Lactate and pyruvate changes during treadmill exercise in patients with intermittent claudication

Area of Science:

• Exercise physiology
• Vascular medicine
• Metabolic studies

Background:

• Intermittent claudication is characterized by exercise-induced leg pain due to peripheral arterial disease.
• Understanding leg muscle metabolism during exercise is crucial for diagnosing and managing this condition.
• Previous methods for assessing anaerobic metabolism during exercise have limitations.

Purpose of the Study:

• To investigate exercise and post-exercise leg muscle metabolism in healthy individuals and patients with intermittent claudication.
• To evaluate the utility of regional catheterization for studying metabolic changes during and after treadmill exercise.
• To compare lactate and pyruvate concentrations in arterial and popliteal venous blood.

Main Methods:

• Regional catheterization of the popliteal vein in 6 healthy controls and 34 patients with intermittent claudication.
• Exhaustive constant load treadmill exercise.
• Intermittent blood sampling during and after exercise.
• Analysis of lactate and pyruvate concentrations in arterial and popliteal venous blood.

Main Results:

• Arterial pyruvate increased less than lactate during exercise in both groups.
• Patients showed a continuous rise in arterial pyruvate post-exercise, unlike controls.
• The arterio-popliteal lactate difference was significantly higher in patients during exercise.
• Patients exhibited a higher lactate-pyruvate ratio in popliteal venous blood compared to arterial blood.

Conclusions:

• Regional catheterization is an effective technique for studying anaerobic work onset and degree.
• This method allows for the assessment of spontaneous and reactive metabolic changes in leg muscles.
• The findings highlight differences in leg muscle metabolism during exercise in intermittent claudication patients.