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Completed

NCT Number: NCT06538324

Response to an Intervention With Omega-3 (RIO - Study)

The RIO-Study project is a randomized, controlled, double-blind, crossover trial aimed at determining the effectiveness of omega-3 fatty acids at nutritional doses on lipid metabolism and inflammation in overweight and obese individuals with hypertriglyceridemia in Chile.

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Key information

Age range

18 year–65 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Universidad San Sebastián

Valdivia, Los Ríos Region, 5090000, Chile

About this study

The study will include 40 participants (each participant will serve as their own control) aged 18-65, with 25-34.9 kg/m2 BMI and fasting triglycerides (TG) of 100-215 mg/dL. The intervention consists of 250 mg EPA from algae oil versus high oleic sunflower oil (HOSO) for 6 weeks each, after a 10-week washout period, the treatments will be switched for another 6 weeks, considering four visits during the whole study. The main outcomes to be evaluated are serum triglyceride levels, expression of target genes in peripheral blood mononuclear cells (PBMCs), low-grade inflammation biomarkers, and very low-density lipoprotein (VLDL) atherogenic properties. The study also analyzes background diet, chrononutrition, and physical activity aspects. Results are expected to provide new insights into the effects of nutritional doses of omega-3 in the Chilean population, particularly on fasting and postprandial triglyceride metabolism and cardiovascular disease risk reduction.

Before and after each intervention period, fasting blood samples will be collected. On each visit day, participants will consume a standardized breakfast (three slices of white bread with butter and jam), and postprandial blood samples will be taken at 0, 2, 4, and 6 hours to measure triglycerides and other lipid parameters.

The study will assess:

  • Serum triglyceride levels in fasting and postprandial states
  • Expression of target genes Peroxisome proliferator-activated receptor alpha (PPARα) and Sterol regulatory element binding protein-1 (SREBP1c) in peripheral blood mononuclear cells (PBMCs) at fasting (0h) and postprandial (4h) states
  • Levels of low-grade inflammation biomarkers Tumor Necrosis Factor-Alpha (TNFα) and Interleukin 6 ( IL-6) at fasting (0h) and postprandial (4h) states
  • Very low-density lipoprotein (VLDL) atherogenic properties in the fasting state Additionally, the investigators will collect data on chrononutrition, physical activity, and energy drink intake to understand their impact on lipid metabolism. Anthropometric measurements and bioimpedance analysis will be performed at each visit.

The study will collaborate with international partners for specialized analyses, including gene expression studies and VLDL atherogenic properties assessment.

This comprehensive approach aims to provide new insights into the effects of nutritional doses of omega-3 fatty acids on lipid metabolism and inflammation in the Chilean population, with a particular focus on postprandial triglyceride metabolism and cardiovascular disease risk reduction.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Adults between 18 and 65 years old, male and female.
  • Body mass index (BMI) between 25 - 34,9 kg/m2.
  • Fasting triglycerides between 100-215 mg/dL (1.13-2.43 mmol/L).

Exclusion criteria

  • Unable to give informed consent.
  • If you consume Omega-3 (you must stop consumption at least 10 weeks prior).
  • Normal or Obesity Nutritional Status. Large weight variation (>10%) in the last 3 months.
  • Triglycerides > 215 mg/dL.
  • Blood pressure > 140/90 mmHg.
  • Uncontrolled metabolic and chronic diseases (reference parameters for the disease in question will be considered).
  • Pregnant women or those who are breastfeeding.
  • Allergy or intolerance to gluten, milk protein and/or lactose, or any ingredient in the capsules (omega-3, oleic acid oil).
  • Use of medications that affect lipid metabolism: Fibrates. (Statins will be allowed only if the treatment has been ongoing for over 3 months).
  • Blood donation two months before or during the study period.
  • Excessive alcohol consumption (>3 cans of beer per day)
  • Taking anticoagulants.

Treatment and study plan

Omega-3

Dietary Supplement

Dietary Supplement: Omega-3 In the marine Omega-3 fatty acid period, the participants will receive a capsule with 250 mg of EPA per day during 6 weeks.

HOSO

Dietary Supplement

Dietary Supplement: HOSO In the HOSO period, the participants will receive a capsule with the similar weight of HOSO per day during 6 weeks.

Primary outcomes

  1. Fasting TG (mg/dL)

    Time frame: up to 6 weeks

    Baseline serum levels of circulating triglycerides

Secondary outcomes

  1. Postprandial TG (mg/dL)

    Time frame: up to 6 weeks

    Triglyceride concentration (mg/dL) measured by enzymatic colorimetric assay at baseline (fasting) and at 2, 4, and 6 hours after consumption of a standardized 50 g fat meal.

  2. Change in mRNA expression levels of lipid metabolism genes in Peripheral Blood Mononuclear Cells (PBMCs)

    Time frame: up to 6 weeks

    Fold change in mRNA expression of genes of lipid metabolism in PBMCs at 0h and 4h, measured by RT-qPCR

  3. Change in concentrations (pg/mL) of pro-inflammatory cytokines TNF-α and IL-6

    Time frame: up to 6 weeks

    Serum concentrations (pg/mL) of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) measured by enzyme-linked immunosorbent assay (ELISA) at fasting (0h) and 4 hours postprandial following a standardized test meal

  4. Fasting serum Low-Density Lipoproteins, High-Density Lipoproteins, Very Low-Density Lipoproteins (mg/dL)

    Time frame: up to 6 weeks

    Fasting levels before and after intake of omega-3 or HOSO

  5. Fasting plasma glucose concentration (mg/dL)

    Time frame: up to 6 weeks

    Fasting levels before and after intake of omega-3 or HOSO

Sponsors and collaborators

Lead sponsor

Universidad San Sebastián

Other

Registry information

Official study title

Response to an Intervention With Omega-3 Fatty Acids on Lipid and Inflammatory Profiles in Overweight and Obese Individuals With Hypertriglyceridemia in Valdivia, Chile (RIO - Study)

Acronym: RIO

Important dates

Study start
2024
Primary completion
2025
Study completion
2025
First posted
Aug 5, 2024
Registry last updated
Sep 25, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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