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Effects of Ketogenic Diet in Divers Breathing Enriched Air Nitrox

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT03114176
Recruitment Status : Completed
First Posted : April 14, 2017
Last Update Posted : April 14, 2017
Information provided by (Responsible Party):
Antonio Paoli, University of Padova

Brief Summary:

Overweight divers face a challenging activity such as immersions, starting from a higher levels of circulating cytokines and oxidative stress. Ketogenic Diet (KD) is described as effective in weight loss, in countering inflammation and oxidative stress, and used in the control of drug-refractory seizures.

The aim of our pilot study was to evaluate if a ketosis state induced by a specific dietary regime, may have a protective effect on oxidative stress damages and inflammatory status, that accompanies both overweight and diving activities.

Blood and urine samples from six overweight divers were obtained a) before (CTRL) and after a dive breathing Enriched Air Nitrox and performing light underwater exercise (NTRX), b) after a dive (same conditions) performed after 7 days of KD (K-NTRX). We measured urinary 8-isoprostane and 8-OH-2-deoxyguanosine evaluating lipids peroxidation and DNA oxidative damages. Plasmatic IL-1beta, IL-6 and TNF-alpha levels were measured to investigate the inflammatory status.

Condition or disease Intervention/treatment Phase
Overweight and Obesity Exertion; Excess Oxygen Toxicity Dietary Supplement: Ketogenic Diet Not Applicable

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 6 participants
Allocation: N/A
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Prevention
Official Title: Effects of Exercise and Dietary Inatke on Muscle Metabolism and Inflammatory Status Modulated by Oxygen Free Radicals and Cytokines in Humans
Actual Study Start Date : May 25, 2016
Actual Primary Completion Date : July 10, 2016
Actual Study Completion Date : July 10, 2016

Resource links provided by the National Library of Medicine

Drug Information available for: Nitrox

Arm Intervention/treatment
Experimental: Divers group
Throughout each dive, subjects performed a 20-minute long mild exercise on an underwater bike. The depth of dive was set at 15 meters, where the subjects performed an activity guided by Borg CR-10 scale at intensity level 3 (25 rpm). The ascent rate was set at 10 m/min, with a decompression stop at 5 meters for 3 min, according to the US Navy Manual Diving Table. 48 h prior to the immersions, none of the participants consumed medications or dived or flew. In the first part of the experiment, all subjects performed a dive breathing Enriched Air Nitrox (EAN, 32% ppO2). Baseline clinical measurements were collected before and after this first dive in order to have a reference [CTRL] and to measure physiological modifications due to immersion [NTRX]. After twenty days of no diving activity, subjects were engaged in a KD for seven days. At the end of this period, subjects performed a single immersion breathing EAN. The measures were performed after this single dive [KETO-NTRX]
Dietary Supplement: Ketogenic Diet
Diet consisted of a very low carbohydrate ketogenic diet (for 7 days) with the use of some phytoextracts as previously described. The consumed diet was primarily made of beef and veal, poultry, fish, raw and cooked green vegetables without restrictions, cold cuts (dried beef, carpaccio and cured ham), eggs and seasoned cheese (e.g., parmesan). The allowed drinks were infused tea, moka coffee and herbal extracts. The foods and drinks that subjects had to avoid included alcohol, bread, pasta, rice, milk, yogurt, soluble tea, and barley coffee. To facilitate adherence to the nutritional regime, a variety of special meals based on protein and fibers were given to each subject. KD characteristics are protein intake 1.3g/kg/day, to maintain skeletal muscle mass; carbohydrates intake less than 40 g/day and 50-60% of total kcal to induce ketosis. In accordance with a hypocaloric profile, total energy intake was calculated with 200 kcal more than basal metabolic rate.

Primary Outcome Measures :
  1. Oxidative damage change [ Time Frame: Change from Baseline Oxidative damage at twenty days ]
    8-OH-dG (ng ⋅ mg-1 creatinine) and 8-iso-PGF2α (ng ⋅ mg-1 creatinine)

  2. Pro-inflammatory cytokines change [ Time Frame: Change from Baseline Pro-inflammatory cytokines at twenty days ]
    IL-1β (pg/ml), IL-6 (pg/ml) and TNF- α (pg/ml)

Secondary Outcome Measures :
  1. Weight Loss [ Time Frame: Weight was registered before (T0) and after twenty days of no diving activity in which subjects were engaged in a 7-days Ketogenic Diet (T3). ]
    Kilogram (Kg)

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Ages Eligible for Study:   25 Years to 65 Years   (Adult, Older Adult)
Sexes Eligible for Study:   Male
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • to be in an overweight state (BMI ≥ 25 kg/m2) and no history of orthopedic, cardiovascular, renal or metabolic disorders.

Exclusion Criteria:

  • not to be in an overweight state (BMI ≥ 25 kg/m2) and a history of orthopedic, cardiovascular, renal or metabolic disorders.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT03114176

Sponsors and Collaborators
University of Padova
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Study Director: Bosco Gerardo, MD, PhD University of Padova
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Responsible Party: Antonio Paoli, Associate Professor, University of Padova Identifier: NCT03114176    
Other Study ID Numbers: NEPL-DSB 06/16
First Posted: April 14, 2017    Key Record Dates
Last Update Posted: April 14, 2017
Last Verified: April 2017
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Product Manufactured in and Exported from the U.S.: No
Additional relevant MeSH terms:
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Body Weight