Journal of Endocrinology and Metabolism, ISSN 1923-2861 print, 1923-287X online, Open Access
Article copyright, the authors; Journal compilation copyright, J Endocrinol Metab and Elmer Press Inc
Journal website http://www.jofem.org

Original Article

Volume 3, Number 1-2, April 2013, pages 1-6


Comparison Among the Daily Levothyroxine Doses According to the Etiology of Hypothyroidism

Tables

Table 1. Baseline Characteristics of Eligible Population According to Etiology of Hypothyroidism
 
Primary HypothyroidismCentral HypothyroidismPost-I131Post thyroidectomy (benign causes)Post thyroidectomy (malign causes)P value ‡
(‡) P value for comparison between groups.
Women n (%)321 (89.9)9 (56.3)18 (90.0)88 (95.7)58 (93.5)0.001
Age (Mean, years)51.749.750.454.653.40.527
BMI (Mean, kg/m2)26.827.528.426.626.20.496

 

Table 2. Mean Dose of Levothyroxine (µg) According to the Hypothyroidism Etiology
 
CH1 (n = 16)PH2 (n = 357)Post-I131(n = 20)Thyroidectomy (benign) (n = 92)Thyroidectomy (neoplasia) (n = 62)P value*
1CH: central hypothyroidism. 2PH: primary hypothyroidism. Dose/day: µg/day. Dose/weight/day: µg/kg/day. SD: standard deviation. (*) P value for comparison among the groups. Bonferroni’s post-hoc analysis: Hypothyroidism for malignant causes vs all other: P < 0.001; CH vs PH: P = 0.008; CH vs Post-I131: P = 0.001; CH vs post thyroidectomy: P < 0.001; PH vs Post I131: P = 0.319; PH vs thyroidectomy for benign causes: P < 0.001; Post I131vs thyroidectomy for benign causes: P = 1.0.
Dose/day53.9481.3797.42102.8138.5< 0.0001
SD28.0729.8428.3236.9635.25-
Dose/weight/day0.811.241.331.542.16< 0.0001
SD0.480.530.550.590.58-

 

Table 3. Mean Dose of Levothyroxine (µg) According to Age (Years)
 
Years≤ 20 (n = 23)21 - 30(n = 36)31 - 40(n = 53)41 - 50 (n = 119)51 – 60 (n = 148)61 - 70 (n = 101)> 70 (n = 62)P value
Dose/day: µg/day. Dose/weight/day: µg/kg/day. SD: standard deviation.
Dose/day70.1798.299097.8292.4584.6191.570.02
SD31.7047.4237.8735.8236.4032.991.06-
Dose/weight/day1.661.491.41.411.411.271.370.24
SD1.0050.760.660.600.580.510.32-

 

Table 4. Linear Regression for Final Required Levothyroxine Doses (Dependent Variable).
 
Variableβ CoefficientP Value(*)
(*) a variable was considered independently significant only when the p value was below the threshold for Bonferroni’s correction (in this case P value < 0.01).
BMI-0.1120.165
Weight0.2290.004
Age-0.0240.550
Gender0.1110.006
Etiology0.492< 0.001