Skip to main content
OpenTrials
Completed

NCT Number: NCT07027943

Evaluation Of The Diamine Oxidase Supplementation Effect In Patients With Insomnia Symptoms

Considering the high prevalence of DAO enzyme deficiency in patients referring insomnia symptoms, it would be plausible that the appearance of insomnia symptoms were explained by the DAO enzyme deficiency.

One of the strategies to revert DAO enzyme deficiency would be to supplement patients with DAO enzyme, helping at recovering the normal DAO levels. Therefore, the objective of the present study is to evaluate the effect of DAO enzyme supplementation on the insomnia symptoms characteristics in patients with insomnia symptoms and genetic DAO deficiency as expected from bearing at least one of the 4 above-mentioned SNPs of the AOC1 gene.

Completed

Looking for future studies?

Notify Me

Key information

Conditions

Insomnia Dyssomnias Insomnia Type; Sleep Disorder Mental Disorders Nervous System Diseases Neurologic Manifestations Pathological Conditions, Signs and Symptoms Signs and Symptoms Sleep Disorders, Intrinsic Sleep Initiation and Maintenance Disorders Sleep Wake Disorders

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

AdSalutem Sleep Institute

Barcelona, 08008, Spain

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Older than 18 years
  • With the ability to understand and sign informed consent reviewed and approved by the Grupo Hospitalario Quironsalud-Catalunya.
  • That refer one or more symptoms of insomnia, these being: Difficulty initiating sleep, Difficulty maintaining sleep, Waking up early with inability to go back to sleep.
  • Who are carriers, either heterozygous or homozygous, of at least one of the following 4 SNPs associated with a reduction in the enzymatic activity of DAO or a decreased transcriptional activity of it: c.47C>T (rs10156191), c.995C>T (rs1049742), c.1990C>G (rs1049793), c.-691G>T (rs2052129).
  • With the ability to attend the foreseen face-to-face and telephonic study visits.
  • With the ability to intake the product under study
  • Explicit agreement on study participation by reading, understanding, and signing the informed consent reviewed and approved by the Grupo Hospitalario Quironsalud-Catalunya

Exclusion criteria

  • Insomnia symptoms referred by patients that might be explained by other co-morbid sleep disorders, e.g., narcolepsy, circadian rhythm disturbances, parasomnia, etc.
  • Taking DAO supplementation less than 1 month prior to the start of the study.
  • Following a diet low in histamine less than 1 month prior to the start of the study.
  • Volunteers with allergies to some of the ingredients of the product under study.

Treatment and study plan

DAO supplement

Dietary Supplement

Gastro-resistant DAO tablets of porcine kidney protein extract. Posology: 3 tablets per day (total 12.6mg of DAO extract/day).

Placebo

Dietary Supplement

Tablets containing microcrystalline cellulose and hydroxypropyl cellulose, with the same shape, size, and color as the DAO-containing tablets. Posology: 3 tablets per day.

Primary outcomes

  1. Number (absolute and percentage) of patients who improve their symptoms of insomnia and daytime repercussions by at least one point in the Insomnia Severity Index (ISI) scale

    Time frame: Visit day 0, day 7, day 14, day 21 and day 28.

    Number (absolute and percentage) of patients who improve their symptoms of insomnia and daytime repercussions by at least one point in the Insomnia Severity Index (ISI) scale after one month of DAO supplementation, compared to the placebo group. Score goes from 0 to 28. A higher score indicates a worse outcome (severity of insomnia).

Secondary outcomes

  1. Number (absolute and percentage) of patients who improve their symptoms of insomnia and daytime repercussions by at least one point in the Insomnia Severity Index (ISI) scale

    Time frame: Visit day 0, day 7, day 14, day 21 and day 28.

    Number (absolute and percentage) of patients who improve their symptoms of insomnia and daytime repercussions by at least one point in the Insomnia Severity Index (ISI) scale after one month of DAO supplementation, compared to the placebo group, stratified by the SNP variants of AOC1 gene. Score goes from 0 to 28. A higher score indicates a worse outcome (severity of insomnia).

  2. Number (absolute and percentage) of patients who improve their symptoms of insomnia and daytime repercussions by at least one point in the Insomnia Severity Index (ISI) scale

    Time frame: Visit day 0, day 7, day 14, day 21 and day 28.

    Number (absolute and percentage) of patients who improve their symptoms of insomnia and daytime repercussions by at least one point in the Insomnia Severity Index (ISI) scale after one month of DAO supplementation, compared to the placebo group, stratified by the use of insomnia pharmacological treatment (benzodiazepines, melatonin, others, or no pharmacological treatment). Score goes from 0 to 28. A higher score indicates a worse outcome (severity of insomnia).

  3. Number (absolute and percentage) of patients who improve their symptoms of insomnia and daytime repercussions in the Insomnia Severity Index (ISI) scale

    Time frame: Visit day 0, day 7, day 14, day 21 and day 28.

    Number (absolute and percentage) of patients who improve their symptoms of insomnia and daytime repercussions in the Insomnia Severity Index (ISI) scale after one month of DAO supplementation, compared to the placebo group. Score goes from 0 to 28. A higher score indicates a worse outcome (severity of insomnia).

  4. Number (absolute and percentage) of patients who improve their symptoms of insomnia and daytime repercussions in the Insomnia Severity Index (ISI) scale

    Time frame: Visit day 0, day 7, day 14, day 21 and day 28.

    Number (absolute and percentage) of patients who improve their symptoms of insomnia and daytime repercussions in the Insomnia Severity Index (ISI) scale after one month of DAO supplementation, compared to the placebo group, stratified by the SNP variants of AOC1 gene. Score goes from 0 to 28. A higher score indicates a worse outcome (severity of insomnia).

  5. Number (absolute and percentage) of patients who improve their symptoms of insomnia and daytime repercussions by at least one point in the Pittsburgh Sleep Quality Index (PSQI) scale

    Time frame: Visit day 0 and day 28.

    Number (absolute and percentage) of patients who improve their symptoms of insomnia and daytime repercussions by at least one point in the Pittsburgh Sleep Quality Index (PSQI) scale after one month of DAO supplementation, compared to the placebo group. Score goes from 0 to 21. A higher score indicates a worse outcome in sleep quality.

  6. Number (absolute and percentage) of patients who improve their symptoms of insomnia and daytime repercussions by at least one point in the Pittsburgh Sleep Quality Index (PSQI) scale

    Time frame: Visit day 0 and day 28.

    Number (absolute and percentage) of patients who improve their symptoms of insomnia and daytime repercussions by at least one point in the Pittsburgh Sleep Quality Index (PSQI) scale after one month of DAO supplementation, compared to the placebo group, stratified by the SNP variants of AOC1 gene. Score goes from 0 to 21. A higher score indicates a worse outcome in sleep quality.

  7. Number (absolute and percentage) of patients who improve their symptoms of insomnia and daytime repercussions by at least one point in the Pittsburgh Sleep Quality Index (PSQI) scale

    Time frame: Visit day 0 and day 28.

    Number (absolute and percentage) of patients who improve their symptoms of insomnia and daytime repercussions by at least one point in the Pittsburgh Sleep Quality Index (PSQI) scale after one month of DAO supplementation, compared to the placebo group, stratified by the use of insomnia pharmacological treatment (benzodiazepines, melatonin, others, or no pharmacological treatment). Score goes from 0 to 21. A higher score indicates a worse outcome in sleep quality.

  8. Number (absolute and percentage) of patients who improve their symptoms of insomnia and daytime repercussions in the Pittsburgh Sleep Quality Index (PSQI) scale

    Time frame: Visit day 0 and day 28.

    Number (absolute and percentage) of patients who improve their symptoms of insomnia and daytime repercussions in the Pittsburgh Sleep Quality Index (PSQI) scale after one month of DAO supplementation, compared to the placebo group. Score goes from 0 to 21. A higher score indicates a worse outcome in sleep quality.

  9. Number (absolute and percentage) of patients who improve their symptoms of insomnia and daytime repercussions in the Pittsburgh Sleep Quality Index (PSQI) scale

    Time frame: Visit day 0 and day 28.

    Number (absolute and percentage) of patients who improve their symptoms of insomnia and daytime repercussions in the Pittsburgh Sleep Quality Index (PSQI) scale after one month of DAO supplementation, compared to the placebo group, stratified by the SNP variants of AOC1 gene. Score goes from 0 to 21. A higher score indicates a worse outcome in sleep quality.

  10. Number (absolute and percentage) of patients who reduce at least one point on Component 2 (Sleep latency) of the Pittsburgh Sleep Quality Index (PSQI) scale

    Time frame: Visit day 0 and day 28.

    Number (absolute and percentage) of patients who reduce at least one point on Component 2 (Sleep latency) of the Pittsburgh Sleep Quality Index (PSQI) scale, after one month of DAO supplementation, compared to the placebo group. Score goes from 0 to 21. A higher score indicates a worse outcome in sleep quality.

  11. Number (absolute and percentage) of patients who reduce at least one point on Component 5 (Sleep disturbance) of the Pittsburgh Sleep Quality Index (PSQI) scale

    Time frame: Visit day 0 and day 28.

    Number (absolute and percentage) of patients who reduce at least one point on Component 5 (Sleep disturbance) of the Pittsburgh Sleep Quality Index (PSQI) scale, after one month of DAO supplementation, compared to the placebo group. Score goes from 0 to 21. A higher score indicates a worse outcome in sleep quality.

  12. Number (absolute and percentage) of patients who reduce at least one point on Component 7 (Daytime dysfunction) of the Pittsburgh Sleep Quality Index (PSQI) scale

    Time frame: Visit day 0 and day 28.

    Number (absolute and percentage) of patients who reduce at least one point on Component 7 (Daytime dysfunction) of the Pittsburgh Sleep Quality Index (PSQI) scale, after one month of DAO supplementation, compared to the placebo group. Score goes from 0 to 21. A higher score indicates a worse outcome in sleep quality.

  13. Serum DAO activity levels

    Time frame: Visit day 0 and day 28.

    Mean increase of serum DAO activity levels after one month of DAO supplementation, compared to the placebo group.

  14. Number (absolute and percentage) of patients who increase their serum DAO activity levels

    Time frame: Visit day 0 and day 28.

    Number (absolute and percentage) of patients who increase their serum DAO activity levels after one month of DAO supplementation, compared to the placebo group

  15. Mean DAO baseline activity levels

    Time frame: Visit day 0 and day 28.

    Mean DAO baseline activity levels stratified by the SNP variants of AOC1 gene.

  16. Mean increase in DAO activity levels

    Time frame: Visit day 0 and day 28.

    Mean increase in DAO activity levels, after one month of DAO supplementation, compared to the placebo group, stratified by the SNP variants of AOC1 gene.

  17. Number (absolute and percentage) of patients who improve their symptoms associated with histamine intolerance due to DAO deficiency

    Time frame: Visit day 0 and day 28.

    Number (absolute and percentage) of patients who improve their symptoms associated with histamine intolerance due to DAO deficiency, after one month of DAO supplementation, compared to the placebo group.

  18. Number (absolute and percentage) of patients who refer improvement in their daytime repercussions of insomnia

    Time frame: Visit day 0, day 7, day 14, day 21 and day 28.

    Number (absolute and percentage) of patients who refer improvement in their daytime repercussions of insomnia (such as drowsiness, fatigue, cognitive deficit, lack of concentration, lack of attention or memory, mood swings, and/or headaches) after one month of DAO supplementation, compared to the placebo group.

  19. Number (absolute and percentage) of patients in the once-a day groups who improve their symptoms of insomnia and daytime repercussions by at least one point in the Insomnia Severity Index (ISI) scale

    Time frame: Visit day 0, day 7, day 14, day 21 and day 28.

    Number (absolute and percentage) of patients in the once-a day groups who improve their symptoms of insomnia and daytime repercussions by at least one point in the ISI scale after one month of DAO supplementation compared to placebo. Score goes from 0 to 28. A higher score indicates a worse outcome (severity of insomnia).

  20. Percentage of doses taken of DAO supplementation

    Time frame: Visit day 0 and day 28.

    Percentage of doses taken of DAO supplementation over one month period (counting leftover medication and with patient interview) in the once-a-day groups compared to placebo.

  21. Number (absolute and percentage) of patients in the three times per day groups who improve their symptoms of insomnia and daytime repercussions by at least one point in the Insomnia Severity Index (ISI) scale

    Time frame: Visit day 0, day 7, day 14, day 21 and day 28.

    Number (absolute and percentage) of patients in the three times per day groups who improve their symptoms of insomnia and daytime repercussions by at least one point in the Insomnia Severity Index (ISI) scale after one month of DAO supplementation compared to placebo. Score goes from 0 to 28. A higher score indicates a worse outcome (severity of insomnia).

  22. Percentage of doses taken of DAO supplementation

    Time frame: Visit day 0 and day 28.

    Percentage of doses taken of DAO supplementation over one month period (counting leftover medication and with patient interview) in the three times per day groups compared to placebo

  23. Number (absolute and percentage) of patients who improve their symptoms of insomnia and daytime repercussions by at least one point in the Insomnia Severity Index (ISI) scale

    Time frame: Visit day 0, day 7, day 14, day 21 and day 28.

    Number (absolute and percentage) of patients who improve their symptoms of insomnia and daytime repercussions by at least one point in the Insomnia Severity Index (ISI) scale after one month of DAO supplementation in the once-a-day group compared to the three times per day group. Score goes from 0 to 28. A higher score indicates a worse outcome (severity of insomnia).

  24. Percentage of doses taken of DAO supplementation

    Time frame: Visit day 0 and day 28.

    Percentage of doses taken of DAO supplementation over one month period (counting leftover medication and with patient interview) in the once-a-day groups compared to three times per day.

  25. Percentage of compliant patients

    Time frame: Visit day 0 and day 28.

    Percentage of compliant patients (compliance percentage > 80%) over one month period (counting leftover medication and with patient interview) in the once-a-day groups compared to placebo.

  26. Percentage of compliant patients

    Time frame: Visit day 0 and day 28.

    Percentage of compliant patients (compliance percentage > 80%) over one month period (counting leftover medication and with patient interview) in the three times per day groups compared to placebo.

  27. Percentage of doses taken of DAO supplementation

    Time frame: Visit day 0 and day 28.

    Percentage of doses taken of DAO supplementation over one month period (counting leftover medication and with patient interview) in the once-a-day group compared with the three times per day group.

  28. Percentage of compliant patients

    Time frame: Visit day 0 and day 28.

    Percentage of compliant patients (compliance percentage > 80%) over one month period (counting leftover medication and with patient interview) in the once-a-day group compared with the three times per day group.

  29. Report of adverse events

    Time frame: Visit day 0, day 7, day 14, day 21 and day 28.

    Report of adverse events after one month of DAO supplementation, compared to the placebo group.

Sponsors and collaborators

Lead sponsor

AB Biotek

Industry

Collaborators

  • AdSalutem Sleep Institute

Registry information

Acronym: DAO-SLEEP-2023

Important dates

Study start
2024
Primary completion
2024
Study completion
2024
First posted
Jun 19, 2025
Registry last updated
Jun 19, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.