Prediction models constructed for Hashimoto's thyroiditis risk based on clinical and laboratory factors

BACKGROUND

Hashimoto's thyroiditis (HT) frequently occurs among autoimmune diseases and may simultaneously appear with thyroid cancer. However, it is difficult to diagnose HT at an early stage just by clinical symptoms. Thus, it is urgent to integrate multiple clinical and laboratory factors for the early diagnosis and risk prediction of HT.

METHODS

We recruited 1,303 participants, including 866 non-HT controls and 437 diagnosed HT patients. 44 HT patients also had thyroid cancer. Firstly, we compared the difference in thyroid goiter degrees between controls and patients. Secondly, we collected 15 factors and analyzed their significant differences between controls and HT patients, including age, body mass index, gender, history of diabetes, degrees of thyroid goiter, UIC, 25-(OH)D, FT3, FT4, TSH, TAG, TC, FPG, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol. Thirdly, logistic regression analysis demonstrated the risk factors for HT. For machine learning modeling of HT and thyroid cancer, we conducted the establishment and evaluation of six models in training and test sets.

RESULTS

The degrees of thyroid goiter were significantly different among controls, HT patients without cancer (HT-C), and HT patients with thyroid cancer (HT+C). Most factors had significant differences between controls and patients. Logistic regression analysis confirmed diabetes, UIC, FT3, and TSH as important risk factors for HT. The AUC scores of XGBoost, LR, SVM, and MLP models indicated appropriate predictive power for HT. The features were arranged by their importance, among which, 25-(OH)D, FT4, and TSH were the top three high-ranking factors.

CONCLUSIONS

We firstly analyzed comprehensive factors of HT patients. The proposed machine learning modeling, combined with multiple factors, are efficient for thyroid diagnosis. These discoveries will extensively promote precise diagnosis, personalized therapies, and reduce unnecessary cost for thyroid diseases.

Iodine monitoring models contribute to avoid adverse birth outcomes related more than adequate iodine intake

BACKGROUND

Iodine plays an important role in pregnancy. How to maintain adequate iodine intake amongst pregnant women in each trimester of pregnancy to prevent adverse birth outcomes in central China is a challenge for clinical practice.

METHODS

870 pregnant women and their infants were enrolled in the study. Urinary iodine concentration (UIC) was measured using an inductively coupled plasma mass spectrometry (ICP-MS). Maternal and newborn information were obtained during follow-up. Multinomial logistic regression models were established.

RESULTS

Median UIC of pregnant women was 172 ± 135 μg/L which is currently considered to be sufficient. Multivitamin supplements containing iodine, iodized salt intake and frequent milk intake were significantly associated with higher UIC. Multivariate logistic regression analysis showed that multivitamin supplements containing iodine and milk consumption were risk factors for more than adequate iodine (UIC ≥ 250 μg/L). Iodine-rich diet was significantly related to heavier birthweight, larger head circumference and longer femur length of the newborns while more than adequate iodine intake (UIC ≥ 250 μg/L) was a risk factor for macrosomia. Logistic regression models based on potential risk factors involving iodine containing supplements and iodine-rich diet were established to predict and screen pregnant women with high risk of more than adequate iodine intake among local pregnant women in different trimesters and guide them to supplement iodine reasonably to prevent the risk.

CONCLUSIONS

Multivitamin supplements containing iodine and milk consumption were risk factors for maternal UIC ≥ 250 μg/L which was a risk factor for macrosomia. Iodine monitoring models were established to provide guidance for pregnant women to reduce the risk of more than adequate iodine intake, thereby contributing to reduce the risk of having a macrosomia.

Vitamin D and iodine status was associated with the risk and complication of type 2 diabetes mellitus in China

The purpose of this study was to assess the relationship between 25-hydroxyvitamin D (25(OH)D), urinary iodine concentration (UIC), and type 2 diabetes mellitus (T2DM) risk and complications and to establish a model to predict T2DM in the general population. A total of 567 adults (389 T2DM patients and 178 controls) were enrolled, and the levels of 25(OH)D, iodine, and blood biochemical parameters were measured. Pearson’s correlation analysis showed an inverse correlation between 25(OH)D level, UIC, and T2DM risk. Low 25(OH)D level was a risk factor for developing T2DM (OR, 0.81; 95% CI, 1.90–2.63; P = 0.043) after adjustment for multiple risk factors. 25(OH)D level and UIC were inversely correlated with short-term and long-term glucose levels. 25(OH)D deficiency was also associated with a high incidence of T2DM complicated with thyroid dysfunction. A prediction model based on 25(OH)D, iodine status, and other risk factors was established and recommended to screen high-risk T2DM in the general population and provide early screening and timely treatment for them.

Reference intervals of thyroid hormones during pregnancy in Korea, an iodine-replete area

BACKGROUND/AIMS

Maternal thyroid dysfunction has been associated with adverse pregnancy outcomes. The purpose of our study was to establish trimester-specific reference intervals for thyroid hormones in pregnant women in Korea, where iodine intake is more than adequate and to examine pregnancy and perinatal outcomes in their offspring.

METHODS

Among 459 healthy pregnant women who were screened, we enrolled 417 subjects who had negative results for thyroid autoantibodies. Serum thyroid stimulating hormone (TSH) and free thyroxine were measured using an immunoradiometric assay. Urine iodine concentration was measured using inductively coupled plasma-mass spectrometry in 275 women. Reference ranges of thyroid hormones were determined according to the guidelines of the National Academy of Clinical Biochemistry. Pregnancy and perinatal outcomes were compared according to maternal thyroid function.

RESULTS

The reference ranges of serum TSH were 0.03 to 4.24 mIU/L in the first trimester, 0.13 to 4.84 mIU/L in the second trimester, and 0.30 to 5.57 mIU/L in the third trimester. Pregnancy and perinatal outcomes did not vary in mothers with subtle changes in thyroid function.

CONCLUSIONS

Trimester-specific thyroid hormone reference intervals in Korean pregnant women differ from those of other countries with different iodine nutrition status and ethnicity. The establishment of population-based, reliable trimester-specific reference intervals is critical for the interpretation of thyroid function in pregnant women to avoid unnecessary tests and treatments.

Iodine intake as a risk factor for BRAF mutations in papillary thyroid cancer patients from an iodine-replete area

PURPOSE

Both deficient and excessive iodine intake leads to thyroid disease, which shows U-shaped curves. Our previous study showed that a relatively low [urinary iodine concentration (UIC) <300 μg/L] and extremely excessive (UIC ≥ 2500 μg/L) iodine intake were associated with thyroid cancer in Korea, an iodine-replete area. Papillary thyroid cancer (PTC) accounts for more than 97 % of thyroid cancer and 80% or more PTC cases harbor the BRAF mutation in Korea. We aimed to investigate the relationship between iodine intake and the prevalence of the BRAF mutation in PTC in Korea.

METHODS

UIC was measured by inductively coupled plasma mass spectrometry. The BRAF mutation was detected using both allele-specific polymerase chain reaction and mutant enrichment with 3'-modified oligonucleotide sequencing. Risk factors for the occurrence of BRAF mutations in PTC were evaluated using multivariate logistic regression models.

RESULTS

The median UIC in all patients with PTC was 287 μg/L (range from 7 to 7, 426 μg/L). Nearly half of the patients (102/215, 47%) belonged to the excessive iodine intake category (UIC ≥ 300 μg/L) according to the WHO iodine recommendations. The frequency of BRAF mutations was lowest in the 300-499 μg/L UIC group; it was significantly different compared to the relatively low (UIC < 300 μg/L) and more than excessive (UIC ≥ 500 μg/L) iodine intake groups. UIC was an independent predictor for BRAF mutations in PTC. The multivariate-adjusted odds ratios (95% confidence intervals) in the relatively low and more than excessive iodine intake groups for the BRAF mutation were 4.761 (1.764-12.850) and 6.240 (2.080-18.726), respectively, compared to the 300-499 μg/L UIC group.

CONCLUSION

Relatively low iodine intake and more than excessive iodine intake seem to be significant risk factors for the occurrence of BRAF mutations in the thyroid and, therefore, may be risk factors for the development of PTC in an iodine-replete area.

Excessive iodine intake does not increase the recurrence rate of graves' disease after withdrawal of the antithyroid drug in an iodine-replete area

BACKGROUND AND OBJECTIVES

The relationship between iodine intake and effects of antithyroid drugs (ATD) for Graves' disease, especially in iodine-deficient areas, has been demonstrated in many studies. However, it was not clear how chronic high iodine intake influenced the effectiveness of ATD in an iodine-replete area. This study aimed to clarify the effect of iodine intake on clinical outcomes of Graves' disease after discontinuation of ATD in Korea, an iodine-replete area.

METHODS

A total of 142 patients with Graves' disease who visited the outpatient clinic regularly and stopped their ATD between October 2011 and April 2013 were enrolled in our study. Urinary iodine concentration (UIC) was measured just before and after the discontinuation of ATD.

RESULTS

Median UIC was not significantly different between the remission and relapse groups, as well as among the four treatment groups (group 1, remission after initial treatment; group 2, remission after repeated treatment; group 3, early relapse within a year; group 4, late relapse after a year). Remission rates did not show a significant difference between the excessive iodine intake (UIC ≥300 μg/l) and average iodine intake groups (UIC <300 μg/l).

CONCLUSIONS

The present study suggests that excessive iodine intake does not have an effect on the clinical outcomes of Graves' disease in an iodine-replete area, and therefore diet control with iodine restriction might not be necessary in the management of Graves' disease.

The impact of iodinated contrast agent administered during preoperative computed tomography scan on body iodine pool in patients with differentiated thyroid cancer preparing for radioactive iodine treatment

BACKGROUND

Iodine in iodinated contrast agents (ICAs) interferes with radioactive iodine treatment (RAIT) and diagnostic scans in patients with differentiated thyroid carcinoma (DTC) because it can compete with ¹³¹I. Published guidelines recommend delaying RAIT for three to four months in patients who have been exposed to ICA. Spot urinary iodine concentration is a useful marker to reflect the body iodine pool. We investigated the impact of ICAs administered at preoperative computed tomography (CT) scan on the body iodine pool to determine the proper time interval between preoperative CT and RAIT in DTC patients.

METHODS

We performed a retrospective review of 1023 patients with DTC who underwent a preoperative CT scan with ICA, total thyroidectomy, and one week of low-iodine diet in preparation for RAIT. Urine iodine excretion (UIE) was measured in spot urine by inductively coupled plasma mass spectrometry and reported both in simple concentration (μg/L) and divided by gram creatinine (μg/gCr). Patients were divided into five groups by time interval in days between preoperative CT scan and spot urine iodine measurement (A, 31-60 [n=29]; B, 61-90 [n=155]; C, 91-120 [n=546]; D, 121-150 [n=226]; E, 151-180 [n=67]).

RESULTS

The median (interquartile range) of UIE (μg/gCr) in each group was 44.4 (27.7-73.2) in group A, 33.3 (22.8-64.7) in group B, 32.7 (20.8-63.0) in group C, 32.0 (20.6-67.0) in group D, and 30.4 (19.6-70.8) in group E. There was no significant difference between group A and the remaining groups (p>0.05) Also, the proportion of patients who achieved the appropriate UIE for RAIT according to our hospital's cutoff (≤66.2 μg/gCr) was not different between groups (A, 72.4%; B, 76.1%; C, 77.5%; D, 74.8%; E, 74.6%) (p=0.78).

CONCLUSION

This study shows that a UIE of one month after preoperative CT scan with ICA was not higher than that of six months after CT scan in patients who underwent total thyroidectomy for DTC. Thus, current guidelines that recommend delay of RAIT for three to four months after CT scan with ICA should be revisited and future studies to clarify the appropriate time interval between CT scan with ICA and RAIT are warranted.

Iodine status in Korean preschool children as determined by urinary iodine excretion

PURPOSE

Iodine is a trace element of thyroid hormones. Excessive or insufficient iodine intake is associated with various thyroid diseases. Urinary iodine (UI) is a sensitive indicator and a recommended barometer of population iodine intake. In Korea, there has been no available data regarding iodine intake in preschool children. We investigated the iodine intake status of Korean preschool children through examination of their UI.

METHODS

This cross-sectional study was performed in 611 healthy preschool children (302 from Seoul and 309 from Masan), aged from 2 to 7 in 2010. UI concentration was measured by inductively coupled plasma-mass spectrometry.

RESULTS

The median UI concentration was 438.8 μg/L. Insufficient iodine intakes (<100 μg/L) were seen in 24 children (3.9%), and excessive iodine ingestion (>300 μg/L) was found in 406 children (66.4%). There were no significant differences in UI between different sexes and ages. Additionally, the median UI concentration was higher in children from Seoul (512.2 μg/L) than that in children from Masan (362.4 μg/L, P < 0.001).

CONCLUSION

About two-thirds of Korean preschool children were in the state of excessive iodine intake, and 3.9% of children showed insufficient iodine intake. Preventive measures and follow-up for iodine intake in preschool children are needed.