BACKGROUND AND OBJECTIVE

Transient congenital hypothyroidism (TCH) refers to temporary deficiency of thyroid hormone identified after birth which later recovers to improved thyroxine production. Its prevalence in the Philippines has not been reported in a large-scale study. Its diagnosis remains difficult due to its numerous possible etiologies. Identifying the predictive factors of TCH may aid in earlier diagnosis and decreased risk of overtreatment. This study aimed to determine the predictive factors for TCH in children with congenital hypothyroidism (CH) detected by newborn screening (NBS) in the Philippines from January 2010 to December 2017.

In this multicenter retrospective cohort study involving 15 NBS continuity clinics in the Philippines, medical records were reviewed, and clinical and laboratory factors were compared between children with TCH and those with permanent congenital hypothyroidism (PCH). Of the 2,913 children diagnosed with CH in the Philippines from 2010 to 2017, 1,163 (39.92%) were excluded from the study due to an unrecalled or lost to follow-up status, or a concomitant diagnosis of Down Syndrome.

Among the 1,750 patients included in analysis, 6.97% were diagnosed with TCH, 60.80% were female, mean gestational age at birth was 38 weeks, and mean birth weight was 2,841 grams. Confirmatory thyrotropin (TSH) was lower and confirmatory free thyroxine (FT4) was higher in the TCH group compared to those with PCH (TSH 32.80 vs 86.65 µIU/mL [p < 0.0001]; FT4 9.90 vs 7.37 pmol/L [p 0.001]). The TCH group required lower L-thyroxine doses compared to the PCH group at treatment initiation and at 1, 2, and 3 years of age (initial 6.98 vs 12.08 µg/ kg/day [p < 0.0001]; at 1 year 1.89 vs 4.11 µg/kg/day [p < 0.0001]; at 2 years 1.21 vs 3.72 µg/kg/day [p < 0.0001]; at 3 years 0.83 vs 3.45 µg/kg/day [p < 0.0001]). Among those with TCH, mean serum TSH decreased significantly after treatment with L-thyroxine (32.80 vs. 6.55 µIU/ mL, p 0.0001). Other factors associated with TCH were results of thyroid ultrasonography (p 0.007), gestational age at birth (p 0.02), and maternal history of thyroid illness (p < 0.0001).

Of all the patients with confirmed congenital hypothyroidism via the newborn screening, 6.97% were diagnosed with transient CH. Factors associated with TCH are confirmatory TSH and FT4, L-thyroxine dose requirements, thyroid ultrasound findings, gestational age at birth, and a maternal history of thyroid illness.

BACKGROUND AND OBJECTIVE

Transient congenital hypothyroidism (TCH) refers to temporary deficiency of thyroid hormone identified after birth which later recovers to improved thyroxine production. Its prevalence in the Philippines has not been reported in a large-scale study. Its diagnosis remains difficult due to its numerous possible etiologies. Identifying the predictive factors of TCH may aid in earlier diagnosis and decreased risk of overtreatment. This study aimed to determine the predictive factors for TCH in children with congenital hypothyroidism (CH) detected by newborn screening (NBS) in the Philippines from January 2010 to December 2017.

In this multicenter retrospective cohort study involving 15 NBS continuity clinics in the Philippines, medical records were reviewed, and clinical and laboratory factors were compared between children with TCH and those with permanent congenital hypothyroidism (PCH). Of the 2,913 children diagnosed with CH in the Philippines from 2010 to 2017, 1,163 (39.92%) were excluded from the study due to an unrecalled or lost to follow-up status, or a concomitant diagnosis of Down Syndrome.

Among the 1,750 patients included in analysis, 6.97% were diagnosed with TCH, 60.80% were female, mean gestational age at birth was 38 weeks, and mean birth weight was 2,841 grams. Confirmatory thyrotropin (TSH) was lower and confirmatory free thyroxine (FT4) was higher in the TCH group compared to those with PCH (TSH 32.80 vs 86.65 µIU/mL [pCONCLUSION

Of all the patients with confirmed congenital hypothyroidism via the newborn screening, 6.97% were diagnosed with transient CH. Factors associated with TCH are confirmatory TSH and FT4, L-thyroxine dose requirements, thyroid ultrasound findings, gestational age at birth, and a maternal history of thyroid illness.

BACKGROUND: Subclinical hypothyroidism (SCH) has been reported to be associated with lower endothelial progenitor (CD34-positive) cell count, whereas an inverse association between circulating CD34-positive cell count and height loss is documented. Reports indicate height loss to be associated with all-cause mortality, and a higher CD34-positive cell count has been shown to predict longer life. Therefore, evaluating the association between SCH and height loss provides mechanistic insights underlying the association between height loss and mortality risk. METHODS: A prospective study involving 1,599 participants with normal free triiodothyronine (T3) and free thyroxine (T4) levels was conducted to determine the association between SCH and height loss.Since the free T4 level influences the supply of active thyroid hormone (free T3), the analysis was stratified by the median free T4 level. Height loss was defined as the highest quintile of annual height decrease. RESULTS: SCH was positively associated with height loss in participants with low-normal free T4 levels (below the median), but not in those with high-normal free T4 levels (at or above the median). After adjusting for sex, age, free T3 level, atherosclerosis, and known cardiovascular risk factors, the adjusted odds ratios (95% confidence interval) for height loss were 1.88 (1.02, 3.47) and 1.92 (1.02, 3.62) in the low-normal free T4 group. The corresponding values in the high-normal free T4 group were 0.37 (0.08, 1.69) and 0.43 (0.09, 1.97). CONCLUSION SCH could influence height loss, and free T4 might influence the association between SCH and height loss in euthyroid individuals. These results clarify the mechanisms underlying the association between height loss and mortality risk.
Humans ; Hypothyroidism/epidemiology* ; Thyroxine/blood* ; Male ; Female ; Prospective Studies ; Middle Aged ; Body Height ; Adult ; Aged ; Risk Factors

Objective: This study aims to determine the effect of iodine excess in pregnant mothers on thyroid function, growth and neurodevelopment in the neonates when assessed at 12 weeks of age. Methodology: This prospective study enrolled term neonates with birth weight >2500 gm of mothers having urine iodine concentration (UIC) ≥500 µg/L documented in the third trimester of the peripartum period. Neonatal TSH was collected by heel prick on dried blood spots within 24-72 hours of age and measured by time-resolved fluroimmunoassay. Neonates with TSH ≥11 mIU/L at birth were followed up at 2 and 12 weeks to monitor thyroid dysfunction, growth and development. Results: A total of 2354 (n = 1575 in the delivery room) maternal urine samples were collected of which 598 (25.4%) had elevated UIC. Forty-nine (12.2%) neonates had TSH ≥11mIU/L on newborn screening of whom 18 and 3 neonates had residual elevated TSH at 2 and 12 weeks of life, respectively. Maternal iodine levels correlated weakly with TSH at 2 weeks (rho = 0.299; p = 0.037). No child required treatment for congenital hypothyroidism. Eight babies additionally had TSH >5 mIU/L at 12 weeks of life. The growth and development of babies with or without TSH elevation was comparable at three months (p > 0.05). Conclusion Maternal iodine excess in pregnancy and peripartum period causes transient hyperthyrotropinemia in neonates that did not affect the growth and development at 3 months of age.
Thyroid ; Thyroid Gland ; Hypothyroidism ; Thyroid Function Tests

OBJECTIVES

This study aimed to determine the clinical profile of non thyroidal cancer patients with thyroid dysfunction associated with tyrosine kinase inhibitor (TKI) therapy at the University of Santo Tomas Hospital (USTH), Philippines.

This is a retrospective observational study of TKI initiated adult non-thyroidal cancer patients with thyroid function testing from 2013 to 2018.

Forty percent (95% CI: 26.2% - 58.61%) of the sixty individuals who had thyroid function tests (TFT) had incident thyroid dysfunction. Thirty percent had hypothyroidism (i.e., 25% overt [mean TSH 16.64 uIU/mL]; 5% subclinical [mean TSH 6.62 uIU/mL]). The median time at risk was 8 and 16 months for overt and subclinical hypothyroidism, respectively. Fifty-six percent had persistent hypothyroidism (median TSH 16.75, p = 0.009). The average time to recovery of transient hypothyroidism was 39 months. Ten percent had hyperthyroidism with a median time at risk of 1.5 months. Non-small cell lung cancer and renal cell carcinoma were possible associated risk factors of thyroid dysfunction.

TKI-induced thyroid dysfunctions are common. Screening and monitoring for thyroid abnormalities during TKI therapy is important.

Objectives: We determined the clinical characteristics and prevalence of metabolic syndrome among adult Filipinos with overt hypothyroidism. Methodology: This is a cross-sectional study of 151 adults. Patients were recruited by sequential enrollment. Anthropometric and blood pressure measurements were performed followed by blood extraction for metabolic parameters and thyroid function tests. Clinical and laboratory characteristics were compared between patients with and without metabolic syndrome. Results: The prevalence of metabolic syndrome is 40.4% (95%CI: 32.5%, 48.7%). Patients with metabolic syndrome have a waist circumference of 88.4 ± 7.7 cm in females and 93.3 ± 9.0 cm in males. The median fasting blood glucose was 111.4 (52.2) mg/dL, median systolic blood pressure of 120 (30) mm Hg and diastolic blood pressure of 80 (20) mmHg, median serum triglycerides of 174.3 (114.2) mg/dL, median HDL-C of 42.3 (19.2) mg/dL and a proportion of patients with diabetes (23.0%) and hypertension (44.3%), respectively. The presence of increased waist circumference is the most prevalent component seen among hypothyroid patients. There were no differences in terms of age, sex, etiology of hypothyroidism and anti-TPO levels in those with and without metabolic syndrome. Conclusion The prevalence of metabolic syndrome in adult Filipinos with hypothyroidism is high. Emphasis must be placed on early screening using waist circumference and metabolic parameters among hypothyroid patients who are at high risk of developing metabolic syndrome.
Dyslipidemias ; Hypothyroidism ; Metabolic Syndrome ; Prevalence

Infants of mothers with Graves’ disease (GD) may develop central hypothyroidism (CH) due to exposure of the foetal hypothalamic-pituitary-thyroid axis to higher-than-normal thyroid hormone concentrations, primary hypothyroidism (PH) due to transplacental passage of maternal thyroid stimulating hormone receptor antibody (TRAb), antithyroid drugs (ATD) or thyroid dysgenesis secondary to maternal uncontrolled hyperthyroidism. We describe two infants with PH and four infants with CH born to mothers with poorly controlled Graves' disease. All infants required levothyroxine and had normal developmental milestones. While national guideline consensus for high thyroid stimulating hormone (TSH) on neonatal screening is well-established, thyroid function tests (TFTs) should be serially monitored in infants with low TSH on screening, as not all mothers with Graves’ disease are diagnosed antenatally.
Infant ; Hypothyroidism ; Congenital Hypothyroidism

Congenital disorders cause a global estimate of 240,000 deaths in newborns and 170,000 deaths in children ages 1 month up to 5 years every year. 1 In order to detect metabolic, hematologic, or endocrine disorders in newborns, newborn screening (NBS) is conducted in many countries around the world. In the Philippines, NBS was introduced by the Newborn Screening Study Group in 1996, with the aim of establishing the incidence of six metabolic conditions, namely, congenital hypothyroidism, congenital adrenal hyperplasia, galactosemia, phenylketonuria, homocystinuria, and glucose-6-phosphate dehydrogenase deficiency, and creating recommendations for the adoption of NBS nationwide.2 The Republic Act No. 9288, otherwise known as the Newborn Screening Act of 2004, requires that the Department of Health shall ensure the establishment and accreditation of newborn screening centers (NSCs) in strategically located areas across the Philippines.3 At present, there are seven operational NSCs in the country,4 with the Newborn Screening Center-Mindanao (NSC-Mindanao) in Southern Philippines Medical Center (SPMC) as the only center catering to all NBS facilities all over Mindanao.5 NSC-Mindanao initially performed screening tests for five disorders, but now tests for a panel of 29 metabolic and other congenital disorders.
Neonatal Screening ; Adrenal Hyperplasia, Congenital ; Glucosephosphate Dehydrogenase Deficiency ; Congenital Hypothyroidism

BACKGROUND: More than 75 million procedures with intravascular iodine-based contrast media (ICM) are performed worldwide every year, and some patients undergoing these procedures do not have normal thyroid function. The long-term effects of ICM in patients with mild thyroid dysfunction (TD) are unclear. METHODS: This prospective cohort study was conducted in China. Patients with stable angina pectoris with total triiodothyronine (TT3) reduction, normal thyroid-stimulating hormone, and reverse triiodothyronine (rT3) were enrolled and divided into high-dose (≥100 mL ICM) and low-dose groups (<100 mL ICM). We dynamically investigated the trends in thyroid function, rT3, and thyroid antibodies one year after ICM exposure. RESULTS: A total of 154 patients completed 6 months of follow-up and 149 completed 1 year of follow-up. Thyroglobulin antibody (TGAB) levels were elevated in 41 (26.6%) patients before ICM exposure, 11 (7.1%) of whom also had elevated thyroid peroxidase antibody levels. Transient subclinical TD occurred 6 months after ICM exposure; 75.5% (34/45) of post-operative TD occurred in the high-dose group. One patient developed severe hypothyroidism with myxedema, requiring drug intervention 1 year after ICM exposure. The level of rT3 showed no statistically significant changes during post-operative follow-up ( P  = 0.848). The TGAB level decreased at 6th month ( P  < 0.001), but increased at 1 year after ICM exposure ( P  = 0.002). CONCLUSIONS Patients with T3 reduction are at a risk of transient subclinical TD and hypothyroidism after a single large dose of ICM. Follow-up of this population at 9-12 months after ICM exposure is warranted.
Humans ; Contrast Media/adverse effects* ; Prospective Studies ; Hypothyroidism ; Triiodothyronine ; Iodine/adverse effects* ; Thyrotropin ; Thyroxine

OBJECTIVES: To analyze the results of neonatal screening for congenital hypothyroidism (CH) and hyperphenylalaninemia (HPA) in Zhejiang province from 1999 to 2022. METHODS: A total of 11 922 318 newborns were screened from September 1999 and December 2022 in Zhejiang province. The blood thyroid stimulating hormone (TSH) levels were measured by a fluorescence method and blood phenylalanine (Phe) levels were measured by fluorescence method or tandem mass spectrometry. TSH≥9 μIU/mL was considered positive for CH, while Phe>120 μmol/L and/or Phe/Tyr ratio>2.0 were considered positive for HPA. The positive newborns in screening were recalled, and the gene variations were detected by high-throughput sequencing and MassARRAY tests. RESULTS: The overall neonatal screening rate during 1999-2022 was 89.41% (11 922 318/13 333 929) and the screening rate was increased from 6.46% in 1999 to 100.0% in 2022. A total of 8924 cases of CH were diagnosed among screened newborns with an incidence rate of 1/1336. A total of 563 cases of HPA were diagnosed, including 508 cases of classic phenylketonuria (cPKU) and 55 cases of tetrahydrobiopterin deficiency (BH4D), with an incidence rate of 1/21 176. Ninety-seven out of 8924 cases of CH underwent genetic analysis. Gene mutations were detected in 9 CH related genes, the highest frequency mutations were found in DUOX2 gene (69.0%) with c.3329G>A (p.R1110Q) (18.2%) and c.1588A>T (p.K530X) (17.3%) as the hotspot mutations. There were 81 PAH gene variants detected in a total of 250 cases of cPKU, and c728G>A (p.R243Q) (24.4%), c.721C>T (p.R241C) (15.0%) were the hotspot mutations. Meanwhile 7 novel variants in PAH gene were detected: c.107C>A (p.S36*), c.137G>T (p.G46V), c.148A>G(p.K50E), c.285C>T (p.I95I), c.843-10delTTCC, exon4-7del and c.1066-2A>G. There were 12 PTS gene variants detected in 36 cases of BH4D, and c.259C>T (p.P87S) (31.9%) was the hotspot mutation. CONCLUSIONS The incident of CH has increased from 1999 to 2022 in Zhejiang province, and it is higher than that of national and global levels; while the incidence of HPA is similar to the national average. DUOX2 gene variation is the most common in CH patients; c.728G>A (p.R243Q) is the hotspot mutation in cPKU patients, while c.259C>T (p.P87S) is the hotspot mutation in BH4D patients.
Humans ; Infant, Newborn ; Neonatal Screening ; Dual Oxidases ; Congenital Hypothyroidism/genetics* ; Phenylketonurias/genetics* ; Thyrotropin