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AgingPhase 2ABLENCT05706389

Does Alpha-ketoglutarate Supplementation Lower BiologicaL agE in Middle- Aged Adults?

A Phase 2 study testing Ca-AKG in people with Aging, run by National University of Singapore at 1 site in Singapore.

Active, not recruiting

Under way, not looking for participants. Everyone needed has enrolled. The study is still running.

Official record
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Trial summary

Geroscience is an emerging interdisciplinary field of study in gerontological sciences. With emphasis on understanding the mechanistic drivers of aging, it seeks translational approaches that could eventually be applied to improve human healthspan and delay age-associated chronic diseases. Read more about this study

Who is it for?
Ages 40 to 60 yearsHealthy volunteers can take part
Conditions the study is for
Aging
What is being tested?
Ca-AKG
Type of treatment
Pill or oral medicine
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
120 participants
Where
1 siteSingapore
Study dates
24 Feb 2023to 15 Jan 2027
Phase
Phase 2
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 40 to 60 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • participants whose biological age (as measured by blood DNA methylation) is greater than their chronological age

Who cannot join

  • pregnant women
  • more than ONE of the following chronic medical conditions (based on the medical history and during screening), they are NOT eligible to participate in the study:
  • Waist circumference more than or equal to 90 cm for males or more than or equal to 80 cm for females
  • Fasting triglycerides more than or equal to 1.7 mmol/l
  • High-density lipoprotein less than 1.0 mmol/l in men or less than 1.3 mmol/l in women
  • Blood pressure more than or equal to 130/85 mmHg or use of antihypertensive medication
Show all 26Show fewer
  • Fasting glucose more than or equal to 6.0 mmol/l
  • Osteopenia
  • Mild Osteoarthritis not interfering in daily activities
  • Fatty liver
  • Participants will NOT be recruited if they fall in the following categories:
  • Pre-existing, or history of major CVD (coronary artery disease, heart failure, stroke, peripheral vascular disease, pulmonary hypertension), severe/uncontrolled hypertension (under 3 or more than 3 prescribed medications), rheumatic heart disease, congenital heart disease, deep vein thrombosis, pulmonary embolism
  • Type 1 diabetes and Type 2 diabetes under oral metformin or insulin therapy and with diabetic complications such as diabetic retinopathy, diabetic nephropathy
  • Active cancer or treatment of cancer in the last 3 years
  • Chronic obstructive pulmonary disease (COPD), severe asthma (taking daily medications)
  • Pregnant women will not be recruited into this study because of the safety issues associated with X-ray irradiation during DXA scan
  • Potential female participants who plan on pregnancy within the next 9 months of study period
  • Multiple sclerosis and autoimmune/immune deficiency diseases such as Rheumatic arthritis, HIV, Crohn's disease
  • Recent history of sepsis or infection (within 3 months of in-patient hospitalization)
  • Any psychiatric disease or neurodegenerative diseases such as Alzheimer's Disease, Parkinson's Disease, Lewy body dementia, and any eating disorders
  • Any metal implants in the body
  • Hepatitis and Liver cirrhosis (independent of severity)
  • Severe kidney disease (GFR less than 30 ml/min/1.73 m2)
  • Skin disease (on oral or systemic medication for immune system)
  • Subjects receiving any other similar investigational product within 60 days or 5 halflives before the screening, whichever that is longer
  • Any serious medical illness which in the PI's judgment may jeopardize the subject by his or her participation in this study or may hamper his or her ability to perform and complete procedures required in the study

Trial locations and contacts

1 site in 1 country.

Singapore1 site
  • Centre for Healthy Longevity, Alexandra Hospital

    Singapore, 159964

Other trials in Singapore

About this study

Geroscience is an emerging interdisciplinary field of study in gerontological sciences. With emphasis on understanding the mechanistic drivers of aging, it seeks translational approaches that could eventually be applied to improve human healthspan and delay age-associated chronic diseases. Contrary to popular opinion that aging is irreversible, advances in geroscience research have demonstrated that aging is modifiable and inhibiting or activating specific molecular pathways can improve healthspan and extend lifespan in model organisms. Advocates of geroscience take the view that age-related chronic diseases are best treated by slowing the aging process, rather than using the prevailing disease-centric approach of addressing each disease alone. Thus, the concept is that biological aging, rather than chronological aging, is amenable to intervention.

In this regard, geroscientists are at the forefront of longevity medicine in rigorously testing novel supplements, drugs and other prophylactics that can enhance healthspan. Some of these interventions involve repurposing existing drugs such as rapamycin, a well-known immunosuppressant, at different dosing regimens to specifically target biological hallmarks of aging.

This study will investigate the effects of alpha-ketoglutarate (AKG), an endogenous metabolite, on biomarkers of aging in middle-aged residents of Singapore.

Read the detailed description

Recent growing understanding on mechanisms of aging as gradual changes in body systems through several cellular and molecular levels has raised research interests in the biology of aging. There are seven established overlapping processes of aging: oxidative stress, macromolecular damage, epigenetic changes, abnormal metabolism, impaired proteostasis, decline in stem cell functions and inflammation. These overlapping changes over the lifetime affect the onset of age-related diseases and possibly the aging process itself. However, lifestyle and pharmacologic interventions can modify the deterioration of aging pathways. AKG is a generally regarded as safe (GRAS) micronutrient and has shown great potential in extending healthspan. Here, we aim to study the role of AKG in the modulation of aging.

The aim is to evaluate the anti-aging function of AKG and determine whether AKG can modulate biological pathways of aging in middle-aged adults in Singapore. Our hypothesis is that AKG will affect DNA methylation which will be associated with the change in blood biomarkers of aging and change in physiological function. It allows us to study the longitudinal effects of AKG on clinical and biological outcomes.

This is a 6-month double-blinded, placebo-controlled longitudinal interventional study on middle-aged participants to study the effect of AKG on biomarkers of aging, with another 3 months of post-intervention follow-up. The total duration of participation in this study is 9 months.

The rationale for this study design is to study the long-term effect of 1 g AKG in middle-aged adults. Our study design of 6 months of intervention (1 g AKG vs placebo) will allow us to understand the effect of AKG treatment on DNA methylation, and another 3 months of post-intervention follow-up will help us understand if there is any long-term effect of AKG. In order to minimize recruitment bias, our study design is double-blinded.

Conditions
Aging
Being tested
Ca-AKG
Keywords
Aging, Geroscience, Alpha-Ketoglutarate, DNA methylation, Healthspan, epigenetic aging clock

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Ca-AKGDietary supplement

    Eligible participants will be randomised to receive Ca-AKG or Placebo for 6 months.

Study groups in NCT05706389
Study groupRoleWhat they receive
Ca-AKGExperimentalPill format, 500mg/pill, half of daily dose
Receives: Dietary Supplement: Ca-AKG
PlaceboPlacebo comparatorPill format, indistinguishable from active pill
Receives: Dietary Supplement: Ca-AKG

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Change in blood DNA methylation status, years

    DNA methylation aging clock

    Measured: from baseline to end of intervention (6 months)

Secondary outcomes (34)
  1. Complete blood count

    comparison of blood count at baseline and 6 months

    Measured: from baseline to end of intervention (6 months)

  2. Carotid-femoral Pulse Wave Velocity change

    comparison of PWV at baseline and 6 months

    Measured: from baseline to end of intervention (6 months)

  3. Central Blood pressure change

    comparison of Central Blood pressure at baseline and 6 months

    Measured: from baseline to end of intervention (6 months)

  4. Body Mass Index (BMI) change

    comparison of BMI at baseline and 6 months

    Measured: from baseline to end of intervention (6 months)

  5. Brachial Blood pressure change

    comparison of Brachial Blood pressure at baseline and 6 months

    Measured: from baseline to end of intervention (6 months)

  6. Waist/hip ratio change

    comparison of Waist/hip ratio at baseline and 6 months

    Measured: from baseline to end of intervention (6 months)

  7. Bone Mineral Density, g/cm2 change

    comparison of Bone Mineral Density at baseline and 6 months

    Measured: from baseline to end of intervention (6 months)

  8. Fat-free mass, change (kg)

    comparison of fat-free mass at baseline and 6 months

    Measured: from baseline to end of intervention (6 months)

  9. Fat mass, change (kg)

    comparison of fat mass at baseline and 6 months

    Measured: from baseline to end of intervention (6 months)

  10. Handgrip strength change (kg)

    comparison of handgrip strength at baseline and 6 months

    Measured: from baseline to end of intervention (6 months)

  11. 8-RM leg extension change (kg)

    comparison of 8RM leg extension at baseline and 6 months

    Measured: from baseline to end of intervention (6 months)

  12. Cardiopulmonary exercise test (CPET): Change in Volume of Oxygen consumption (V̇O2), L/min

    comparison of VO2 during CPET at baseline and 6 months

    Measured: from baseline to end of intervention (6 months)

  13. Cardiopulmonary exercise test (CPET): Change in Volume of Oxygen consumption per kg body weight (V̇O2/kg), L/min/kg

    comparison of VO2/kg during CPET at baseline and 6 months

    Measured: from baseline to end of intervention (6 months)

  14. Cardiopulmonary exercise test (CPET): change in lactate

    comparison of lactate levels during CPET at baseline and 6 months

    Measured: from baseline to end of intervention (6 months)

  15. Cardiopulmonary exercise test (CPET): change in heart rate

    comparison of heart rate levels during CPET at baseline and 6 months

    Measured: from baseline to end of intervention (6 months)

  16. Cardiopulmonary exercise test (CPET): aerobic and anaerobic threshold change

    comparison of aerobic and anaerobic threshold levels during CPET at baseline and 6 months

    Measured: from baseline to end of intervention (6 months)

  17. Cardiopulmonary exercise test (CPET): excess post-exercise oxygen consumption change

    comparison of excess post-exercise oxygen consumption levels during CPET at baseline and 6 months

    Measured: from baseline to end of intervention (6 months)

  18. Change in Skin autofluorescence, au

    comparison of skin autofluorescence levels at baseline and 6 months

    Measured: from baseline to end of intervention (6 months)

  19. Change in Quality-of-Life questionnaires (SF-36 questionnaires)

    comparison of Quality-of-life at baseline and 6 months

    Measured: from baseline to end of intervention (6 months)

  20. Change in Quality-of-Life questionnaires (EuroQoL-5D-5L)

    comparison of Quality-of-life at baseline and 6 months

    Measured: from baseline to end of intervention (6 months)

  21. Change in Sleep (modified Pittsburgh sleep quality Questionnaire )

    comparison of sleep at baseline and 6 months

    Measured: from baseline to end of intervention (6 months)

  22. Change in Sleep (Satisfaction, Alertness, Timing, Efficiency and Duration (SATED) Questionnaire )

    comparison of sleep at baseline and 6 months

    Measured: from baseline to end of intervention (6 months)

  23. Change in Global preferences survey (GPS)

    comparison of global preferences (GPS) at baseline and 6 months

    Measured: from baseline to end of intervention (6 months)

  24. AKG, glutamate, glutamine concentrations in serum

    Metabolites in serum change

    Measured: from baseline to end of intervention (6 months)

  25. Change in Immune parameters (Complete Blood Count)

    Immune parameters change

    Measured: from baseline to end of intervention (6 months)

  26. Change in Immune parameters (inflammatory parameters in serum, mg/dL)

    Immune parameters change

    Measured: from baseline to end of intervention (6 months)

  27. Change in Clinical Blood parameters: Renal function, mg/dL

    Clinical Blood parameters change

    Measured: from baseline to end of intervention (6 months)

  28. Change in Clinical Blood parameters: Lipid profile test, mmol/L

    Clinical Blood parameters change

    Measured: from baseline to end of intervention (6 months)

  29. Change in Clinical Blood parameters: Glucose, mg/dL

    Clinical Blood parameters change

    Measured: from baseline to end of intervention (6 months)

  30. Change in Clinical Blood parameters: insulin, mg/dL

    Clinical Blood parameters change

    Measured: from baseline to end of intervention (6 months)

  31. Change in Clinical Blood parameters: HbA1C, mmol/mol

    Clinical Blood parameters change

    Measured: from baseline to end of intervention (6 months)

  32. Change in Clinical Blood parameters: Metabolites, mmol/l

    Clinical Blood parameters change

    Measured: from baseline to end of intervention (6 months)

  33. Change in Cognitive function test by Montreal Cognitive Assessment (MoCA)

    Cognitive function change

    Measured: from baseline to end of intervention (6 months)

  34. Change in saliva DNA methylation status, years

    DNA methylation aging clock

    Measured: from baseline to end of intervention (6 months)

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted31 Jan 2023
  2. Study start24 Feb 2023
  3. Primary completion15 Aug 2025
  4. Study completion15 Jan 2027 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 2
Primary purpose
Prevention
Allocation
Randomised
Intervention model
Parallel groups
Model description
Double-blinded, placebo-controlled longitudinal interventional study on middle-aged participants
Masking
Quadruple blind
Who is masked
Participant, Care provider, Investigator, Outcomes assessor
Enrolment
120 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05706389
Sponsor's protocol ID
NUS-IRB-2021-946
Acronym
ABLE
Status last verified
May 2026
First submitted
25 Dec 2022
Last updated
26 May 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Publications

  • Lu JK, Wang W, Chew YE, Guan L, Kennedy BK, Maier AB. Optimizing accelerometer implementation in a gerotherapeutic trial: Feasibility, adherence, and operational insights of ABLE. PLOS Digit Health. 2026 Sep 25;5(9):e0001691. doi: 10.1371/journal.pdig.0001691. eCollection 2026 Sep.

    PubMed 42789532

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing Ca-AKG in people with Aging, run by National University of Singapore at 1 site in Singapore.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 1 inclusion and 26 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: under way, not looking for participants, as of the sponsor's last update on 26 May 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Singapore. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Change in blood DNA methylation status, years (time frame: from baseline to end of intervention (6 months)). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05706389, which also lists 1 linked publication.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 26 May 2026.

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