J Endocrinol Metab

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 6, December 2013, pages 132-137

An Analysis for Aggravation of Thyroid Function After Discontinuing Potassium Iodine in Graves’ Patients Treated With Methimazole and Potassium Iodine

**Table 1.** Profile of Subjects (Mean ± SD)
Male:female	13:60
Age	14-67 (median 37)
FT4 before treatment	5.52 ± 1.73 ng/dL
FT3 before treatment	19.50 ± 6.97 pg/mL
Thyroid volume before treatment	27.1 ± 12.5 g
TRAb before treatment	16.0 ± 7.8 IU/L

Table 1. Profile of Subjects (Mean ± SD)

Male:female

13:60

Age

14-67 (median 37)

FT4 before treatment

5.52 ± 1.73 ng/dL

FT3 before treatment

19.50 ± 6.97 pg/mL

Thyroid volume before treatment

27.1 ± 12.5 g

TRAb before treatment

16.0 ± 7.8 IU/L

**Table 2.** Results of Statistical Analysis (Mean ± SD)
	Group A	Group B	P value
All factors were evaluated by Fisher’s exact test or Mann-Whitney U test. “Initially adjusted drugs”, “the duration from initiation of medication to correction of FT4 to normal range” and “adoption of simultaneous reductions of both MMI and KI” showed significant differences between these groups.
Gender (male:female)	26:5	34:8	1.00
Age	35.8 ± 11.9	39.0 ± 12.2	0.23
FT4 before treatment (ng/dL)	5.63 ± 1.72	5.40 ± 1.74	0.64
FT3 before treatment (pg/mL)	20.33 ± 7.14	18.90 ± 6.88	0.48
TRAb before treatment (IU/L)	16.73 ± 8.46	15.39 ± 7.41	0.53
Thyroid volume before treatment (g)	30.13 ± 14.64	24.85 ± 10.19	0.12
Initial dose of MMI (mg)	14.84 ± 1.57	14.17 ± 1.89	0.12
Initially adjusted drugs (MMI:KI)	11:20	4:38	0.009*
FT4 at first adjustment of drugs (ng/dL)	1.36 ± 0.30	1.25 ± 0.38	0.09
The duration from initiation of medication to correction of FT4 to normal range (days)	31.2 ± 18.3	53.9 ± 40.6	0.002*
The duration of administration of KI (days)	55.2 ± 36.9	72.4 ± 56.6	0.15
Methods of adjustment of KI (tapering:cessation without tapering)	16:15	13:29	0.09
Adoption of simultaneous reductions of both MMI and KI (yes:no)	10:21	3:39	0.011*

Table 2. Results of Statistical Analysis (Mean ± SD)

Group A

Group B

P value

All factors were evaluated by Fisher’s exact test or Mann-Whitney U test. “Initially adjusted drugs”, “the duration from initiation of medication to correction of FT4 to normal range” and “adoption of simultaneous reductions of both MMI and KI” showed significant differences between these groups.

Gender (male:female)

26:5

34:8

1.00

Age

35.8 ± 11.9

39.0 ± 12.2

0.23

FT4 before treatment (ng/dL)

5.63 ± 1.72

5.40 ± 1.74

0.64

FT3 before treatment (pg/mL)

20.33 ± 7.14

18.90 ± 6.88

0.48

TRAb before treatment (IU/L)

16.73 ± 8.46

15.39 ± 7.41

0.53

Thyroid volume before treatment (g)

30.13 ± 14.64

24.85 ± 10.19

0.12

Initial dose of MMI (mg)

14.84 ± 1.57

14.17 ± 1.89

0.12

Initially adjusted drugs (MMI:KI)

11:20

4:38

0.009*

FT4 at first adjustment of drugs (ng/dL)

1.36 ± 0.30

1.25 ± 0.38

0.09

The duration from initiation of medication to correction of FT4 to normal range (days)

31.2 ± 18.3

53.9 ± 40.6

0.002*

The duration of administration of KI (days)

55.2 ± 36.9

72.4 ± 56.6

0.15

Methods of adjustment of KI (tapering:cessation without tapering)

16:15

13:29

0.09

Adoption of simultaneous reductions of both MMI and KI (yes:no)

10:21

3:39

0.011*

**Table 3.** Results of Multiple Logistic Regression Analysis
	Odds ratio	CI 95%	P value
Contribution 21%. “The duration from initiation of medication to correction of FT4 to normal range” and “adoption of simultaneous reductions” significantly contributed to transient aggravation of thyroid function after the cessation of KI by multiple logistic regression analysis. However, the proportion contributed by this model was 21%.
Initially adjusted drugs	1.82	0.93-3.79	0.09
The duration from initiation of medication to correction of FT4 to normal range	0.97	0.94-0.99	0.02*
Adoption of simultaneous reductions of both MMI and KI	2.39	1.16-5.73	0.03*

Table 3. Results of Multiple Logistic Regression Analysis

Odds ratio

CI 95%

P value

Contribution 21%. “The duration from initiation of medication to correction of FT4 to normal range” and “adoption of simultaneous reductions” significantly contributed to transient aggravation of thyroid function after the cessation of KI by multiple logistic regression analysis. However, the proportion contributed by this model was 21%.

Initially adjusted drugs

1.82

0.93-3.79

0.09

The duration from initiation of medication to correction of FT4 to normal range

0.97

0.94-0.99

0.02*

Adoption of simultaneous reductions of both MMI and KI

2.39

1.16-5.73

0.03*