Ketogenic vs. Mediterranean Diet on Metabolic and Hormonal Parameters in Patients With Active Acromegaly

NCT ID: NCT07100587

Last Updated: 2025-09-05

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 26 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2024-06-30
• Study Completion Date: 2025-07-02

Brief Summary

This prospective, single-center, crossover study aims to evaluate the metabolic and hormonal effects of a ketogenic diet compared to a Mediterranean diet in patients with active acromegaly. Twenty-six adult patients with biochemically confirmed active acromegaly will undergo a three-week ketogenic diet followed by a three-week Mediterranean diet, with a two-week transitional phase. The primary outcome is the change in serum IGF-1 levels. Secondary outcomes include changes in anthropometric, biochemical, and inflammatory parameters. The study also explores the feasibility and safety of a structured ketogenic dietary intervention in this population.

Detailed Description

Acromegaly is a rare endocrine disorder characterized by excessive secretion of growth hormone (GH) and insulin-like growth factor 1 (IGF-1), often leading to metabolic complications including insulin resistance, diabetes mellitus, and hepatic steatosis. Nutritional status is a key regulator of the somatotropic axis, and recent evidence suggests that specific dietary patterns can modulate GH and IGF-1 secretion. The ketogenic diet (KD), characterized by high fat, moderate protein, and very low carbohydrate intake, induces nutritional ketosis, improves insulin sensitivity, and reduces circulating insulin levels. These effects may influence the hepatic expression of GH receptors and IGF-1 production. Preliminary data suggest that KD may reduce IGF-1 levels in patients with acromegaly.

This study is designed as a single-arm crossover trial involving 26 patients with active acromegaly. All participants will follow a structured ketogenic diet for three weeks (~1200 kcal/day, carbohydrates <30 g/day), followed by a two-week transition phase, and then a Mediterranean diet for three weeks (~1200 kcal/day, plant-based, rich in olive oil and fish). Baseline, post-KD, and post-Mediterranean assessments will include serum IGF-1 and GH levels, anthropometric measurements, body composition (via bioelectrical impedance analysis), liver enzymes, lipid profile, insulin resistance indices (HOMA-IR), and inflammatory markers (c-reactive protein, neutrophil to lymphocyte ratio, platelet to lymphocyte ratio).

The primary endpoint is the within-subject change in serum IGF-1 concentration. Secondary endpoints include changes in metabolic and inflammatory markers. Antidiabetic medications will be temporarily discontinued during the ketogenic phase under clinical supervision in patients not requiring insulin. The study is expected to provide novel insights into the impact of dietary modulation on the somatotropic axis in acromegaly and may inform future integrative therapeutic strategies.

Conditions

Acromegaly

Study Design

• Allocation Method: NON_RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: TREATMENT
• Blinding Strategy: SINGLE

Study Groups

Arm A - Ketogenic Diet (3 weeks)

Participants will follow a structured ketogenic diet for 3 weeks (\~1200 kcal/day, \<30 g/day carbohydrates) to induce nutritional ketosis.

Group Type: EXPERIMENTAL

Ketogenic diet

Intervention Type: BEHAVIORAL

A structured, equicaloric ketogenic diet providing approximately 1200 kcal/day, consisting of high fat (70-80 g/day), moderate protein (80-90 g/day), and very low carbohydrate intake (20-30 g/day), primarily from non-starchy vegetables. The diet is administered for 3 consecutive weeks to induce nutritional ketosis. A sugar-free multivitamin supplement is provided throughout the intervention.

Arm B: Mediterranean Diet

Following a 2-week transition phase, participants will switch to a Mediterranean diet for 3 weeks (\~1200 kcal/day), rich in olive oil, vegetables, whole grains, and moderate protein intake.

Group Type: ACTIVE_COMPARATOR

Mediterranean diet

Intervention Type: BEHAVIORAL

A structured Mediterranean diet administered for 3 weeks following a 2-week transition phase. The diet provides approximately 1200 kcal/day and emphasizes plant-based foods, extra virgin olive oil as the main fat source, moderate consumption of fish, dairy products, and whole grains, with limited red meat and processed foods.

Interventions

Ketogenic diet

A structured, equicaloric ketogenic diet providing approximately 1200 kcal/day, consisting of high fat (70-80 g/day), moderate protein (80-90 g/day), and very low carbohydrate intake (20-30 g/day), primarily from non-starchy vegetables. The diet is administered for 3 consecutive weeks to induce nutritional ketosis. A sugar-free multivitamin supplement is provided throughout the intervention.

Intervention Type: BEHAVIORAL

Mediterranean diet

A structured Mediterranean diet administered for 3 weeks following a 2-week transition phase. The diet provides approximately 1200 kcal/day and emphasizes plant-based foods, extra virgin olive oil as the main fat source, moderate consumption of fish, dairy products, and whole grains, with limited red meat and processed foods.

Intervention Type: BEHAVIORAL

Eligibility Criteria

Inclusion Criteria

• Age ≥ 18 years
• Confirmed diagnosis of active acromegaly (elevated IGF-1, GH non-suppressible at OGTT)
• Stable medical therapy for ≥ 3 months
• BMI 25-40 kg/m²
• Informed consent signed

Exclusion Criteria

• Type 1 diabetes or insulin-treated type 2 diabetes mellitus
• History of ketoacidosis
• Active malignancy, decompensated liver/kidney disease
• Severe psychiatric disorders or eating disorders
• Pregnancy or breastfeeding

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

University of Palermo

OTHER

Sponsor Role: lead

Responsible Party

Valentina Guarnotta

Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Locations

Policlinico Paolo Giaccone

Palermo, , Italy

Countries

Italy

Other Identifiers

14

Identifier Type: -

Identifier Source: org_study_id