Autophagy-Enhancers to Reduce Sleep Disturbances (SpSleep)

University Medicine Greifswald

Status: Enrolling

Conditions: Mild Cognitive Impairment Due to Alzheimer's Disease

Treatments: Dietary Supplement: Dietary Placebo; Dietary Supplement: Spermidine Supplementation

Study type: Interventional

Funder types: Other

Identifiers

NCT07383311

Autophagy and Sleep

508402643 (Other Grant/Funding Number)

Details and patient eligibility

About

This clinical trial investigates the effects of spermidine supplementation on sleep quality and memory function in older adults with Mild Cognitive Impairment (MCI), a condition associated with an increased risk of developing dementia, particularly in patients with MCI due to Alzheimer's disease. Impaired sleep has been identified as a modifiable factor contributing to cognitive decline, and interventions targeting sleep architecture could offer therapeutic potential to prevent or slow down this decline.

Spermidine is a naturally occurring polyamine found in foods such as wheat germ and soybeans. It induces autophagy, a cellular degradation and recycling process essential for neuronal maintenance and function. In animal studies, spermidine has been shown to improve memory performance, reduce neuroinflammation, and support mitochondrial health. Preliminary findings from human trials in individuals with subjective cognitive decline or MCI suggest potential cognitive benefits of spermidine, but results are not unequivocal, and the impact on sleep has not been systematically evaluated.

In this randomized, double-blind, placebo-controlled trial, 76 participants aged 55 to 70 years with MCI will receive either spermidine (6 mg/day) or a placebo for 12 weeks. Sleep will be evaluated using overnight EEG in a controlled laboratory setting, focusing on measures such as slow-wave sleep and sleep spindle activity. Memory performance will be assessed before and after the intervention using standardized neuropsychological testing. Numerical skills will be tested at baseline only to compare MCI patients with healthy controls.

Blood samples will be collected to quantify metabolic indicators, neurodegeneration-related biomarkers, and autophagy-associated proteins. A control group of 38 cognitively healthy individuals will undergo comparable sleep and cognitive assessments without receiving any supplementation.

The primary objective of the study is to characterize the impact of spermidine on sleep-dependent memory consolidation and to identify associated biological changes relevant to aging and neurodegeneration. The results may inform the development of non-pharmacological strategies aimed at preserving cognitive function in individuals at risk for dementia.

Full description

Mild Cognitive Impairment (MCI) is a clinical condition characterized by measurable cognitive decline that exceeds age-related norms but does not meet criteria for dementia, often due to Alzheimer's Disease (AD). It is associated with an increased likelihood of progressing to dementia due to AD or other forms of dementia. Disruption of sleep architecture is increasingly implicated in the pathophysiology of neurodegenerative disorders, and early interventions targeting sleep-related mechanisms could help delay further cognitive decline. This clinical trial evaluates the effects of spermidine supplementation on sleep quality and sleep-dependent memory consolidation in older adults diagnosed with MCI.

Following an adaptation night and an initial baseline sleep assessment with overnight electroencephalography (EEG), participants will be randomly assigned to either the spermidine or placebo group. The intervention consists of a daily oral dose of 6 mg spermidine (administered as three 2 mg sachets), continued over a 12-week period. The trial employs a randomized, double-blind, placebo-controlled design. Placebo sachets, identical in appearance and taste, contain only microcrystalline cellulose. After the 12-week supplementation period, participants will return for a second overnight EEG assessment.

A healthy control group (n=38), matched for age and sex, will undergo comparable baseline assessments but will not receive any intervention. These data will provide normative reference values for sleep and cognitive parameters.

The primary objective of the study is to assess the impact of spermidine on sleep architecture, measured via overnight polysomnography, with a specific focus on slow-wave sleep and sleep spindle activity, EEG markers associated with sleep-dependent memory consolidation and known to decline with age and neurodegeneration. Secondary outcomes include changes in memory consolidation (assessed using a battery of cognitive tasks that target declarative, procedural, and visuospatial memory domains), as well as numerical skills (tested via e.g., digit-letter-decision task, Berlin Numeracy Test). Testing occurs before and after each EEG night to evaluate overnight consolidation effects. All participants will wear actigraphs prior to both EEG nights to monitor sleep-wake cycles and physical activity.

Additional biological endpoints will examine changes in circulating neuropeptides, insulin-glucose homeostasis, and autophagy-related biomarkers. Blood samples are collected at each EEG session and two weeks after the start of supplementation. Physiological assessments include oral glucose tolerance tests, measurements of inflammatory markers (e.g., interleukin (IL)-6, tumor necrosis factor (TNF-α), neuroprotective factors (e.g., Neuropeptide Y, eukaryotic translation initiation factor 5A (eIF5A) hypusination), and metabolic indicators (e.g., fasting insulin, glucose, and lipid profiles).

Participants will undergo structural brain imaging using a 3-Tesla MRI scanner to exclude individuals with comorbid neurological conditions (e.g., prior stroke, other neurodegenerative diseases) and to assess brain morphology. Eligibility is determined through standardized pre-screening procedures, including clinical interviews and neuropsychological assessments.

The study includes 76 participants with MCI, aged 55-70 years, randomly allocated to either the spermidine or placebo group (n=38 per group). The sample size provides adequate statistical power to detect medium-to-large effect sizes, based on previous pilot findings and anticipated attrition rates.

This study aims to investigate the effects of spermidine supplementation on neurophysiological and cognitive outcomes in individuals with early-stage cognitive decline. The results are expected to contribute to the growing body of evidence evaluating spermidine as a safe, nutrition-based strategy for maintaining brain health and cognitive function in the context of aging.

Enrollment: 76 estimated patients

Sex: All

Ages: 55 to 70 years old

Volunteers: Accepts Healthy Volunteers

Inclusion and exclusion criteria

Inclusion Criteria (MCI patients):

• Men and women

• Written consent to participate in the study

• German at native speaker level

• Age between 55 and 70 years

• Mild cognitive impairment (MCI) operationalized as:

  1. A change in cognitive abilities reported by the patient, relatives or clinic staff (i.e. historical or observed evidence of deterioration over time)
  2. Objective evidence of memory impairment (at least 1.0 Standard Deviation (SD) below the normal range on the Wechsler Logical Memory Scale (WMS-LM)); other cognitive domains may also be affected (i.e. amnestic MCI and amnestic + MCI)
  3. Preservation of independence of functional abilities
  4. No dementia

Exclusion Criteria (MCI patients):

• Patients who are unable to give informed consent
• Polyamine intake via dietary supplements and/or participation in corresponding intervention studies
• Dementia according to the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV)
• Any condition that impairs clinical or neuropsychological examination procedures
• Diabetes mellitus
• Polycystic ovary syndrome
• Signs of epilepsy, focal brain lesion or head injury with loss of consciousness or immediate post-injury confusion
• Previous stroke
• Severe untreated medical problems or unstable medical condition
• Current major depressive episode
• Psychotic disorder
• Bipolar disorder
• Current or previous substance abuse
• Other neurodegenerative disease, e.g. Parkinson's disease
• Vascular dementia
• Alcohol abuse
• Participation in an interventional study in the last 3 months and during the entire study period
• Sleep disorders
• Taking medication that primarily affects the central nervous system (e.g. antipsychotics, antidepressants, benzodiazepines or any type of over-the-counter sleep-inducing medication such as valerian; anti-dementia medication)
• Known intolerances or allergies to wheat germ, gluten or histamine

Inclusion criteria (healthy controls):

• Men and women
• Written consent to participate in the study
• German at native speaker level
• Age between 55 and 70 years
• Subjective cognitive disorders are denied

Exclusion criteria (healthy controls):

• Subjects who are not able to give informed consent
• Polyamine intake via dietary supplements and/or participation in corresponding intervention studies
• Dementia according to the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV)
• Mild cognitive impairment (MCI), defined as described above in the patient inclusion criteria
• Any condition that interferes with clinical or neuropsychological examination procedures
• Diabetes mellitus
• Polycystic ovary syndrome
• Signs of epilepsy, focal brain lesion or head injury with loss of consciousness or immediate post-injury confusion
• Previous stroke
• Severe untreated medical problems or unstable medical condition
• Current major depressive episode
• Psychotic disorder
• Bipolar disorder
• Current or past substance abuse
• Other neurodegenerative disease, e.g. Parkinson's disease
• Vascular dementia
• Alcohol abuse
• Participation in an interventional study in the last 3 months and during the entire study period
• Sleep disorders
• Taking medication that primarily affects the central nervous system (e.g. antipsychotics, antidepressants, benzodiazepines or any type of over-the-counter sleep-inducing medication such as valerian; anti-dementia medication)

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

---

76 participants in 3 patient groups, including a placebo group

Healthy elderly controls

No Intervention group

Description:

baseline comparison, healthy controls are not part of the intervention

Dietary Placebo

Placebo Comparator group

Treatment:

Dietary Supplement: Dietary Placebo

Dietary Supplement

Experimental group

Treatment:

Dietary Supplement: Spermidine Supplementation