Analysis of Peripheral Serotonin Levels in a Control Cohort (ASPECT)

The goal of this observational study is to measure serotonin levels in in a control cohort.

The main question aims to determine the mean serum serotonin level in a cohort of adult controls, based on age and sex.

This will allow for the establishment of reference values. We will also measure the different metabolites of tryptophan. These measurements will be performed on residual blood samples in the laboratory, after blood collection carried out as part of routine care. Thus, patients will not need to undergo an additional blood draw.

Study Overview

• Status: Completed
• Conditions: No Condition : to Establish Reference Serum Serotonin Levels in a Control Cohort
• Intervention / Treatment: Other: Dosage of serotonin and tryptophan metabolites levels in serum

Detailed Description

Serotonin (5-HT or 5-hydroxytryptamine) is a monoamine primarily recognized for its role as a neurotransmitter in the central nervous system (CNS). It is synthesized from tryptophan, which is also essential for the production of metabolites in the kynurenine and indole families.

However, serotonin's functions extend beyond the CNS: various peripheral tissues have the capacity to produce and/or utilize serotonin locally, forming systems referred to as "micro-serotonergic." Among serotonin's peripheral roles, it has been demonstrated to positively influence erythropoiesis and red blood cell survival, iron metabolism, skin pigmentation, as well as placental and embryonic development during pregnancy.

In humans, there is no established standard for blood serotonin levels. It is known that, aside from major events, an individual's serotonin levels remain stable throughout life, but it is likely that blood serotonin levels depend on age and sex.

We aim to establish a cohort of adult control patients, for whom we will measure serum serotonin and the different metabolites of tryptophan, to analyze whether serotonin varies according to sex and age, and to determine its average serum levels.

Preliminary data from the laboratory suggest a role for serotonin in iron metabolism. Therefore, as a secondary objective, we also intend to perform an iron status assessment in control patients to analyze whether there are variations in iron parameters based on serotonin levels.

This cohort could also serve as a comparison point for future studies of serum serotonin levels in pathological conditions or during pregnancy.

• Study Type: Observational
• Enrollment (Actual): 100

Contacts and Locations

Study Locations

• France
  • France
    • Corbeil-Essonnes, France, France, 91110
      • Centre Hospitalier Sud Francilien

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

The study population is a control cohort. We will include adult patients aged 18 years or older who have undergone a blood draw at CHSF during the recruitment period. Eligible participants must have hemoglobin, white blood cell, and platelet counts within the laboratory's normal ranges, and a C-reactive protein (CRP) level below 30 mg/L.

Description

Inclusion Criteria:

• Adult patients aged ≥ 18 years
• Who have undergone a blood draw at CHSF during the recruitment period
• With hemoglobin, white blood cell, and platelet counts within the laboratory's normal ranges
• With a C-reactive protein (CRP) level < 30 mg/L

Exclusion Criteria:

• Patients informed about the study who decline participation
• Patients with a current diagnosis or history of psychiatric disorders
• Patients on antidepressants or narcotics at the time of sampling

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
control cohort; Adult patients aged ≥ 18 years; Who have undergone a blood draw at CHSF during the recruitment period; With hemoglobin, white blood cell, and platelet counts within the laboratory's normal ranges; With a C-reactive protein (CRP) level < 30 mg/L	Other: Dosage of serotonin and tryptophan metabolites levels in serum; These measurements will be performed on residual blood samples in the laboratory, after blood collection carried out as part of routine care. Patients will not need to undergo an additional blood draw.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Serotonin	Measurement of serotonin levels in serum (HPLC: high performance liquid chromatography)	at day 0

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Tryptophan metabolites	Measurement of tryptophan metabolites levels in serum (HPLC: high performance liquid chromatography)	at day 0

Collaborators and Investigators

• Sponsor: Centre Hospitalier Sud Francilien
• Investigators: Principal Investigator: Guillemette FOUQUET, MD, Centre Hospitalier Sud Francilien

Study record dates

Study Major Dates

• Study Start (Actual): June 23, 2025
• Primary Completion (Actual): November 16, 2025
• Study Completion (Actual): November 16, 2025

Study Registration Dates

• First Submitted: March 28, 2025
• First Submitted That Met QC Criteria: March 28, 2025
• First Posted (Actual): April 4, 2025

Study Record Updates

• Last Update Posted (Actual): December 30, 2025
• Last Update Submitted That Met QC Criteria: December 22, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: age; iron status; sex; tryptophan; serotonin (5-HT); control cohort
• Additional Relevant MeSH Terms: Behavior; Sexual Behavior; Coitus; Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Neurotransmitter Agents; Psychotropic Drugs; Antidepressive Agents; Serotonin Agents; Antidepressive Agents, Second-Generation; Serotonin Receptor Agonists; Tryptophan; Serotonin
• Other Study ID Numbers: 2024/0033

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No