Effects of Ketogenic Diet in Divers Breathing Enriched Air Nitrox

University of Padova

Status: Completed

Conditions: Overweight and Obesity; Oxygen Toxicity; Exertion; Excess

Treatments: Dietary Supplement: Ketogenic Diet

Study type: Interventional

Funder types: Other

Identifiers

NCT03114176

NEPL-DSB 06/16

Details and patient eligibility

About

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.

Enrollment: 6 patients

Sex: Male

Ages: 25 to 65 years old

Volunteers: Accepts Healthy Volunteers

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.

Trial design

Primary purpose: Prevention

Allocation: N/A

Interventional model: Single Group Assignment

Masking: None (Open label)

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6 participants in 1 patient group

Divers group

Experimental group

Description:

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 \[KETO-NTRX\]

Treatment:

Dietary Supplement: Ketogenic Diet