Higher phthalate concentrations are associated with precocious puberty in normal weight Thai girls.

BACKGROUND: The cause of precocious puberty may be associated with genetics and other conditions such as central nervous system (CNS) insults, or the exposure to endocrine disrupting chemicals (EDCs). Phthalates is known to be one of the EDCs and have estrogenic and antiandrogenic activities, and may be associated with advanced puberty. The objective of the study was to determine the association between urinary phthalate metabolites and advanced puberty. METHODS: A cross-sectional study was conducted in patients with precocious puberty (breast onset <8 years, n=42) and early puberty (breast onset 8-9 years, n=17), compared to age-matched controls (n=77). Anthropometric measurements, estradiol, basal and gonadotropin releasing hormone (GnRH)-stimulated follicle stimulating hormone (FSH) and luteinizing hormone (LH) levels, uterine sizes, ovarian diameters and bone ages (BA) were obtained. Urine samples were collected and mono-methyl phthalate (MMP) and mono-ethyl phthalate (MEP) were analyzed by high performance liquid chromatography (HPLC) and adjusted with urine creatinine. RESULTS: The median adjusted-MEP concentration in girls with precocious puberty, was greater than in normal girls (6105.09 vs. 4633.98 µg/g Cr: p<0.05), and had the same trend among early puberty and normal puberty (5141.41 vs. 4633.98 µg/g Cr: p=0.4), but was not statistically significant. CONCLUSIONS: Precocious puberty girls had an association with increased MEP concentration. This is the first report of the association between urinary phthalate levels and precocious puberty in Thai girls.

Association between urinary phthalates and metabolic abnormalities in obese Thai children and adolescents.

BACKGROUND: Several endocrine disruptors (including phthalates) are considered to be a cause of obesity. However, the current evidence has not conclusively established an association between phthalates and metabolic abnormalities, especially in children. The objective of the study was to evaluate the association between urinary phthalate metabolites and metabolic abnormalities in obese Thai children and adolescents. METHODS: This cross-sectional case-control study was conducted in participants aged 7-18 years and divided into two groups: normal weight and overweight/obesity. Spot urine concentrations of two phthalate metabolites (monomethyl phthalate [MMP] and mono-n-buthyl phthalate [MBP]) were measured by high performance liquid chromatography (HPLC). Anthropometric data, including weight, height, body mass index (BMI), waist circumference (WC), hip circumference (HC), waist-to-hip ratio (WHR) and waist-to-height ratio (WHTR), were measured and calculated. Fasting plasma glucose, insulin, HbA1c, lipid profiles and hepatic transaminase were analyzed, and insulin resistance indices were calculated. RESULTS: One hundred and fifty-five participants were included. The median MMP level in the normal weight and the overweight/obesity groups were 0 (0, 459.83) and 0 (0, 1623.50) µg/g Cr, respectively (p=0.933). The median MBP level in the normal weight and the overweight/obesity groups were 233.6 (118.1, 633.62) and 206.94 (7.4, 427.7) µg/g Cr, respectively (p=0.083). After adjusting for age, gender and puberty, there was no correlation between MBP and all anthropometric data and metabolic profiles. Participants with hypertriglyceridemia had lower MBP levels than those with normal TG level. MMP levels were not significantly different between the participants with normal and abnormal weight of all metabolic parameters. CONCLUSIONS: Participants with hypertriglyceridemia had lower MBP levels than those with normotriglyceridemia. However, it cannot show the correlation between phthalate and metabolic parameters.

Increased levels of bisphenol A (BPA) in Thai girls with precocious puberty.

BACKGROUND: Reports on the secular trend of pubertal onset indicate a recent earlier start especially in girls. Bisphenol A (BPA), which posses estrogenic activity, might be a cause of advanced puberty. The objective of the study was to determine the association between BPA and advanced puberty. METHODS: A cross-sectional study was conducted in patients with advanced puberty (n=41) compared to age-matched controls (n=47). Anthropometric measurements, estradiol, basal and gonadotropin releasing hormone (GnRH)-stimulated follicle stimulating hormone (FSH) and luteinizing hormone (LH) levels, uterine sizes, ovarian diameters and bone ages were obtained. Urinary BPA concentrations were analyzed by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC/MSMS) with the lower limit of quantification (LLOQ) of 0.05 ng/mL. RESULTS: The median adjust-BPA concentration in advanced puberty group was higher than in control groups [1.44 vs. 0.59 µg/g creatinine (Cr): p<0.05]. We also found that the median adjust-BPA concentration in girls with advanced puberty who were overweight/obese, was greater than in the normal pubertal overweight/obese girls (1.74 vs. 0.59 µg/g Cr: p<0.05), and was in the same trend among normal weight girls with advanced and normal puberty (0.83 vs. 0.49 µg/g Cr: p=0.09), but not statistically significant. CONCLUSIONS: The present findings suggest that BPA exposure appears to be related to an earlier age at onset of puberty especially in obese girls.