Increasing the Radioiodine Dose Does Not Improve Cure Rates in Severe Graves' Hyperthyroidism: A Clinical Trial with Historical Control

Table 2

Baseline characteristics of patients with Graves’ hyperthyroidism and a thyroid volume ≥48 mL, grouped by response to ¹³¹I therapy.

	Cure (𝑛=19)	Failure (𝑛=11)	𝑃
Sex (F/M)	14/5	9/2	1.000
Age (years)	30.7±8.2	39.2±7.3	0.008
BMI (Kg/m²)	22.5±3.0	23.3±4.0	0.534
Smokers [𝑛 (%)]	9 (47)	4 (36)	0.708
Methimazole [𝑛 (%)]	8 (42)	5 (45)	1.000
OC [n (% of females)]	9 (64)	2 (22)	0.080
Thyroid volume (mL)	61.1±12.5	63.1±11.3	0.656
24 h-RAIU (%)	77.2±11.2	79.1±19.2	0.771
Basal T4 (nmol/L)	355±127	324±91	0.493
Basal T4L (pmol/L)	80±31	63±28	0.188
Basal T3 (nmol/L)	8.7 (5.6–10.8)	10.0 (9.1–14.0)	0.121
^131I dose (mCi)	18.3±4.2	19.0±5.2	0.675

The values are the mean ± SD or median (25–75%). BMI: body mass index; OC: oral contraceptive; 24 h-RAIU: 24-hour radioiodine uptake.
The reference ranges for laboratory values are T4, 56.3–160.9 nmol/Liter (4.5–12.5 μg/dL); free T4, 8.4–23.2 pmol/Liter (0.6–1.8 ng/dL); and T3, 1.19–2.8 nmol/Liter (78–182 ng/dL).
To convert T4 values to micrograms per dL and free T4 values to nanograms per dL, values should be divided by 12.87. To convert T3 values to nanograms per dL, values should be divide by 0.01536.