Mechanisms of Impaired Brain Blood Flow With Aging

NCT ID: NCT03775382

Last Updated: 2023-05-10

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 34 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2017-10-30
• Study Completion Date: 2022-06-01

Brief Summary

Aging is the primary risk factor for Alzheimer's disease (AD), which is a rapidly growing public health concern. Understanding the mechanisms of normal brain aging may provide insight into the factors linking advancing age to increased risk for AD and thereby lead to new therapeutic targets for preventing or slowing AD progression. Cardiovascular changes, including impaired cerebrovascular function, occur with aging and may increase risk for AD; however, the mechanisms by which cerebrovascular function becomes impaired in older adults are incompletely understood. The overall goal of this project is to examine potential mechanisms of age-related declines in cerebrovascular function in humans. The investigators hypothesize that brain macro-vascular endothelial dysfunction, secondary to oxidative stress, plays an important role in mediating age-related changes in brain blood flow and cerebrovascular reactivity. The results of this pilot study have the potential to identify novel targets of cerebrovascular aging and will help guide the design of future clinical trials aimed at improving cerebral blood flow in older adults.

Conditions

Aging

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: TRIPLE

Study Groups

Placebo

Normal saline will be infused by the research nurse into an antecubital vein using an IV infusion pump.

Group Type: PLACEBO_COMPARATOR

Normal Saline

Intervention Type: OTHER

Normal saline will be infused by the research nurse into an antecubital vein using an IV infusion pump.

Ascorbic Acid

Ascorbic acid will be measured into sterile syringes by the research nurse and infused into an antecubital vein using a IV infusion pump beginning with a priming bolus of 0.06 g Ascorbic Acid per kg fat-free mass dissolved in 100 ml of saline or lactated ringers followed by a "drip-infusion" of 0.02 g Ascorbic Acid per kg fat-free mass dissolved in 30 ml of saline.

Group Type: ACTIVE_COMPARATOR

Ascorbic Acid

Intervention Type: OTHER

Ascorbic acid will be infused into an antecubital vein using a IV infusion pump beginning with a priming bolus of 0.06 g Ascorbic Acid per kg fat-free mass dissolved in 100 ml of saline followed by a "drip-infusion" of 0.02 g Ascorbic Acid per kg fat-free mass dissolved in 30 ml of saline.

Interventions

Ascorbic Acid

Ascorbic acid will be infused into an antecubital vein using a IV infusion pump beginning with a priming bolus of 0.06 g Ascorbic Acid per kg fat-free mass dissolved in 100 ml of saline followed by a "drip-infusion" of 0.02 g Ascorbic Acid per kg fat-free mass dissolved in 30 ml of saline.

Intervention Type: OTHER

Normal Saline

Normal saline will be infused by the research nurse into an antecubital vein using an IV infusion pump.

Intervention Type: OTHER

Other Intervention Names

Vitamin C

Eligibility Criteria

Inclusion Criteria

• 18-29 or 55-79 years old

Exclusion Criteria

• Pregnancy or breastfeeding;
• Blood chemistries indicative of abnormal renal, liver, thyroid and adrenal function (i.e., outside of normal reference range); estimated glomerular filtration rate using the MDRD prediction equation must be >60 ml/min/1.73 m2;
• Abnormal blood chemistry that is clinically relevant or any blood chemistry marker that is +/-2.5x the upper or lower limit;
• Lack of a suitable temporal window for cerebrovascular assessments;
• Current smoking;
• Chronic clinical diseases (e.g., coronary artery, peripheral artery, or cerebrovascular diseases, diabetes, chronic kidney disease, COPD);
• Major psychiatric disorder (e.g. Alzheimer's disease or other form of dementia, schizophrenia, bipolar disorder, major depression within past two years);
• Neurological or autoimmune conditions affecting cognition (e.g. Parkinson's disease, epilepsy, multiple sclerosis, head trauma with loss of consciousness greater than 30 min, large vessel infarct);
• Current medication use likely to affect CNS functions (e.g. long active benzodiazepines);
• Having past or present alcohol dependence or abuse, as defined by the American Psychiatry Association, Diagnostic and Statistical Manual of Mental Disorders;
• Body mass index (BMI) >40 kg/m2 (FMD measurements can be inaccurate in severely obese patients).

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 79 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

University of Delaware

OTHER

Sponsor Role: lead

Responsible Party

Christopher Martens

Assistant Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Christopher R Martens, Ph.D.

Role: PRINCIPAL_INVESTIGATOR

University of Delaware

Locations

Neurovascular Aging Laboratory

Newark, Delaware, United States

Countries

United States

Other Identifiers

Martens - 1138735

Identifier Type: -

Identifier Source: org_study_id