» Articles » PMID: 34136323

Weight and Body Mass Index for Predicting Thyroxine Dose in Primary Hypothyroidism

Overview
Journal Cureus
Date 2021 Jun 17
PMID 34136323
Authors
Affiliations
Soon will be listed here.
Abstract

Background The treatment of primary hypothyroidism with thyroxine is weight-based or body mass index (BMI)-based. However, significant variation in the dose and the consequent delay in achieving euthyroid state is observed along the spectrum of patient body weights. Objectives To determine the weight and BMI-based dosing of thyroxine in primary hypothyroidism to achieve euthyroidism Material and methods It was a retrospective review of the patient records conducted in the department of endocrinology, Shifa International Hospital, Islamabad, from July 1, 2014, to June 30, 2019 (five-year period) Patients with clinical and biochemical hypothyroidism were enrolled and initiated on thyroxine replacement to achieve euthyroid status. A total of 504 patients were included in the study. Results The mean age was 44.5 ±13.6 standard deviation. Females were 83.5%. The mean dose of thyroxine to achieve euthyroid status was 107.7 ± 39.3 mean standard deviation mcg/day, i.e. 1.4 (0.5) mcg/kg/day. Euthyroid status was achieved in 264 (52.4%) of patients at three months. The mean TSH level after treatment was 2.09 (1.2) mU/L. The linear regression model showed that BMI and weight are independent predictors of the required thyroxine dose (R and Rsquare values are .274 and 0.075 for BMI and .319 and .102 for weight, respectively (P-value <.0001). There was no impact of age, gender, height, and duration of disease on achieving euthyroid at six months after treatment (P values: .85, .394, .827, and .105, respectively). Conclusion The optimum dose in primary hyperthyroidism can be determined with body weight and BMI-based calculations.

References
1.
Chen S, Zaborek N, Doubleday A, Schaefer S, Long K, Pitt S . Optimizing Levothyroxine Dose Adjustment After Thyroidectomy With a Decision Tree. J Surg Res. 2019; 244:102-106. PMC: 7041547. DOI: 10.1016/j.jss.2019.06.025. View

2.
Duntas L, Jonklaas J . Levothyroxine Dose Adjustment to Optimise Therapy Throughout a Patient's Lifetime. Adv Ther. 2019; 36(Suppl 2):30-46. PMC: 6822824. DOI: 10.1007/s12325-019-01078-2. View

3.
Jonklaas J, Tefera E, Shara N . Physician Choice of Hypothyroidism Therapy: Influence of Patient Characteristics. Thyroid. 2018; 28(11):1416-1424. PMC: 6247977. DOI: 10.1089/thy.2018.0325. View

4.
Tan N, Chew R, Koh Y, Subramanian R, Sankari U, Meyappan M . Primary hypothyroidism in the community: Lower daily dosages of levothyroxine replacement therapy for Asian patients. Medicine (Baltimore). 2017; 96(7):e6145. PMC: 5319534. DOI: 10.1097/MD.0000000000006145. View

5.
Midgley J, Toft A, Larisch R, Dietrich J, Hoermann R . Time for a reassessment of the treatment of hypothyroidism. BMC Endocr Disord. 2019; 19(1):37. PMC: 6471951. DOI: 10.1186/s12902-019-0365-4. View