Impact of Mediterranean Diet in Cardiovascular Risk Among People With HIV

The VIHMET study aims to investigate the role of dietary optimization, specifically adopting a Mediterranean diet, in improving metabolic health, reducing immune activation, and mitigating cardiovascular risks in people living with HIV (PLWH) who are on antiretroviral therapy (ART). PLWH face unique challenges, including chronic immune activation and increased inflammation, which contribute to accelerated aging, metabolic complications, and a higher prevalence of cardiovascular disease (CVD) compared to the general population. This study hypothesizes that dietary interventions may reduce these risks, leading to better overall health outcomes.

Study Design

This randomized, prospective, open-label interventional study will recruit 64 participants from the HIV outpatient clinic at Hospital del Mar in Barcelona. Participants will be randomized into two groups: an intervention group and a control group ( 1 SoC:2 intervention ratio). The intervention group will receive personalized counseling to improve adherence to the Mediterranean diet, while the control group will receive general dietary recommendations. Each participant will be followed for 48 weeks, with clinical and laboratory evaluations conducted at baseline, week 24, and week 48.

Study Objectives

Primary Objectives:

To evaluate changes in lipid profiles (total cholesterol, LDL, HDL, and triglycerides) at weeks 24 and 48.

To assess reductions in immune activation markers and inflammatory cytokines, such as IL-6, TNF-alpha, and sCD14.

To measure improvements in arterial stiffness using pulse wave velocity (PWV) as an indicator of subclinical CVD.

To assess the impact of the intervention on adherence to the Mediterranean diet using the MEDAS score.

Secondary Objectives:

To evaluate changes in quality of life using the EQ-5D questionnaire. To analyze changes in body composition, including BMI, waist circumference, and weight.

To assess reductions in TMAO (trimethylamine-N-oxide), a biomarker linked to CVD risk.

To investigate the presence and composition of coronary atherosclerosis using non-invasive coronary CT angiography (CCTA).

Participant Eligibility

Inclusion Criteria:

Adults aged 18 years or older. Confirmed HIV diagnosis. On stable ART with an undetectable viral load for at least 12 months. LDL cholesterol >140 mg/dL. Mediterranean Diet Adherence Screener (MEDAS) score <9, indicating low adherence.

Exclusion Criteria:

Use of lipid-lowering medications or chronic anti-inflammatory drugs. Active hepatitis B or C or other chronic inflammatory conditions. Familial hypercholesterolemia. Uncontrolled hypothyroidism or diabetes mellitus. Inability to provide informed consent.

Interventions Ratio: 1 SoC : 2 intervention

Intervention Group: Participants in the intervention group will undergo tailored nutritional counseling focusing on the Mediterranean diet. Key components include:

Education on food selection and preparation, emphasizing fruits, vegetables, whole grains, olive oil, nuts, and fish.

Guidance on reducing saturated fats and sugars. Development of individualized meal plans considering dietary habits and socioeconomic status.

Scheduled virtual follow-ups at weeks 4 and 12 to review adherence and address challenges.

Control Group: Participants will receive general dietary advice provided through standard informational leaflets. No individualized or follow-up counseling will be provided.

Outcome Measures

Primary Outcomes:

Changes in lipid profiles (total cholesterol, LDL, HDL, and triglycerides) at week 24 and 48 respect to baseline Reductions in inflammatory and immune activation markers (IL-6, TNF-alpha, sCD163, and sCD14) at week 24 and 48 respect to baseline Improvements in arterial stiffness as measured by PWV at week 24 and 48 respect to baseline

Secondary Outcomes:

Improvements in MEDAS scores, indicating better adherence to the Mediterranean diet at week 24 and 48 respect to baseline Changes in TMAO levels, reflecting reduced CVD risk at week 24 and 48 respect to baseline Alterations in quality of life (EQ-5D scores) at week 24 and 48 respect to baseline Presence and composition of coronary plaques using CCTA.

Procedures and Assessments

Participants will attend clinical visits at baseline, week 24, and week 48. The following assessments will be conducted:

Clinical Data Collection:

Medical history, HIV-related parameters, and medication use. Anthropometric Measurements: BMI, waist circumference, and weight. Dietary Adherence: MEDAS score and food frequency questionnaires. Laboratory Tests: Lipid profiles, inflammatory markers, immune activation biomarkers, and TMAO levels.

Imaging: Pulse wave velocity and CCTA to evaluate arterial health and coronary plaque burden.The study aims to demonstrate the benefits of dietary interventions in reducing CVD and metabolic risks, offering a holistic approach to HIV care that integrates nutritional counseling for long-term health improvements.

Statistical Analysis

Data will be analyzed using appropriate statistical methods. Continuous variables will be expressed as means and standard deviations, while categorical variables will be reported as frequencies. Comparisons between groups will be performed using t-tests or non-parametric equivalents, depending on data distribution. Multivariate regression models will assess the independent effects of dietary intervention on primary and secondary outcomes. All analyses will be conducted using Stata software, and a p-value <0.05 will be considered statistically significant. A sample size of 60 participants (40 in the intervention group and 20 in the control group) provides adequate power to detect clinically significant changes in LDL cholesterol and other outcomes.

Ethical Considerations

The study adheres to the Declaration of Helsinki and Good Clinical Practice (GCP) guidelines. All participants will provide written informed consent, and data confidentiality will be maintained according to GDPR standards. Participants will not receive financial compensation but will benefit from detailed health assessments and personalized dietary guidance.

Expected Impact

This study is expected to provide valuable insights into the role of dietary optimization in reducing cardiovascular and metabolic risks in PLWH. By addressing chronic inflammation, lipid disturbances, and immune activation, the findings could inform new strategies for integrating dietary counseling into HIV care. Such an approach emphasizes a holistic perspective, considering not only virological control but also long-term health and quality of life. The VIHMET study could represent a significant step forward in personalized care for PLWH, with potential applications in broader chronic disease management.