The primary objective is to evaluate in elderly men and women the effect of 16-week mixed nut consumption on cerebral blood flow, as quantified by the non-invasive gold standard magnetic resonance imaging (MRI)-perfusion method Arterial Spin…
ID
Source
Brief title
Condition
- Glucose metabolism disorders (incl diabetes mellitus)
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
At baseline, first anthropometric measurements will be performed and blood
pressure will be determined. In addition, a fasting blood sample will be drawn.
Another fasting blood sample will be draw at eight weeks, while participants
have to attend the research facilities two times to perform follow-up
measurements after sixteen weeks. The primary endpoint is the difference at
follow-up in cerebral blood flow, as assessed by ASL, between interventions.
Secondary outcome
Secondary endpoints are the cerebral blood flow response to intranasal insulin
delivery as quantified by ASL, and cognitive functioning as assessed with a
neuropsychological test battery.
Background summary
Impaired brain vascular function precedes the development of reduced cognitive
performance, while brain insulin-resistance is also associated with cognitive
decline. The Mediterranean diet, which is rich in nuts, may protect against the
development of impaired cognitive performance. We hypothesize that long-term
mixed nut consumption increases brain insulin-sensitivity thereby improving
brain vascular function and cognitive performance.
Study objective
The primary objective is to evaluate in elderly men and women the effect of
16-week mixed nut consumption on cerebral blood flow, as quantified by the
non-invasive gold standard magnetic resonance imaging (MRI)-perfusion method
Arterial Spin Labelling (ASL). Cerebral blood flow is a robust and sensitive
physiological marker of brain vascular function. Secondary objectives are to
investigate effects on the cerebral blood flow response to intranasal insulin
delivery - a marker of insulin-sensitivity in the human brain - as quantified
by ASL, and cognitive functioning as assessed with a neuropsychological test
battery.
Study design
This intervention study will have a randomized, controlled, cross-over design.
The total study duration will be 40 weeks, including two 16-week interventions,
separated by a washout period of at least 8 weeks.
Intervention
Subjects will receive in random order daily 60 g of mixed nuts (15 g of
walnuts, 15 g of cashews, 15 g of hazelnuts, and 15 g of pistachios) (nut
intervention) or no nuts for 16 weeks (control intervention), separated by a
wash-out period of at least 8 weeks.
Study burden and risks
Subjects will be screened to determine eligibility during one visit of 20
minutes. During these screening visits, anthropometric measurements will be
performed and blood pressure will be determined. In addition, a fasting blood
sample (5.5 mL) will be drawn. During nut intervention, adults will receive
daily 60 g of mixed nuts for sixteen weeks. These regimens were well-tolerated
in previous trials and are safe, and there are no expected side effects related
to the nut consumption. During the trial on different occasions, tests will be
performed and blood will be sampled (a total of 325.5 mL during the whole
trial). During these tests, subjects have to stay at the university and are not
allowed to eat. Some subjects may report pain during venipuncture. Insertion of
the cannula can cause some discomfort and possible a hematoma or bruise. Some
adults may also report pain during the insertion of the cannula. ASL perfusion
MRI non-invasively records cerebral blood flow without any significant risks.
Measurements will be performed on a Siemens 3.0 Tesla Magnetom Prisma Fit
scanner. No contrast medication or radioactive tracer substance will be
administered. Brain insulin-sensitivity will be assessed by quantifying acute
effects of insulin as nasal spray on cerebral blood flow, which is safe and
follows what is being used by experts at the University of Tübingen (Germany)
and Leiden University Medical Centre (protocol code numbers P13.164 and
NL45043.058.13), who we are closely collaborating with. Other measurements are
routine and are also not expected to lead to physical side effects.
Participants that not fully adhere to the study protocol will be excluded from
the statistical analyses, because a per protocol analysis will be performed.
The total time investment is 19 hours (1140 minutes), excluding travel time.
The study will provide insight into the potential beneficial effect of mixed
nuts on brain vascular function in elderly adults.
Universiteitsingel 50
Maastricht 6229 ER
NL
Universiteitsingel 50
Maastricht 6229 ER
NL
Listed location countries
Age
Inclusion criteria
- Aged between 60-70 years
- BMI between 25-35 kg/m2
- Fasting plasma glucose < 7.0 mmol/L
- Fasting serum total cholesterol < 8.0 mmol/L
- Fasting serum triacylglycerol < 4.5 mmol/L
- Systolic blood pressure < 160 mmHg and diastolic blood pressure < 100 mmHg
- Stable body weight (weight gain or loss < 3 kg in the past three months)
- Willingness to give up being a blood donor from 8 weeks before the start of
the study, during the study and for 4 weeks after completion of the study
- No difficult venipuncture as evidenced during the screening visit
Exclusion criteria
- Allergy or intolerance to nuts
- Left handedness
- Current smoker, or smoking cessation < 12 months
- Diabetic patients
- Familial hypercholesterolemia
- Abuse of drugs
- More than 3 alcoholic consumptions per day
- Use of nuts or dietary supplements known to interfere with the main outcomes
as judged by the principal investigators
- Use medication to treat blood pressure, lipid or glucose metabolism
- Use of an investigational product within another biomedical intervention
trial within the previous 1-month
- Severe medical conditions that might interfere with the study, such as
epilepsy, asthma, kidney failure or renal insufficiency, chronic obstructive
pulmonary disease, inflammatory bowel diseases, auto inflammatory diseases and
rheumatoid arthritis
- Active cardiovascular disease like congestive heart failure or cardiovascular
event, such as an acute myocardial infarction or cerebrovascular accident
- Contra-indications for MRI imaging (e.g. pacemaker, surgical clips/material
in body, metal splinter in eye, claustrophobia)
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| CCMO | NL71168.068.19 |