Exercise and Coronary Heart Disease Risk Markers in Male Smokers and Non-Smokers
Condition: Cigarette Smoking; Coronary Heart Disease; Cardiovascular Risk Factor; Insulin Resistance; Oxidative Stress; Inflammation
MeSH terms: Heart Diseases; Coronary Disease; Coronary Artery Disease; Myocardial Ischemia; Insulin Resistance; Inflammation
Study type: Interventional

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.
    

Intervention name(s): Exercise
Intervention type(s): Behavioral
Intervention description(s): 60 min treadmill exercise performed at 60% of maximum oxygen uptake.
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: Coronary heart disease; Exercise; Inflammation; Postprandial lipaemia; Smoking