Peer-reviewed article
First-morning urinary luteinizing hormone and bone age decomposition for diagnosis of central precocious puberty in girls: a two-step prediction model study
Miao Huang, Xiyan Lu, Peipei Liu, 董国庆, 李明洙 et al. ·
Summary
Written by AI, not yet AICS's view · claude-sonnet-5-5This study looked at whether a first-morning urine test for luteinizing hormone (LH) can help diagnose central precocious puberty (early puberty) in girls. Currently diagnosis relies on an invasive blood test that requires a hormone injection (the GnRH stimulation test). The researchers studied 808 children at one centre in China, including 295 girls with early breast development. Urinary LH alone was only moderately accurate, but combining it with age, the gap between bone age and chronological age, breast stage and uterine length gave a better screening model without blood sampling. Adding blood hormone tests improved accuracy further.
Key points
- Urinary LH alone had moderate accuracy for CPP in symptomatic girls (AUC 0.692), highest at ages 7–8 years (AUC 0.708).
- Basal serum LH was a better single marker than urinary LH (AUC 0.868 vs 0.692).
- The noninvasive model (age, bone age minus age, urinary LH, breast stage, uterine length) had a C-statistic of 0.853, with sensitivity 73.3% and specificity 83.2%.
- Adding basal serum LH and FSH raised the C-statistic to 0.909; bootstrap-corrected values were 0.838 and 0.893.
- Pubertal-onset urinary LH cutoffs were >1.02 mIU/mL in girls and >0.95 mIU/mL in boys.
Limitations
This is a single-centre retrospective study, and the abstract reports only internal bootstrap validation, with no external validation. It does not tell us how the test performs in other populations or settings, or whether using it improves outcomes for children.
Abstract
Objective The diagnosis of central precocious puberty (CPP) in girls relies on the invasive gonadotropin-releasing hormone (GnRH) stimulation test. Urinary luteinizing hormone (LH) is a noninvasive candidate biomarker, but evidence from Chinese populations and its integration into multivariable prediction frameworks remain limited. We evaluated the diagnostic accuracy of first-morning urinary LH for CPP, established sex- and pubertal stage–specific reference intervals, and developed a two-step prediction model based on a bone age decomposition. Methods In this single-center retrospective diagnostic accuracy study, we enrolled 808 children: 295 girls with early breast development (146 CPP, 149 non-CPP), 271 healthy girls, and 242 healthy boys (reference intervals only). First-morning urine was assayed for LH, follicle-stimulating hormone (FSH), and creatinine. Diagnostic performance was evaluated primarily in the 295 symptomatic girls, with an extended analysis in 566 girls including healthy controls; multivariable logistic regression decomposed bone age into chronological age (CA) and the BA–CA difference as separate predictors. Results Urinary LH showed moderate accuracy for CPP in the primary symptomatic cohort (AUC 0.692, 95% CI 0.630–0.752), peaking in girls aged 7–8 years (AUC 0.708, 95% CI 0.621–0.785); the extended cohort gave similar results (AUC 0.712; secondary, spectrum-extended estimate). The LH-to-creatinine ratio offered no improvement. Basal serum LH was the superior single marker (AUC 0.868 vs 0.692, P < 0.001). The noninvasive Model 1 (CA + BA–CA + urinary LH + breast Tanner stage + uterine length) achieved a C-statistic of 0.853 (sensitivity 73.3%, specificity 83.2%), with CA, BA–CA, and urinary LH as independent predictors. Adding basal serum LH and FSH (Model 2) improved the C-statistic to 0.909; urinary LH retained independent significance (aOR 1.280, P = 0.024), whereas basal FSH was inversely associated with CPP. Bootstrap-corrected C-statistics were 0.838 (Model 1) and 0.893 (Model 2). Pubertal-onset cutoffs were >1.02 mIU/mL in girls and >0.95 mIU/mL in boys. Conclusions Decomposing bone age into CA and BA–CA enables tiered CPP risk stratification: the noninvasive model supports initial screening without blood sampling, and the complete model refines risk once serum gonadotropins become available. Urinary LH is a clinically useful component of tiered diagnostic algorithms for CPP.