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Exercise and Coronary Heart Disease Risk Markers in Male Smokers and Non-Smokers

Not Applicable
Completed
Conditions
Inflammation
Oxidative Stress
Cigarette Smoking
Coronary Heart Disease
Cardiovascular Risk Factor
Insulin Resistance
Interventions
Behavioral: Exercise
Registration Number
NCT03735186
Lead Sponsor
Loughborough University
Brief Summary

The present study will investigate the effect of acute exercise on fasting and postprandial risk markers for coronary heart disease (CHD) in healthy male cigarette smokers and non-smokers.

Participants will complete two, 2-day trials in a random crossover design separated by an interval of at least 1 week. On day 1, participants will rest (control) or complete 60 minute of treadmill exercise at 60% of maximum oxygen uptake (exercise). On day 2, participants will rest and consume two high fat meals (breakfast and lunch) over an 8-h period during which 13 venous blood samples and nine blood pressure measurements will be taken at pre-determined intervals.

It is hypothesised that men who smoke cigarettes will exhibit impaired fasting and postprandial metabolic risk markers compared to non-smokers, but a single bout of exercise will be equally, if not more, efficacious for improving the CHD risk factor profile in smokers than non-smokers.

Detailed Description

Cigarette smoking is a strong and independent risk factor for CHD and is associated with impaired postprandial metabolism. Previous studies suggest that postprandial metabolism and other risk markers for CHD can be improved with acute exercise in healthy non-smokers, but less is known about responses in cigarette smokers. Therefore, the present study will compare the effect of acute exercise on fasting and postprandial risk markers for CHD in healthy male cigarette smokers and non-smokers.

A total of 12 healthy male cigarette smokers and 12 healthy male non-smokers matched for age and body mass index will be recruited. Before the main experimental trials, participants will attend the laboratory for a preliminary visit to complete screening questionnaires and to undergo familiarisation, anthropometric measurements (stature, body mass, waist and hip circumference, body fat) and exercise testing to determine maximum oxygen uptake.

Participants will complete two, 2-day (08:00-17:00) experimental trials in a randomised cross over design: control and exercise. On day 1, participants will arrive at the laboratory at 08:00 having fasted overnight and a baseline fasting venous blood sample and blood pressure measurement will be taken. A high fat breakfast and lunch meal will be consumed at 08:30 and 12:00, respectively. The control and exercise trials will be identical, except a 60 min bout of treadmill exercise at 60% of maximum oxygen uptake will be performed at 14:30 in the exercise trial.

On day 2, participants will arrive at 08:00 having fasted overnight for 10 h and will rest in the laboratory until 17:00. Participants in the smokers group will be asked to stop smoking at 08:00. A high fat breakfast and lunch will be consumed at 09:00 and 13:00, respectively. Venous blood samples from a cannula will be collected in the fasted state and at 0.25, 0.5, 1, 2, 3, 4, 4.25, 4.5, 5, 6, 7 and 8 h after the breakfast meal. Resting arterial blood pressure will be measured in the fasted state and at hourly intervals thereafter.

Recruitment & Eligibility

Status
COMPLETED
Sex
Male
Target Recruitment
24
Inclusion Criteria

Not provided

Exclusion Criteria
  • Not meeting the criteria for a smoker or non-smoker (defined above);
  • Current E-Cigarette smoker;
  • Musculoskeletal injury that has affected normal ambulation within the last month;
  • Any muscle or bone injuries that do not allow them to walk and run on a treadmill;
  • Uncontrolled exercise-induced asthma;
  • Heart conditions;
  • Coagulation or bleeding disorders;
  • Diabetes (metabolism will be different to non-diabetics potentially skewing the data);
  • Taking any medication that might influence fat metabolism;
  • Taking any medication that might influence blood glucose (e.g., insulin for diabetes);
  • Dieting or restrained eating behaviours;
  • Weight fluctuation greater than 3 kg in the 3 months prior to study enrolment;
  • A food allergy.

Study & Design

Study Type
INTERVENTIONAL
Study Design
CROSSOVER
Arm && Interventions
GroupInterventionDescription
ExerciseExerciseParticipants will complete 60 min of treadmill exercise on day 1 (14:30-15:30). Participants will rest in the laboratory for the remainder of day 1 and throughout day 2 (08:00-17:00). A high fat breakfast and lunch will be consumed on both days at pre-determined intervals.
Primary Outcome Measures
NameTimeMethod
Triacylglycerol concentration8 hours (Plasma samples will be collected at 0 (fasted), 0.25, 0.5, 1, 2, 3, 4, 4.25, 4.5, 5, 6, 7, 8 hours)

Total area under the plasma triacylglycerol concentration versus time curve on day 2

Secondary Outcome Measures
NameTimeMethod
High-density lipoprotein cholesterol concentrationFasting (Plasma samples will be collected at 0 (fasted) hours)

Circulating concentrations of plasma high-density lipoprotein cholesterol in the fasted state on day 2 of the exercise and control trials.

Peroxiredoxin-4 concentration8 hours (Plasma samples will be collected at 0 (fasted), 2, 5, 8 hours)

Time-course of plasma peroxiredoxin-4 concentrations on day 2 of the exercise and control trials.

Homeostasis model assessment of insulin resistance (HOMA-IR)Fasting (Plasma samples will be collected at 0 (fasted) hours)

Homeostasis model assessment of insulin resistance (HOMA-IR) on day 2 of the exercise and control trials using fasting glucose and insulin concentrations.

C-reactive protein concentration8 hours (Plasma samples will be collected at 0 (fasted), 2, 5, 8 hours)

Time-course of plasma C-reactive protein concentrations on day 2 of the exercise and control trials.

Glucose concentration8 hours (Plasma samples will be collected at 0 (fasted), 0.25, 0.5, 1, 2, 3, 4, 4.25, 4.5, 5, 6, 7, 8 hours)

Time-course of plasma glucose concentrations on day 2 of the exercise and control trials.

Insulin concentration8 hours (Plasma samples will be collected at 0 (fasted), 0.5, 1, 3, 4, 4.5, 6, 8 hours)

Time-course of plasma insulin concentrations on day 2 of the exercise and control trials.

Non-esterified fatty acids concentration8 hours (Plasma samples will be collected at 0 (fasted), 0.5, 1, 3, 4, 4.5, 6, 8 hours)

Time-course of plasma non-esterified fatty acid concentrations on day 2 of the exercise and control trials.

Total cholesterol concentrationFasting (Plasma samples will be collected at 0 (fasted) hours)

Circulating concentrations of plasma total cholesterol in the fasted state on day 2 of the exercise and control trials.

Low-density lipoprotein cholesterol concentrationFasting (Plasma samples will be collected at 0 (fasted) hours)

Circulating concentrations of plasma low-density lipoprotein cholesterol in the fasted state on day 2 of the exercise and control trials.

Interleukin-6 concentration8 hours (Plasma samples will be collected at 0 (fasted), 2, 5, 8 hours)

Time-course of plasma interleukin-6 concentrations on day 2 of the exercise and control trials.

Interleukin-10 concentration8 hours (Plasma samples will be collected at 0 (fasted), 2, 5, 8 hours)

Time-course of plasma interleukin-10 concentrations on day 2 of the exercise and control trials.

Tumor necrosis factor alpha concentration8 hours (Plasma samples will be collected at 0 (fasted), 2, 5, 8 hours)

Time-course of plasma tumor necrosis factor alpha concentrations on day 2 of the exercise and control trials.

Superoxide dismutase 3 concentration8 hours (Plasma samples will be collected at 0 (fasted), 2, 5, 8 hours)

Time-course of plasma superoxide dismutase 3 concentrations on day 2 of the exercise and control trials.

Systolic and diastolic blood pressure8 hours (Blood pressure will be measured at 0 (fasted), 1, 2, 3, 4, 5, 6, 7, 8 hours)

Time-course of systolic and diastolic blood pressure on day 2 of the exercise and control trials.

Trial Locations

Locations (1)

Loughborough University

🇬🇧

Loughborough, Leicestershire, United Kingdom

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