initial levothyroxine dosage and consideration of age, comorbidities, thyrotropin goal, life stage, and quality of life as levothyroxine is adjusted can be challenging and continually evolving. Because levothyroxine is a lifelong medication, it is important to avoid risks from periods of overtreatment or undertreatment. For the subset of patients not restored to baseline health with levothyroxine, causes arising from all aspects of the patient's life (coexistent medical conditions, stressors, lifestyle, psychosocial factors) should be broadly considered. If such factors do not appear to be contributing, and biochemical euthyroidism has been successfully maintained, there may be benefit to a trial of combination therapy with levothyroxine and liothyronine. This is not supported by the majority of randomized clinical trials, but may be supported by other studies providing lower-quality evidence and by animal studies. Given this discrepancy, it is important that any trial of combination therapy be continued only as long as a patient benefit is being enjoyed. Monitoring for adverse effects, particularly in older or frail individuals, is necessary and combination therapy should not be used during pregnancy. A sustained-release liothyronine preparation has completed phase 1 testing and may soon be available for better designed and powered studies assessing whether combination therapy provides superior therapy for hypothyroidism.

John TJ, Santarina SA, Makia F, AlTakruri M, Kaskas A, Ahmed Y. Levothyroxine Administration during Ramadan: A Prospective Randomized Controlled Trial

BACKGROUND AND AIM

We have previously shown in a retrospective analysis that the plasma thyroid-stimulating hormone (TSH) rises significantly post-Ramadan in levothyroxine-treated hypothyroid patients, possibly as a result of lifestyle alterations and time restrictions during the nonfasting period from dusk until dawn. The aim of this study is to determine the best time to instruct patients to take levothyroxine during Ramadan so as to minimize changes in thyroid function tests during this period.

METHODS

In a randomized prospective design, hypothyroid patients taking levothyroxine were randomized to receive instructions to take levothyroxine at one of the following 3 times during Ramadan: (group 1) at dusk 30-min before Iftar meal, (group 2) 3 or more hours after Iftar meal, or (group 3) at dawn 30-min before Suhur meal. Thyroid function tests were performed within 3 months before Ramadan and within 6 weeks post-Ramadan. Data from patients with at least 1 blood test before or after Ramadan were analyzed using mixed-effects regression models.

RESULTS

Plasma TSH levels were available at one or more time points for 148 patients, group 1 (n = 50), group 2 (n = 46), and group 3 (n = 52). A statistically significant within-patient increase in plasma TSH was seen in patients at the 25th percentile pre-Ramadan in groups 2 and 3 (p values <0.001), but not in group 1. A statistically significant within-patient decrease in plasma TSH was found in patients at the 75th percentile in group 1 only. For patients at the 50th percentile pre-Ramadan, no statically significant within-patient changes were found, though descriptively, increases in plasma TSH were observed for groups 2 and 3, while a decrease was observed in group 1.

CONCLUSIONS

Our data suggest that instructing patients to take levothyroxine at the time of breaking the fast 30 min before the Iftar meal minimizes unfavorable changes in plasma TSH post-Ramadan. In contrast, instructing patients to take levothyroxine 3 h post-Iftar or 30 min before Suhur led to a greater rise in post-Ramadan TSH.

Preference, Adherence, and Maintenance of Euthyroidism Using 3 Different Regimens of Levothyroxine Intake during the Fasting Month of Ramadan

<b><i>Introduction:</i></b> Millions of Muslim hypothyroid patients fast during Ramadan. Limited data are available on the effect of fasting during Ramadan and different levothyroxine (L-T4) timings on thyroid status. The present study aimed to report preference, adherence, and maintenance of euthyroidism using 3 different regimens of L-T4 intake during Ramadan. <b><i>Methods:</i></b> This is a prospective study including Muslim hypothyroid patients fasting during Ramadan between 2018 and 2019. Patients freely chose between 3 regimens, regimen 1: to take L-T4 at sunset and postpone food and beverages for 60 min; regimen 2: to have iftar (first meal) at sunset, stop food and beverages for 3–4 h, have L-T4, and wait for 60 min before suhor (last meal); regimen 3: have suhor at midnight, stop food and beverages for 3–4 h, and have L-T4 before next fast. Thyroid status was assessed before and within 6 weeks after Ramadan. <b><i>Results:</i></b> 393 patients were included. The first 2 regimens or a combination of both was the most preferred by patients 40.5, 36.7, and 17%, respectively. 323/393 patients were adherent to L-T4 regimens (82.2%). 273/393 patients were euthyroid after Ramadan (69.5%). TSH pre- and post-Ramadan were 4.35 ± 12.30 mIU/L and 2.73 ± 3.37 mIU/L, respectively, with no statistically significant change (<i>p</i> = 0.225). Adherence was predicted post-Ramadan euthyroidism (odds ratio [OR] 2.8 in univariate and OR 2.96 in multivariate models). <b><i>Conclusions:</i></b> The first and second regimens or a combination of both was preferred by most patients. High rates of adherence and post-Ramadan euthyroidism were observed. Adherence to the preferred regimen is the main determinant of post-Ramadan euthyroidism.

Impact of Lifestyle Changes During Ramadan on Thyroid Function Tests in Hypothyroid Patients Taking Levothyroxine

OBJECTIVE

The holy month of Ramadan poses a challenge for levothyroxine-treated patients due to altered eating habits and time restrictions. The aim of this study was to examine the impact of lifestyle changes during Ramadan on thyroid function tests in hypothyroid patients taking levothyroxine in the United Arab Emirates.

METHODS

Retrospective design whereby levothyroxine-treated hypothyroid patients who had thyroid function tests within 3 months pre-Ramadan and within 2 months post-Ramadan were included. We looked at adherence to levothyroxine, eating pattern, and levothyroxine administration in relation to meal times during Ramadan. Pre- and post-Ramadan thyroid function tests and the potential impact of independent variables using a random-intercept mixed effects linear model were examined.

RESULTS

A total of 112 patients (89 females) were recruited in the study, with a mean age ± standard error (SE) of 44.70±1.36 years (range, 19.0 to 79.0 years). The mean thyroid-stimulating hormone (TSH) within 3 months before Ramadan was 1.809±0.094 mIU/L (median, 41.5 days; interquartile range &lsqb;IQR], 25.0 to 73.0 days), while the mean TSH within 2 months post-Ramadan was higher at 3.072±0.312 mIU/L (median, 27.5 days; IQR, 14.0 to 42.0 days). Post-Ramadan, 36 out of 112 patients had a plasma TSH outside of the normal reference range. The independent variable outcomes model showed that older patients and males were more likely to have an increased plasma TSH post-Ramadan. There was no relationship between the time of levothyroxine administration and change in TSH level.

CONCLUSION

Levothyroxine-treated hypothyroid patients showed a significant increase in plasma TSH post-Ramadan, amounting to 2.525 standard deviations, with older patients and males more likely to be affected.

ABBREVIATIONS

IQR = interquartile range; T4 = thyroxine; TSH = thyroid-stimulating hormone.