Weight loss reduces dyspnea on exertion in obese women

During submaximal exercise, some otherwise healthy obese women experience breathlessness, or dyspnea on exertion (+DOE), while others have mild or no DOE (-DOE). We investigated whether weight loss could reduce DOE. Twenty nine obese women were grouped based on their Ratings of Perceived Breathlessness (RPB) during constant load 60W cycling: +DOE (n=14, RPB≥4, 34±8 years, and 36±3kg/m²) and -DOE (n=15, RPB≤2, 32±8 years, and 36±4kg/m²) and then completed a 12-week weight loss program. Both groups lost a moderate amount of weight (+DOE: 6.6±2.4kg, -DOE: 8.4±3.5kg, and p<0.001). RPB decreased significantly in the +DOE group (from 4.7±1.1 to 3.1±1.6) and remained low in the -DOE (from 1.5±0.7 to 1.6±1.1) (interaction p<0.002). Most physiological variables measured (i.e. body composition, fat distribution, pulmonary function, oxygen cost of breathing, and cardiorespiratory measures) improved with weight loss; however, the decrease in RPB was not correlated with any of these variables (p>0.05). In conclusion, moderate weight loss was effective in reducing breathlessness on exertion in obese women who experienced DOE at baseline.