Precocious puberty in Korean girls with and without exposure to endocrine-disrupting chemicals in toy slime: a comparative analysis.

BACKGROUND: Toy slime is popular in Korea, and in parallel, pre-pubertal girls visit hospitals for early pubertal signs. Thus far, numerous studies have investigated the association of endocrine-disrupting chemicals (EDCs) with precocious puberty (PP). However, there is a lack of studies on the clinical manifestations and sex hormones. We aimed to investigate early pubertal development in Korean girls with or without a history of toy slime exposure and determine changes in bone age, Tanner stage, and sex hormones. METHODS: In this study, 140 girls underwent stimulation tests at Kyungpook National University Children's Hospital Endocrinology Department, during January 2018 and December 2020. Patients were divided into two groups for gonadotropin-releasing hormone (GnRH) stimulation test and frequency of exposure to toy slime (EDCs). GnRH stimulation test was conducted after an intravenous injection of 100 µg of luteinizing hormone-releasing hormone. Slime exposure was defined as Slime ≥ 3 times/week for ≥ 3 months. RESULTS: History of slime exposure was found in 14 of 58 and 65 of 82 patients in the central PP (CPP) and non-CPP groups, respectively. Slime-exposed patients had advanced bone age, although their Tanner stage was low. Patients with a history of toy slime exposure were 5.5 times more likely to be diagnosed with non-CPP than patients without slime exposure (p < 0.05). CONCLUSIONS: Exposure to toy slime in prepubertal girls may be associated with rapid clinical advancement of pubertal development and bone age, and the patients appear more likely to be diagnosed with non-CPP.

An Alport syndrome boy with Van Wyk-Grumbach syndrome induced by prolonged untreated congenital hypothyroidism.

Alport syndrome (AS) is a rare genetic disorder that causes progressive nephritis and is more common among males. Studies have reported an association between thyroid antibodies and hypothyroidism in patients with AS, but the relevance of this relationship is under debate. Prolonged untreated hypothyroidism induces short stature, abnormal pubertal development, and various other symptoms. However, children with long-standing hypothyroidism rarely present with signs of precocious puberty, or Van Wyk-Grumbach syndrome (VWGS). We report the case of a boy, 8 years and 4 months old, who had VWGS caused by prolonged untreated congenital hypothyroidism and AS. The boy had repeated gross hematuria and proteinuria and was diagnosed with AS by renal biopsy and genetic testing. He had normal renal function but severe growth retardation and hypothyroidism. Obesity, bone age delay, hyperlipidemia, and abnormal increased testicle size were also present due to prolonged untreated hypothyroidism. His thyroid antibody titer elevation was unclear, although ultrasonography and thyroid scanning showed a decrease in thyroid volume. We diagnosed the patient with congenital hypothyroidism caused by thyroid dysgenesis. VWGS was diagnosed due to hypothyroidism, delayed bone age, and pseudoprecocious puberty. To the best of our knowledge, this is the first report of a prepubertal Korean boy with prolonged untreated congenital hypothyroidism complicated by VWGS in AS.

Severe vitamin D deficiency in preterm infants: maternal and neonatal clinical features.

PURPOSE: We investigated the vitamin D status of preterm infants to determine the incidence of vitamin D deficiency. METHODS: A total of 278 preterm infants delivered at Kyungpook National University Hospital between January 2013 and May 2015 were enrolled. The serum concentrations of calcium, phosphorous, alkaline phosphatase, and 25-hydroxyvitamin D (25-OHD) were measured at birth. We collected maternal and neonatal data such as maternal gestational diabetes, premature rupture of membranes, maternal preeclampsia, birth date, gestational age, and birth weight. RESULTS: Mean gestational age was 33(+5)±2(+2) weeks of gestation and mean 25-OHD concentrations were 10.7±6.4 ng/mL. The incidence of vitamin D deficiency was 91.7%, and 51.1% of preterm infants were classified as having severe vitamin D deficiency (25-OHD<10 ng/mL). The serum 25-OHD concentrations did not correlate with gestational age. There were no significant differences in serum 25-OHD concentrations or incidence of severe vitamin D deficiency among early, moderate, and late preterm infants. The risk of severe vitamin D deficiency in twin preterm infants was significantly higher than that in singletons (odds ratio, 1.993; 95% confidence interval [CI], 1.137-3.494, P=0.016). In the fall, the incidence of severe vitamin D deficiency decreased 0.46 times compared to that in winter (95% CI, 0.227-0.901; P=0.024). CONCLUSION: Most of preterm infants (98.9%) had vitamin D insufficiency and half of them were severely vitamin D deficient. Younger gestational age did not increase the risk of vitamin D deficiency, but gestational number was associated with severe vitamin D deficiency.