Respiratory centre sensitivity and exercise tolerance in healthy Thais

Area of Science:

• Respiratory Physiology
• Exercise Science
• Gerontology

Background:

• Understanding normal respiratory function and exercise capacity is crucial for assessing health across different age groups.
• Previous research has not fully elucidated age-related changes in respiratory center sensitivity and exercise tolerance specifically within the Thai population.

Purpose of the Study:

• To establish normal ranges for respiratory center sensitivity and exercise tolerance in healthy Thai individuals.
• To investigate age- and sex-related differences in these physiological parameters.

Main Methods:

• Sixty-nine healthy Thai subjects (18-72 years) underwent tests including ventilatory drive, ventilatory response to CO2, musculo-ventilation transfer, and a two-minute walking test.
• Breathing sensation was rated using a visual analogue scale.

Main Results:

• Elderly subjects demonstrated higher end-tidal PCO2 and tidal volume response to CO2, alongside reduced exercise tolerance compared to younger individuals.
• Young males showed a higher ventilatory response to CO2 than young females.
• Increased airway resistance, rather than blunted respiratory center sensitivity, was identified as a primary contributor to hypoventilation and exercise limitation in the elderly.

Conclusions:

• Age-related declines in exercise tolerance in Thais are mainly attributed to defective respiratory apparatus, specifically increased airway resistance.
• The observed high tidal volume response to CO2 in the elderly appears insufficient for maintaining adequate ventilation.
• Further research is needed to understand the lower ventilatory response in Thais compared to other populations.