Obesity is associated with higher heart rate and excessive dyspnea with fatigue in the six-minute walk test.

According to the World Health Organization, obesity is the fifth most important risk factor responsible for cardiovascular mortality. The Six- Minute Walk Test (6MWT) is a very useful assessment of patients' exercise tolerance in clinical circumstances. Owing to submaximal exercise during the test, its results reflect patients' ability to perform daily activities. AIM: Assessment of cardiorespiratory functions in obese patients using the 6MWT. MATERIALS AND METHODS: The study group included 234 patients, divided into 3 groups depending on their BMI: Group 1 - BMI<30kg/m2, Group 2 - BMI≥30<40kg/m2, Group 3 - BMI≥40kg/m2. Laboratory tests were performed for all patients. Cardiorespiratory fitness was assessed with the 6MWT. Pulse rate, blood pressure (BP) and oxygen saturation, the degree of dyspnea and perceived exertion, the total distance walked, and the percent of the predicted mean value for the walked distance were recorded and analyzed. RESULTS: Pre and post the 6MWT test BP and pulse rate increased significantly with the higher BMI and were highest in Group 3. Patients with the highest BMI felt more fatigue after the test than those with the lowest BMI. Patients in Group 1 walked a significantly longer total distance compared to Group 3, However, a significantly higher pulse rate and degree of dyspnea and exertion were observed in more obese patients. CONCLUSIONS: Morbidly obese patients covered the same walking distance as adjusted according to Enright's reference equations in the 6MWT as patients with a lower BMI. They required more effort as evidenced by the increased pulse rate and BP, and they complained of a higher degree of dyspnea and perceived exertion. Resting higher heart rates in this patient group may be an issue of concern in the context of subsequent morbidity and all-cause mortality.

The Impact of Obesity on Nighttime Blood Pressure Dipping.

Background and objectives: It is commonly known that obesity not only increases arterial hypertension (HT) risk but also impacts on the response to antihypertensives. This study aimed to assess blood pressure (BP) parameters based on Ambulatory Blood Pressure Measurement (ABPM) in obese patients. Materials and Methods: The study group consisted of 128 patients with obesity (BMI ≥ 30 kg/m2), with an average age of 43.25 years (±12.42), including 55 males and 73 females. They were divided into 2 groups: 1-with BMI ≥ 30 kg/m2 and <40 kg/m2, 2-with BMI ≥ 40 kg/m2. Each patient underwent 24-h blood pressure monitoring. The average 24-h, daytime and nighttime systolic and diastolic pressure, as well as 24-h mean heart rate and % of nocturnal dip, were assessed. Results: Mean BMI in group 1 was 34.73 kg/m2 (±2.96), and in group 2 it was 47.6 kg/m2 (±6.3). Group 1 was significantly older than group 2 (46.5 vs. 39 years old). The analysis of ABPM revealed significantly higher BP values in all measurements in group 2 (i.e., systolic blood pressure (SBP) 24 h median = 132 mmHg; diastolic blood pressure (DBP) 24 h median = 84 mmHg). The nocturnal dip was greater in group 1 (8.95%). Mean 24-h heart rate was also higher in group 2 (median = 76 beats/min) than group 1 (median = 67.5 beats/min). More than half of patients in group 2 had been previously treated for HT, and based on ABPM, new HT was diagnosed in 6 patients from group 1 and 14 patients from group 2. Three groups of patients were identified based on nighttime dip: dipper, non-dipper, and reverse-dipper. No patient of the extreme dipper type was found. Group 2 comprised of significantly more patients of the reverse-dipper type. Conclusions: Patients with extreme morbid obesity frequently exhibit HT of the reverse-dipping pattern. This type is often linked with a higher risk of more advanced cardiovascular illness.