Determining the association between gender-related factors and the perception of exertional dyspnoea in healthy males and females

The perception exertional dyspnoea is greater in females than males at absolute, but not relative, levels of minute ventilation (VE). The mechanisms of sex differences in exertional dyspnoea are unclear, but since dyspnoea perception is influenced by psychological, social, and cultural factors, it is possible that gender-related characteristics confound the assessment of sex differences in exertional dyspnoea. We sought to determine the association between gender-related characteristics and dyspnoea during exercise in males and females. Forty-six healthy adults (n=22 males, n=24 females) completed the Stanford Gender-related Variables for Health Research questionnaire to assess their gender-related characteristics (i.e., caregiver strain, work strain, independence, risk-taking, emotional intelligence, social support, and discrimination), spirometry, and an incremental cycle exercise test. Throughout exercise, standard cardiorespiratory parameters were monitored, and dyspnoea perception was assessed using the Borg scale. Females had significantly higher scores than males for emotional intelligence (p=0.029) and social support (p=0.049); whereas other gender-related characteristics were similar between the sexes (all p>0.05). Females reported significantly higher dyspnoea intensity and unpleasantness ratings than males at a V̇E of 80 l·min-1 (both p<0.05); however, males had higher dyspnoea intensity ratings at 20 and 40 % of maximum voluntary ventilation (MVV; both p<0.05). After adjusting for sex, height, body mass, and age, emotional intelligence was significantly associated with dyspnoea intensity at a V̇E of 50 l·min-1 and 50 %MVV (R2=0.14-0.18, all p<0.05). Our findings suggest that gender-related characteristics influence the perception of exertional dyspnoea, and may confound the assessment of sex differences in exertional dyspnoea perception.