Purpose: Intravenous gonadotropin-releasing hormone (IV GnRH) testing is the gold standard for confirming a central precocious puberty (CPP) diagnosis. However, this test is not widely available commercially. Therefore, our study aim was to establish cutoff values for basal gonadotropin level and gonadotrophin responses to a 100-μg subcutaneous IV GnRH test that can distinguish between CPP and premature thelarche (PT) to discover a simple method to detect CPP. Methods: Girls between the ages of 6 and 8 years who attended the pediatric endocrinology outpatient clinic at our tertiary hospital between 2019 and 2022 were included in this study. They were evaluated for breast development, and a subcutaneous 100-μg GnRH test was administered by measuring the luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels in blood samples at baseline and then 30, 60, 90, and 120 minutes after injection. CPP is characterized by increased height velocity, advanced bone age, and progression of breast development. The cutoff value for diagnosis of CPP was determined using a receiver operating characteristic (ROC) analysis. Results: In 86 Thai girls (56 with CPP and 30 with PT), the ROC analysis showed 71.4% and 100% sensitivity and specificity, respectively, for basal LH (cutoff ≥ 0.2 IU/L) plus the basal LH/FSH ratio (cutoff ≥ 0.1). The optimal cutoff values for peak LH (cutoff ≥ 7 IU/L) demonstrated a sensitivity of 94.6% and a specificity of 100%, whereas the LH value at 30 and 60 minutes after injection (cutoff ≥ 6 IU/L) demonstrated sensitivities of 92.9% and 94.6% and a specificity of 100%, respectively Conclusion Combining the basal LH (cutoff: 0.2 IU/L) and the basal LH/FSH ratio (cutoff: 0.1) can easily and cost-effectively diagnose CPP in a girl in breast Tanner stage II.

Objectives. To describe the characteristics of long-standing T1DM in Thai patients and assess residual beta-cell function with status of pancreatic autoantibodies. Methodology. This is a cross-sectional study of Thai subjects with T1DM and disease duration ≥ 25 years seen at the Theptarin Hospital. Random plasma C-peptide and pancreatic auto-antibodies (Anti-GAD, Anti-IA2, and Anti-ZnT8) were measured. Patients who developed complications were compared with those who remained free of complications. Results. A total of 20 patients (males 65%, mean age 49.4±12.0 years, BMI 22.5±3.1 kg/m2, A1C 7.9±1.6%) with diabetes duration of 31.9±5.1 years were studied. Half of the participants remained free from any diabetic complications while the proportions reporting retinopathy, nephropathy, and neuropathy were 40%, 30%, and 15%, respectively. HDL cholesterol was significantly higher and triglyceride concentration significantly lower in patients who were free from diabetic nephropathy but not in those who were free from other complications. The prevalence rates of anti-GAD, anti- IA2, and anti-ZnT8 were 65%, 20%, and 10%, respectively. None of the patients who tested negative for both anti-GAD and anti-IA2 was positive for anti-ZnT8. Residual beta-cell function based on detectable random plasma C-peptide (≥ 0.1 ng/mL) and MMTT was found in only 3 patients (15%). There was no relationship between residual beta-cell function and protective effects of diabetic complications. Conclusion. Endogenous insulin secretion persists in some patients with long-standing T1DM and half of longstanding T1DM in Thai patients showed no diabetic complications. HDL cholesterol was significantly higher and triglyceride concentration significantly lower in patients who were free from diabetic nephropathy
Diabetes Mellitus, Type 1 ; Autoantibodies ; Thailand ; Pancreas ; Insulin-Secreting Cells ; Disease Progression