Cardiorespiratory fitness as a mediator in the relationship between lung function and blood pressure in adults

It is unclear whether physical activity and cardiorespiratory fitness (CRF) are pathways that link low pulmonary function (LPF) to increased blood pressure (BP). Therefore, we investigated the extent to which CRF and moderate-to-vigorous physical activity (MVPA) mediate the relationship between LPF and high BP in adults. We conducted a cross-sectional study with 1,362 participants that underwent cardiopulmonary exercise testing (CPET), spirometry, and wore an accelerometer to determine physical activity patterns. We performed mediation analyses using structural equations considering peak oxygen uptake (V̇O2) and MVPA as mediators, forced vital capacity (FVC) and forced expiratory volume in the first second (FEV1) as independent variables, and systolic and diastolic blood pressure (SBP, DBP) as dependent variables. The probability of alpha error was set at 5%. We found a significant total effect of FVC on SBP and DBP considering V̇O2 as mediator (P<0.01). Indirect effects were also significant, with 42.6% of the total effect of FVC on SBP and 77% on DBP mediated by V̇O2 (P<0.01). We did not observe a direct effect of FVC on SBP and DBP. Considering FEV1 as an independent variable, the total effect on SBP was also significant, as were the indirect effects, mediated by V̇O2 at 14.8% for SBP and 7.6% for DBP (P<0.01). We did not find an indirect effect of FVC or FEV1 considering the MVPA as a mediator. CRF mediates the pathway that links LPF and elevated BP. Therefore, CRF is more sensitive to variations in FVC and FEV1 than MVPA.

Anthropometric midarm measurements can detect systemic fat-free mass depletion in patients with chronic obstructive pulmonary disease

Our objective was to determine whether anthropometric measurements of the midarm (MA) could identify subjects with whole body fat-free mass (FFM) depletion. Fifty-five patients (31 percent females; age: 64.6 ± 9.3 years) with mild/very severe chronic obstructive pulmonary disease (COPD), 18 smokers without COPD (39 percent females; age: 49.0 ± 7.3 years) and 23 never smoked controls (57 percent females; age: 48.2 ± 9.6 years) were evaluated. Spirometry, muscle strength and MA circumference were measured. MA muscle area was estimated by anthropometry and MA cross-sectional area by computerized tomography (CT) scan. Bioelectrical impedance was used as the reference method for FFM. MA circumference and MA muscle area correlated with FFM and biceps and triceps strength. Receiver operating characteristic curve analysis showed that MA circumference and MA muscle area cut-off points presented sensitivity and specificity >82 percent to discriminate FFM-depleted subjects. CT scan measurements did not provide improved sensitivity or specificity. For all groups, there was no significant statistical difference between MA muscle area [35.2 (29.3-45.0) cm²] and MA cross-sectional area values [36.4 (28.5-43.3) cm²] and the linear correlation coefficient between tests was r = 0.77 (P < 0.001). However, Bland-Altman plots revealed wide 95 percent limits of agreement (-14.7 to 15.0 cm²) between anthropometric and CT scan measurements. Anthropometric MA measurements may provide useful information for identifying subjects with whole body FFM depletion. This is a low-cost technique and can be used in a wider patient population to identify those likely to benefit from a complete body composition evaluation.

Three-year follow-up study of respiratory and systemic manifestations of chronic obstructive pulmonary disease

Few studies show patient outcomes over time in chronic obstructive pulmonary disease (COPD). In the present study, we monitored forced expiratory volume in the first second (FEV1) and other manifestations of the disease over 3 years in 133 COPD patients (69 percent males, age = 65 ± 9 years, FEV1 = 59 ± 25 percent) evaluated at baseline. During follow-up, 15 patients (11 percent) died and 23 (17 percent) dropped out. Measurements for 95 (72 percent) COPD patients alive after 3 years were analyzed. FEV1, body mass index (BMI), 6-min walking distance (6MWD), Medical Research Council scale (MRC), Saint George’s Respiratory Questionnaire (SGRQ), Charlson Comorbidity index, and BODE index were obtained at baseline and after 3 years. At baseline, 17 patients (18 percent) presented mild, 39 percent moderate, 19 percent severe, and 24 percent very severe COPD. Predicted FEV1 percent and BMI did not change over the period (P > 0.05). FEV1 in liters [1.25 (0.96-1.72) vs 1.26 (0.88-1.60) L; P < 0.001], 6MWD (438 ± 86 vs 412 ± 100 m; P < 0.001), MRC [1 (1-2) vs 2 (1-3); P = 0.002], Charlson index [3 (3-4) vs4 (3-5); P = 0.009], BODE index (2.2 ± 1.8 vs 2.6 ± 2.3; P = 0.008), and total SGRQ (42 ± 19 vs 44 ± 19 percent; P = 0.041) worsened after 3 years compared to baseline measurements. These data show that COPD patients deteriorated during the 3-year follow-up despite the fact that they had only minor modifications in airway obstruction and body composition. They support the need for comprehensive patient assessment to better identify disease progression.

The six-minute walk test and body weight-walk distance product in healthy Brazilian subjects

We assessed the 6-min walk distance (6MWD) and body weight x distance product (6MWw) in healthy Brazilian subjects and compared measured 6MWD with values predicted in five reference equations developed for other populations. Anthropometry, spirometry, reported physical activity, and two walk tests in a 30-m corridor were evaluated in 134 subjects (73 females, 13-84 years). Mean 6MWD and 6MWw were significantly greater in males than in females (622 ± 80 m, 46,322 ± 10,539 kg.m vs 551 ± 71 m, 36,356 ± 8,289 kg.m, P < 0.05). Four equations significantly overestimated measured 6MWD (range, 32 ± 71 to 137 ± 74 m; P < 0.001), and one significantly underestimated it (-36 ± 86 m; P < 0.001). 6MWD significantly correlated with age (r = -0.39), height (r = 0.44), body mass index (r = -0.24), and reported physical activity (r = 0.25). 6MWw significantly correlated with age (r = -0.21), height (r = 0.66) and reported physical activity (r = 0.25). The reference equation devised for walk distance was 6MWDm = 622.461 - (1.846 x Ageyears) + (61.503 x Gendermales = 1; females = 0); r2 = 0.300. In an additional group of 85 subjects prospectively studied, the difference between measured and the 6MWD predicted with the equation proposed here was not significant (-3 ± 68 m; P = 0.938). The measured 6MWD represented 99.6 ± 11.9 percent of the predicted value. We conclude that 6MWD and 6MWw variances were adequately explained by demographic and anthropometric attributes. This reference equation is probably most appropriate for evaluating the exercise capacity of Brazilian patients with chronic diseases.

Effect of three exercise programs on patients with chronic obstructive pulmonary disease

We compared the effect of three different exercise programs on patients with chronic obstructive pulmonary disease including strength training at 50_80 percent of one-repetition maximum (1-RM) (ST; N = 11), low-intensity general training (LGT; N = 13), or combined training groups (CT; N = 11). Body composition, muscle strength, treadmill endurance test (TEnd), 6-min walk test (6MWT), Saint George's Respiratory Questionnaire (SGRQ), and baseline dyspnea (BDI) were assessed prior to and after the training programs (12 weeks). The training modalities showed similar improvements (P > 0.05) in SGRQ-total (ST = 13 ± 14 percent; CT = 12 ± 14 percent; LGT = 11 ± 10 percent), BDI (ST = 1.8 ± 4; CT = 1.8 ± 3; LGT = 1 ± 2), 6MWT (ST = 43 ± 51 m; CT = 48 ± 50 m; LGT = 31 ± 75 m), and TEnd (ST = 11 ± 20 min; CT = 11 ± 11 min; LGT = 7 ± 5 min). In the ST and CT groups, an additional improvement in 1-RM values was shown (P < 0.05) compared to the LGT group (ST = 10 ± 6 to 57 ± 36 kg; CT = 6 ± 2 to 38 ± 16 kg; LGT = 1 ± 2 to 16 ± 12 kg). The addition of strength training to our current training program increased muscle strength; however, it produced no additional improvement in walking endurance, dyspnea or quality of life. A simple combined training program provides benefits without increasing the duration of the training sessions.

Relationship between disease severity and quality of life in patients with chronic obstructive pulmonary disease

Few studies have evaluated the relationship between Airways Questionnaire 20 (AQ20), a measure of the quality of life, scores and physiological outcomes or with systemic markers of disease in patients with chronic obstructive pulmonary disease (COPD). The aim of the present study was to investigate the relationship of forced expiratory volume in 1 s (FEV1), body mass index, fat-free mass index, 6-min walk test (6MWT) results, dyspnea sensation and peripheral oxygen saturation (SpO2) with the quality of life of COPD patients. Ninety-nine patients with COPD (mean age: 64.2 ± 9.2 years; mean FEV1: 60.4 ± 25.2 percent of predicted) were evaluated using spirometry, body composition measurement and the 6MWT. The baseline dyspnea index (BDI) and the Modified Medical Research Council (MMRC) scale were used to quantify dyspnea. Quality of life was assessed using the AQ20 and the St. George's Respiratory Questionnaire (SGRQ). The Charlson index was used to determine comorbidity. The body mass index/airflow obstruction/dyspnea/exercise capacity (BODE) index was also calculated. AQ20 and SGRQ scores correlated significantly with FEV1, SpO2, 6MWT, MMRC and BDI values as did with BODE index. In the multivariate analyses, MMRC or BDI were identified as predictors of AQ20 and SGRQ scores (P < 0.001 in all cases). Thus, the relationship between AQ20 and disease severity is similar to that described for SGRQ. Therefore, the AQ20, a simple and brief instrument, can be very useful to evaluate the general impact of disease when the time allotted for measurement of the quality of life is limited.

Déficit de hormona de crecimiento en pacientes con insuficiencia cardíaca crónica / Growth hormone deficiency in patients with chronic cardiac failure

Nine patients, aged 49 to 76 years old, 7 male, were studied. Seven had an idiopathic dilated cardiomyopathy and 2 a coronary heart disease. All had a stable cardiac failure, in functional capacity II or III and were receiving digoxin, furosemide and potassium supplements. Thyroid hormone levels, basal and exercise growth hormone and IGF-1 levels were measured and compared with reference values for American populations. Left ventricular ejection fraction was measured with an isotopic technique and nutritional status using anthropometry and indirect calorimetry. Anthropometric measures, basal and postprandial oxygen consumption were within normal limits. Thyroid hormone levels were normal. During maximal exercise, growth hormone levels were 2.56ñ4.1 ng/ml and IGF-1 levels were 0.56ñ0.61 mU/ml. These values were significantly lower than expected for age and sex. These patients with chronic cardiac failure have lower than normal growth hormone and IGF-1 levels

Estenosis tricuspídea: diagnóstico y tratamiento quirúrgico / Tricuspid stenosis: diagnosis and surgical treatment

La Estenosis Tricuspídea, es una valvulopatía poco frecuente y se ha presentado en el 1.6% de los pacientes operados de diferentes valvulopatías durante los últimos 12 años en nuestro grupo. Siempre ha existido asociada a un compromiso valvular mitral y un 56% además coexiste una lesión valvular aórtica. Debe buscarse sistemáticamente en enfermos polivalvulares, especialmente cuando hay una onda "a" del pulso venoso yugular, ritmo sinusal y crecimiento de la aurícula derecha al electrocardiograma y signos de crecimiento de la aurícula derecha en la radiografía de tórax, especialmente en ausencia de hipertensión arterial pulmonar importante. El diagnóstico se confirma al encontrar los hallazgos característicos auscultatorios, ecocardiográficos, hemodinámicos y angiográficos. El tratamiento es quirúrgico, pero conservador, evitando en lo posible el reemplazo valvular tricuspídeo