The Impact of Excessive Dietary Sodium on Brain Health

Study Overview
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Brief Summary
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Sporadic cerebral small vessel disease (CSVD) is not only the most common subtype of vascular dementia, in recent multi-center study showed that sporadic CSVD harbors in a third of Alzheimer's disease (AD) patients in 9 Asian regions. The CSVD increases the severity of cognitive impairment in these patients and has an etiological contribution to the development of AD. Studies demonstrated that CSVD is more prevalent in Chinese than in Australians and this association was independent of traditional vascular risk factors (e.g. hypertension). Other factors such as lifestyle, environmental or genetic factors may explain this difference. Although hypertension is an important cause for CSVD, it only accounts for a small proportion of the variance in CSVD. Irrespective of the cause, it is currently believed that endothelial dysfunction of CSVD is the key pathophysiological mechanism of CSVD. Having an effective treatment of CSVD will have an enormous impact on the prevention of dementia. Excessive dietary sodium is an established risk factor for cardiovascular diseases, including stroke. It is traditionally linked to its effects in raising blood pressure. The Department of Health advocated reducing salt intake for the prevention of hypertension, coronary heart disease, and stroke. However, recent epidemiological studies suggest that it may have a direct effect on cardiovascular diseases independent of blood pressure. A recent animal study showed that excessive dietary sodium-induced cerebral endothelial dysfunction, resulting in cognitive impairment. Interestingly, endothelial dysfunction was related to an adaptive immune response in the gut. A clinical study conducted in the United Kingdom suggested excessive dietary sodium intake may promote CSVD A clinical study conducted in the United Kingdom suggested excessive dietary sodium intake may promote CSVD by increasing WMH volume in the brain, independent of its effects on blood pressure. Notably, a few animal studies showed that the association between high dietary sodium and worse cognitive function in the absence of blood pressure changes. This pinpoints the important role of dietary sodium as an independent contributor to brain health and cognition. This study aims to assess the association between dietary sodium, neuroimaging measures, and cognition in cerebral small vessel disease and controls during the 18-month follow-up.

Detailed Description
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This study hypothesis that high dietary sodium is associated with CSVD-related neuroimaging measures such as reduced white matter hyperintensities, total brain volume, and white matter structural integrity. The second hypothesis is that high dietary sodium is associated with worse cognitive function. These associations may be more prominent in the CSVD group compared to the control group and is independent of blood pressure. Subjects with severe CSVD (n =110) and healthy controls (n =110) will be recruited. 2 trials of 24 hour urine will be collected at baseline visit and 2 trials of 24 hour urine will be collected at 18 months. Clinical assessment (e.g. mood, cognition, physical activities, gait etc.) will be assessed at baseline and 18 months. 2 trials of Brain MRI will be conducted at baseline and 18 month visit

Official Title
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The Impact of Excessive Dietary Sodium on Brain Health: Examining a Common But Neglected Risk Factor

Conditions
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Cerebral Small Vessel Disease

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Chinese ethnicity, age between 55 and 80-year-old, and a primary language of Cantonese. Extra inclusion criteria for CSVD group: Age-Related White Matter Change (ARWMC) Scale of 2 or early 3 in FLAIR MRI; Modified Functional Ambulation Classification 5 or above; Montreal Cognitive Assessment (MoCA) score < 25; Exclusion Criteria: Hypernatremia (Na >146mmol/L) or hyponatremia (Na <134 mmol/L) from screening blood test; With sodium supplement; Renal failure (stage 4 & 5) with glomerular filtration rate < 29; performed cardiac surgery or neurosurgery, with cardiac failure; Had major psychiatric diseases Contraindications for MRI. Dementia or MoCA score lower than 2nd percentile of the age and education adjusted cutoff ; Cerebral white matter changes unrelated to neurodegenerative, e.g. CADASIL, X-linked adrenoleukodystrophy, metabolic diseases, multiple sclerosis, etc.| Contraindication to proposed imaging, e.g. chronic kidney disease (KDNIGO) stage 4 or above, acute kidney injury, hypersensitivity to gadolinium-based contrast, non-MRI conditional implants or prosthesis Medical condition that would not allow the patient to adhere to the protocol or complete the study.; Patient with established neurodegenerative disorders (e.g. Parkinson's Disease, Alzheimer's Disease, etc.); Pregnancy.

Ages Eligible for Study
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Minimum Age: 55 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change of level of urinary sodium | 24 hours of urine will be collected to measure the level of sodium The higher the sodium level the worse the outcome | Baseline and 18 month | 
| Change of Gait | Gait velocity will be assessed using the 8-meter walking time. Time for walking 8-m will be measured by a stopwatch. The faster of two trials will be used in the analysis The faster of the walking time the better outcome. | Baseline and 18 month | 
| Change of balance | Single leg stance time will be measured by asking participants, with their hands on their hips, to balance as long as possible on one leg with an upper limit of 30 seconds. Two trials for each leg will be performed. The best time of the four trials will be used for analysis. The longer the time duration the better outcome. | Baseline and 18 month | 
| Change of Hong Kong MOntreal Cognitive Assessment | Hong Kong MOntreal Cognitive Assessment (HK-MoCA) is a cognitive assessmenttool. Score from 0 to 30 . The lower score reflect the worse the outcome. | Baseline and 18 month | 
| Change of The Chinese Geriatric Depression Scale 30 | The Chinese Geriatric Depression Scale is used to detect depressive mood. Score 0 to 30. The higher the score, the worse the outcome | Baseline and 18 month | 
| Change of Pittsburgh sleep quality index | Pittsburgh sleep quality index Chinese Version is a self-report questionnaire that assesses sleep quality over a 1-month time interval. The questionnaire contains frequency questions related to sleep quality, each question scale from 0 to 3. The higher the score, the worse the outcome. There is no total score available for this assessment | Baseline and 18 month | 
| Change of Hong Kong List Learning Test | Hong Kong List Learning Test is memory test in Chinese designed for the assessment of the processes and organizational strategies involved in learning verbal information. The more negative the standard deviation the worse the outcome | Baseline and 18 month | 
| Food frequency questionnaire | The food frequency questionnaire serves the purpose of understanding the type of food that subject frequently consume in the past 12 months. There is no total score for this assessment. There is no positive and negative outcome available | Baseline | 
| Food frequency questionnaire | The food frequency questionnaire serves the purpose of understanding the type of food that subject frequently consume in the past 12 months. There is no total score for this assessment. There is no positive and negative outcome available | 18 month | 
| 24 hour food intake | The 24 hour food intake serves the purpose of understanding the food that subject consume on the day of urine collection There is no positive and negative outcome available | Baseline | 
| 24 hour food intake | The 24 hour food intake serves the purpose of understanding the food that subject consume on the day of urine collection There is no positive and negative outcome available | 18 Month | 
| Change of creatinine in urine | 24 hours of urine will be collected to measure the level of creatinine The higher the creatinine level the worse the outcome | Baseline and 18 month | 
| change of urinary potassium | 24 hours of urine will be collected to measure the level of potassium The higher the potassium level the worse the outcome | Baseline and 18 month | 
| Change of International Physical Activity Questionnaire | the International Physical Activity Questionnaire is a self report assessment to investigate the daily activities (frequency, duration, and level) of subject within the 7 days prior assessment There is no total score available for this questionnaire. The higher duration and frequency and level of daily activities the better outcome | Baseline and 18 month | 
| Change of Brain Peak Width of Skeletonized Mean Diffusivity | Peak Width of Skeletonized Mean Diffusivity is a robust, fully-automated and easy-to-implement marker for cerebral small vessel disease based on diffusion tensor imaging, white matter tract skeletonization and histogram analysis. It is a biomarker for brain MRI images. | Baseline and 18 month | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change of 24 hour blood pressure monitoring | Systolic and diastolic blood pressure will be measured using the 24-hour ambulatory blood pressure monitor. blood pressure will be measured at the same 24-hour period as urine measurement as blood | Baseline and 18 Month | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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CSVD