The modified Medical Research Council scale for the assessment of dyspnea in daily living in obesity: a pilot study

Forty-five obese subjects (17 M/28 F, BMI: 43？±？9 kg/m2) were included in this pilot study. Dyspnea in daily living was evaluated by the mMRC scale and exertional dyspnea was evaluated by the Borg scale after 6MWT. Pulmonary function tests included spirometry, plethysmography, diffusing capacity of carbon monoxide and arterial blood gases. Fasting blood glucose, total cholesterol, triglyceride, N-terminal pro brain natriuretic peptide, C-reactive protein and hemoglobin levels were analyzed.Eighty-four percent of patients had a mMRC？≥？1 and 40% a mMRC？≥？2. Compared to subjects with no dyspnea (mMRC？=？0), a mMRC？≥？1 was associated with a higher BMI (44？±？9 vs 36？±？5 kg/m2, p？=？0.01), and a lower expiratory reserve volume (ERV) (50？±？31 vs 91？±？32%, p？=？0.004), forced expiratory volume in one second (FEV1) (86？±？17 vs 101？±？16%, p？=？0.04) and distance covered in 6MWT (401？±？107 vs 524？±？72 m, p？=？0.007). A mMRC？≥？2 was associated with a higher Borg score after the 6MWT (4.7？±？2.5 vs 6.5？±？1.5, p？<？0.05).This study confirms that dyspnea is very frequent in obese subjects. The differences between the “dyspneic” and the “non dyspneic” groups assessed by the mMRC scale for BMI, ERV, FEV1 and distance covered in 6MWT suggests that the mMRC scale might be an useful and easy-to-use tool to assess dyspnea in daily living in obese subjects.Obesity, defined as a Body Mass Index (BMI) greater than or equal to 30 kg/m2, is a significant public health concern. According to the World Health Organization, worldwide obesity has more than doubled since 1980 and in 2008 there were about 1.5 billion overweight adults (25？≤？BMI？<？30 kg/m2). Of these, over 200 million men and nearly 300 million women were obese [1].Dyspnea is very frequent in obese subjects. In a large epidemiological study, 80% of obese patients reported dyspnea after climbing two flights of stairs [2]. In a series of patients with morbid obesity, Collet et al. found that patients with a BMI？>？49 kg/m2 had more severe dys