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CompletedNCT03267901Updated Aug 30, 2017

Effects of Daily Walnut Intake Among the Subjects With Metabolic Syndrome

An interventional study of food in Metabolic Syndrome, sponsored by ICAN Nutrition Education and Research. Completed at 1 site in Korea, Republic of. Open to participants aged 30 Years to 55 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2017-08-30.

Sponsored by ICAN Nutrition Education and Research · Not applicable, Interventional, and Treatment

Phase
Not applicable
Study type
Interventional
Enrollment
119
Allocation
Randomized
Ages
30 Years to 55 Years
Sex
All
01

Study summary

Investigators planed to conduct a randomized, controlled, crossover trial to examine the effects of daily walnuts intake among Korean subjects with metabolic syndrome. Primary objective of this study was to investigate the effects of daily walnut intake on changes of metabolic syndrome indices in Koreans with metabolic syndrome age over 30 years old. This study was consisted of four periods: run-in, first intervention, wash-out, and second intervention phases. As 16 weeks of first intervention period began after the run-in phase, the subjects were randomly assigned into one of two groups: walnut group and control group. Participants in walnut group consumed 45 grams of walnuts on a daily basis and participants in control group were provided iso-caloric white bread for first 16 weeks. After the first intervention and wash-out period (6 weeks), second intervention which is crossover of first intervention was started during the next 16 weeks. Anthropometric measurements and biochemical analyses were done at the beginning and the end of each intervention (0, 16, 22, and 38 weeks of trial). Habitual diet was randomly observed using 3-day diet record once during each phase.

Investigators expected to evaluate 1)effects of walnut ingestion on reverting metabolic syndrome to normal status especially by reducing waist circumference and improving serum levels of triglyceride and high-density lipoprotein, 2)beneficial effects of daily walnut consumption on changes of body composition in the subjects with metabolic syndrome, and 3)regulatory effects of daily walnut intake on inflammatory markers and diabetic markers.

02

Conditions studied

  • Metabolic Syndrome
03

Who can participate

Ages eligible
30 Years to 55 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

Eligibility criteria

Inclusion Criteria: at least three out of five metabolic syndrome components

  • waist circumference (WC) >90 cm for men and >80 cm for women
  • hypertension (DBP ≥85 and \<110 mm Hg)
  • hyperglycemia (≥100 mg/dL)
  • elevated plasma TG concentrations (≥150 mg/dL)
  • decreased plasma HDL-C concentrations (\<40 mg/dL for men and \<50 mg/dL for women)

Exclusion Criteria:

  • the presence of morbid obesity (BMI ≥40)
  • the use of any medication for the control of blood pressure, glucose, or lipid metabolism
  • a medical history of hypocaloric diet consumption within the past year
  • gastrointestinal tract disorders
  • post-menopausal women
  • smokers
04

Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Crossover assignment
Masking
Double (Investigator, Outcomes assessor)
Enrollment
119 participants (actual)

Study arms

  • Experimental
    Walnut-Control

    Other: food

  • Experimental
    Control-Walnut

    Other: food

Interventions

  • Otherfood

    45 g of walnut / iso-caloric white bread

05

What researchers measure

Primary outcomes

  1. changes of waist circumference

    Waist circumferences (cm) were obtained at the midpoint between the lowest rib and the iliac crest and rounded to the nearest 0.1 cm after inhalation and exhalation.

    Time frame: after 16 weeks of daily walnut consumption

  2. changes of blood triglyceride level

    Serum triglycerides (mg/dL) levels were measured by an enzymatic-colorimetric method.

    Time frame: after 16 weeks of daily walnut consumption

  3. changes of blood high-density lipoprotein cholesterol levels

    High density lipoprotein cholesterol (mg/dL) levels were determined by a homogeneous enzymatic-colorimetric method.

    Time frame: after 16 weeks of daily walnut consumption

  4. changes of blood pressure

    Blood pressure (mmHg) was measured on the right arm using an up-load blood pressure monitor with participants in a comfortably seated position after at least a 5-minute rest.

    Time frame: after 16 weeks of daily walnut consumption

  5. changes of blood glucose level

    Blood glucose levels (mg/dL) were measured using blood glucose monitor and test stripts from the finger tip.

    Time frame: after 16 weeks of daily walnut consumption

Secondary outcomes

  1. changes of total cholesterol level

    Serum total cholesterol levels (ml/dL) were measured by an enzymatic-colorimetric method.

    Time frame: after 16 weeks of daily walnut consumption

  2. changes of serum apolipoprotein B level

    Serum apolipoprotein B (ml/dL) was measured using a turbidimetric immunoassay.

    Time frame: after 16 weeks of daily walnut consumption

  3. changes of serum adiponectin level

    Blood adiponectin (ug/mL) levels were measured using ELISA.

    Time frame: after 16 weeks of daily walnut consumption

  4. changes of serum leptin level

    Blood leptin (ug/mL) levels were measured using ELISA.

    Time frame: after 16 weeks of daily walnut consumption

  5. changes of serum insulin level

    Serum insulin (μU/mL) was measured with a commercially available kit, the ultrasensitive insulin ELISA kit using an Epoch microplate spectrophotometer.

    Time frame: after 16 weeks of daily walnut consumption

  6. changes of low-density lipoprotein cholesterol level

    Low-density lipoprotein cholesterol levels (ml/dL) were determined by a homogeneous enzymatic-colorimetric method.

    Time frame: after 16 weeks of daily walnut consumption

06

Study locations

1 site
  • ICAN Nutrition Education and Research
    Seoul, 07327, Korea, Republic of
07

References and documents

Publications

  • Hwang HJ, Liu Y, Kim HS, Lee H, Lim Y, Park H. Daily walnut intake improves metabolic syndrome status and increases circulating adiponectin levels: randomized controlled crossover trial. Nutr Res Pract. 2019 Apr;13(2):105-114. doi: 10.4162/nrp.2019.13.2.105. Epub 2019 Feb 11. PubMed 30984354 ↗

Individual participant data

Plan to share: Undecided

08

Registry details

Key details

Study ID
NCT03267901
Lead sponsor
ICAN Nutrition Education and Research
Collaborators
California Walnut Commission
Responsible party
Sponsor
First posted
Aug 30, 2017
Start date
May 1, 2015
Primary completion
Jul 30, 2017
Completion
Jul 30, 2017
Last update
Aug 30, 2017

Oversight

FDA-regulated drug
No
FDA-regulated device
No
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