INSL3 as a Biomarker of Pubertal Activation: Role in Evaluating Precocious and Delayed Puberty (INSL3GNRH)

September 30, 2026 updated by: Federico Baronio, IRCCS Azienda Ospedaliero-Universitaria di Bologna

INSL3 as an Early Marker of Pubertal Activation: Evaluation of Its Potential Role as a New Biomarker in the Diagnosis of Central Precocious Puberty and Delayed Puberty.

This is an observational study in children up to 16 years old who are suspected of having central precocious puberty or delayed puberty. The main questions it aims to answer are:

  • Can the level of insulin-like peptide 3 (INSL3) predict if a child's puberty has truly started?
  • Can this marker help reduce the need for more complex and invasive tests?

Participants will:

  • Give one extra blood sample just before starting the standard gonadotropin-releasing hormone (GnRH) stimulation test (during the baseline blood draw).
  • Have this extra sample used to measure the INSL3 hormone.
  • Complete the rest of the GnRH test as prescribed by their doctor.

Researchers will compare the INSL3 hormone levels in children who have a positive GnRH test to those who have a negative test. This will help researchers learn if INSL3 can be used as a new, simple tool to diagnose early or delayed puberty.

Study Overview

Status

Recruiting

Conditions

Detailed Description

Diagnosing the exact onset of puberty, especially in its early stages, is a clinical challenge. Currently, the gonadotropin-releasing hormone (GnRH) stimulation test is the gold standard for evaluating hypothalamic-pituitary-gonadal (HPG) axis activation. However, this test is invasive, time-consuming, expensive, and may have limited sensitivity during the very early phases of Central Precocious Puberty (CPP) or Delayed Puberty (DP).

INSL3 is produced constitutively by Leydig cells in males and theca cells of growing antral follicles in females. Unlike other hormones which are secreted with acute and pulsatile patterns, INSL3 exhibits minimal circadian variation and reflects the continuous maturation of gonadal tissues.

The purpose of this study is to evaluate INSL3 as an early marker of pubertal activation. By correlating basal INSL3 levels, measured via ELISA, with the outcomes of standard GnRH tests and other clinical parameters, the investigators hope to determine if INSL3 can accurately predict HPG axis activation. Ultimately, validating this biomarker could lead to a simpler, single-sample diagnostic approach, reducing the burden of dynamic stimulation testing in pediatric practice.

Study Type

Observational

Enrollment (Estimated)

100

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

      • Bologna, Italy, 40138
        • Recruiting
        • IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Bologna 40138
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

1 second to 18 years (Child, Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

Pediatric patients of both sexes, aged 0 to 16 years, who are followed for suspected Central Precocious Puberty (CPP) or suspected Delayed Puberty (DP) at the Pediatric Endocrinology Unit of the IRCCS Azienda Ospedaliero-Universitaria of Bologna. These patients must have a clinical indication to undergo a standard GnRH stimulation test as part of their routine diagnostic workup for pubertal evaluation.

Description

Inclusion Criteria:

  • Age between 0 and 16 years at the time of enrollment.
  • Males with suspected Central Precocious Puberty (CPP), defined by a testicular volume ≥4 mL before 9 years of age.
  • Females with suspected CPP, defined by the onset of thelarche before 8 years of age.
  • Males with suspected Delayed Puberty (DP), defined by testicular volume <4 mL by 14 years of age.
  • Females with suspected DP, defined by the absence of thelarche by 13 years of age.
  • Written informed consent for study participation and personal data processing provided by the parents/legal guardians, with the assent of the participating minor.

Exclusion Criteria:

  • Presence of congenital or acquired conditions known to primarily alter pubertal development or gonadal function, regardless of HPG axis physiology (e.g., disorders of sex development, anorchia, previous ovariectomy, uncorrected bilateral cryptorchidism, previous iatrogenic gonadotoxicity).
  • Primary endocrine diseases interfering with hypothalamic-pituitary-gonadal axis regulation (e.g., congenital hypogonadotropic hypogonadism, panhypopituitarism).
  • Use of hormonal therapies or drugs capable of modifying gonadal function or the response to the GnRH test (e.g., exogenous sex steroids, androgens/anabolic steroids).

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: COHORT
  • Time Perspectives: PROSPECTIVE

Cohorts and Interventions

Group / Cohort
Suspected Central Precocious Puberty (CPP)

Pediatric patients (males under 9 years, females under 8 years) with clinical signs of early pubertal onset, undergoing a standard GnRH stimulation test.

Suspected Delayed Puberty (DP)

Pediatric patients (males 14 years and older, females 13 years and older) with absent signs of puberty, undergoing a standard GnRH stimulation test.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Baseline INSL3 Concentration as a Predictor of GnRH Test Outcome
Time Frame: Baseline (prior to GnRH test administration)

Assessment of baseline Insulin-like peptide 3 (INSL3) levels (measured in pg/ml) and their association with the gonadotropin response to the standard GnRH stimulation test (evaluated by peak LH, peak FSH in mU/ml, and LH/FSH ratio) to determine Hypothalamic-Pituitary-Gonadal (HPG) axis activation in patients with suspected precocious or delayed puberty.

Baseline (prior to GnRH test administration)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Diagnostic Accuracy of Combined INSL3 and Clinical Parameters
Time Frame: Baseline

Evaluation of whether integrating baseline INSL3 (pg/ml) with other clinical and laboratory parameters (bone age in years, uterine longitudinal diameter in cm and volume in ml, basal LH/FSH in mU/ml, estradiol in pg/ml, and testosterone in ng/ml) improves the ability to distinguish patients with a positive GnRH test from those with a negative test.

Baseline
Correlation Between INSL3 and Pubertal Development Parameters
Time Frame: Baseline

Assessment of the correlation between baseline INSL3 levels (pg/ml) and key physiological parameters of pubertal development, including bone age, baseline gonadotropins, sex steroids, and, in females, uterine dimensions.

Baseline

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

October 2, 2026

Primary Completion (Estimated)

September 30, 2027

Study Completion (Estimated)

January 1, 2029

Study Registration Dates

First Submitted

September 30, 2026

First Submitted That Met QC Criteria

September 30, 2026

First Posted (Actual)

October 6, 2026

Study Record Updates

Last Update Posted (Actual)

October 6, 2026

Last Update Submitted That Met QC Criteria

September 30, 2026

Last Verified

September 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

  • INSL3GNRH

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

De-identified individual participant data (IPD) underlying the results of this study will be shared upon reasonable request to the Principal Investigator. The shared data will include clinical, auxological, biochemical, and instrumental parameters used for the analyses, provided in a completely anonymous format to protect participant privacy.

IPD Sharing Time Frame

Following the publication of the study results.

IPD Sharing Access Criteria

Data will be shared upon reasonable request submitted to the Principal Investigator.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

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