Respiratory Muscle Strength and Quality of Life in Patients With Heart Failure and Their Main Correlated Factors: A Cross-sectional Study.

BACKGROUND: Heart failure may cause peripheral and respiratory muscle alterations, dyspnea, fatigue, and exercise intolerance, worsening the quality of life of patients. OBJECTIVES: The aims of this study were to analyze respiratory muscle strength and quality of life of patients with heart failure and correlate them with clinical variables and functional classification. METHODS: This cross-sectional study involved patients with heart failure. A manovacuometer assessed maximum inspiratory and expiratory pressures, and quality of life was assessed using the Minnesota Living with Heart Failure Questionnaire. Functional classification was categorized according to the New York Heart Association (NYHA) class in I, II, III, or IV. RESULTS: We included 60 patients (66.7% male) with a mean age of 62.0 years and mean left ventricular ejection fraction of 42.0%. Maximum inspiratory pressure and maximum expiratory pressure were close to normal (>70% of predicted) in most patients; however, a subgroup composed mostly of patients with dilated heart failure and NYHA class III (n = 21) presented low maximum inspiratory pressure values (59.2%; 95% confidence interval, 55.7%-62.8%). The mean total score of the Minnesota Living with Heart Failure Questionnaire was 44.4 points, being negatively correlated with left ventricular ejection fraction (r = -0.29, P = .02). Patients with NYHA class III and disease duration longer than 120 months presented higher total (P < .01) and physical dimension scores. CONCLUSIONS: Most patients had respiratory muscle strength close to normal; however, those with dilated heart failure and NYHA class III presented low maximum inspiratory pressure values. Quality of life was moderately compromised, mainly because of long disease duration, NYHA class III, and low left ventricular ejection fraction.

Analysis of respiratory muscle strength and its relationship with functional capacity between different field tests in patients with heart failure.

OBJECTIVE: To analyze respiratory muscle strength of patients with heart failure (HF) and correlate with functional capacity. METHODS: This cross-sectional study involved patients with compensated HF of both sexes, aged above 18 years. Respiratory muscle strength was assessed by measuring maximum inspiratory (MIP) and expiratory pressures (MEP) using a manovacuometer. Patients were randomized into two groups to assess functional capacity: six-minute walk test (6MWT) and incremental shuttle walk test (ISWT). RESULTS: Forty-eight patients were evaluated (23 from 6MWT and 25 from ISWT group). Most were male (67.8%), with mean age of 62.3 years and left ventricular ejection fraction of 40.8%. Mean predicted values of MIP [81.2% (74.7-87.8%)] and MEP [95.6% (88.2-103.0%)] did not indicate respiratory muscle weakness. The higher the New York Heart Association (NYHA) functional class, the lower the MIP (p = .011) and MEP (p = .016) values. Physically active patients presented higher respiratory muscle strength than those sedentary (MIP: 104.5 vs. 71.9 cmH2O, p < .001; MEP: 120.0 vs. 91.1 cmH2O, p = .004). Functional capacity was impaired [6MWT: 416.0 m (372.8-459.3 m); ISWT: 304 m (263.4-344.9 m)], and distance covered in the ISWT was shorter than 6MWT group (p < .001). Distance covered in the ISWT group presented a moderate positive correlation with MIP (r = 0.45; p = .022) and MEP (r = 0.41; p = .041). CONCLUSION: Most patients with HF presented respiratory muscle strength close to predicted values; however, sedentary patients and those with high NYHA functional class, showed reduced MIP and MEP. Functional capacity was reduced, and MIP and MEP correlated with distance covered in the ISWT.

Correlação da força muscular respiratória com medidas antropométricas e nível de atividade física em adultos da atenção primária / Correlación de la fuerza muscular respiratoria con las medidas antropométricas y el nivel de actividad física en adultos en la atención primaria / Correlation of respiratory muscle strength with anthropometric measures and physical activity level in adults in primary care

RESUMO O objetivo deste estudo foi correlacionar a força muscular respiratória com as medidas antropométricas e o nível de atividade física de indivíduos adultos da atenção primária. Trata-se de um estudo transversal, realizado em uma unidade básica de saúde, onde foram incluídos indivíduos de ambos os sexos e com idade superior a 18 anos. A força muscular respiratória foi analisada pela pressão inspiratória máxima (PImáx) e pressão expiratória máxima (PEmáx), por meio do manovacuômetro, onde valores pressóricos acima de 80% em relação ao predito foram considerados normais. Utilizou-se balança mecânica, estadiômetro e fita métrica para mensuração das principais medidas antropométricas: índice de massa corporal (IMC), circunferência de pescoço (CP), circunferência abdominal (CA), circunferência de quadril (CQ), relação cintura-quadril (RCQ) e o índice de adiposidade corporal (IAC). O nível de atividade física foi determinado pelo questionário internacional de atividade física (IPAQ), onde os indivíduos foram categorizados como sedentário, irregularmente ativo A, irregularmente ativo B, ativo ou muito ativo, sendo realizada também a estimativa dos equivalentes metabólicos (MET) alcançados. Foram avaliados 110 indivíduos adultos (78,1% do sexo feminino; 51,9±12,3 anos), e com porcentagem em relação ao predito (%) de PImáx de 96,3±32,4% e 98,9±27,3% de PEmáx. A %PImáx apresentou fraca correlação com o IAC (r=0,23; p=0,01) e com a CQ (r=0,20; p=0,03), e a %PEmáx com o IMC (r=0,26; p<0,01) e IAC (r=0,30; p<0,01). Não houve diferença dos valores médios de %PImáx (p=0,61) e %PEmáx (p=0,54) entre as categorias do IPAQ, além de não existirem correlações (p>0,05) com os MET estimados. Em adultos da atenção primária, a força muscular respiratória apresentou fraca correlação com IMC, CQ e IAC, porém sem correlação com o nível de atividade física.

RESUMEN El objetivo de este estudio fue correlacionar la fuerza muscular respiratoria con las medidas antropométricas y el nivel de actividad física de individuos adultos en atención primaria. Este es un estudio transversal, realizado con personas de ambos los sexos y mayores de 18 años en una unidad básica de salud. Se evaluó la presión inspiratoria máxima (PImáx.) y la presión espiratoria máxima (PEmáx.) de la fuerza muscular respiratoria mediante un manovacuómetro, en el que se consideraron normales los valores de presión superiores al 80% en relación al valor predicho. Se utilizó una balanza mecánica, estadiómetro y cinta métrica para obtener las principales medidas antropométricas: índice de masa corporal (IMC), circunferencia del cuello (CC), circunferencia abdominal (CA), circunferencia de la cadera (CCA), relación cintura-cadera (RCCA) y el índice de adiposidad corporal (IAC). El nivel de actividad física fue determinado por el Cuestionario internacional de actividad física (IPAQ), que clasifica a los individuos como sedentarios, irregularmente activos A, irregularmente activos B, activos o muy activos, y también se estimó los equivalentes metabólicos alcanzados (MET). Se evaluaron 110 individuos adultos (78,1% mujeres; 51,9±12,3 años), y con un porcentaje en relación al predicho (%) de PImáx. de 96,3±32,4% y de PEmáx de 98,9±27,3%. El %PImáx. mostró una correlación débil con el IAC (r=0,23; p=0,01) y con el CCA (r=0,20; p=0,03), y el %PEmáx. con el IMC (r=0,26; p<0,01) e IAC (r=0,30; p<0,01). No hubo diferencia en los valores medios de %PImáx. (p=0,61) y %PEmáx. (p=0,54) entre las categorías de IPAQ, además de que no existen correlaciones (p>0,05) con los MET estimados. En los adultos en la atención primaria, la fuerza muscular respiratoria mostró una correlación débil con el IMC, CCA e IAC, pero sin correlación con el nivel de actividad física.

ABSTRACT This study aimed to correlate respiratory muscle strength with anthropometric measures and physical activity level in adults in primary care. This cross-sectional study was conducted in a basic health unit with individuals of both genders aged 18 years or older. Respiratory muscle strength was analyzed by maximal inspiratory (MIP) and expiratory (MEP) pressures using a manovacuometer. Values above 80% of the predicted were considered normal. Anthropometric data was obtained using a mechanical scale, stadiometer, and measuring tape, namely: body mass index (BMI); neck (NC), waist (WC), and hip (HC) circumference; waist-to-hip ratio (WHR), and body adiposity index (BAI). Physical activity level was determined by the international physical activity questionnaire (IPAQ), where individuals were categorized into sedentary, irregularly active A, irregularly active B, active, or very active. The instrument also estimated the achieved metabolic equivalents (MET). Our study sample comprised 110 adults (78.1% female; 51.9±12.3 years) with 96.3 ± 32.4% MIP and 98.9 ± 27.3 % MEP in relation to the predicted. The %MIP showed a weak correlation with BAI (r=0.23; p=0.01) and HC (r=0.20; p=0.03), and %MEP with BMI (r=0.26; p<0, 01) and BAI (r=0.30; p<0.01). We verified no difference between the average %MIP (p=0.61) and %MEP (p=0.54) within the IPAQ categories and no correlations (p> 0.05) with the estimated MET. Respiratory muscle strength of adults in primary care showed a weak correlation with BMI, HC, and BAI, and no correlation with physical activity level.