心衰竭病人身體質量指數與疾病預後之探討

Cardiac Event-Free Survival among Heart Failure Patients in Different Body Mass Index Groups

黃翠媛(Tsuey‐Yuan Huang) ； 黃秀梨(Shiow‐Li Hwang)

《護理暨健康照護研究》 9卷2期 (2013/06) Pp. 106-115

https://doi.org/10.6225/JNHR.09.2.106

摘要

Background: Obesity is a risk factor for cardiovascular diseases and a confirmed cause of ischemic heart disease, hypertension, and atherosclerosis, all of which are predisposing factors of heart failure (HF). HF and various other chronic diseases can also induce systemic inflammation response syndrome. This inflammatory condition causes poor nutritional status, cachexia, and unfavorable disease prognoses. However, this obesity paradox has not been verified in Asian populations. Clarifying the effect of obesity on HF prognoses can help healthcare professionals improve HF patient nutritional care. Purpose: The purpose of this study was to monitor and compare disparities in heart‐related events (e.g., unscheduled medical visits, hospitalization, and death) over a 12‐month period among an HF patient population with varying body masses. Methods: This study adopted a prospective long‐term follow‐up research method. The 125 participants were symptomatic patients diagnosed with chronic heart failure (CHF) based on echocardiography results. Patient height, weight, and disease data were measured and monthly telephone interviews were conducted with each patient for 12 months in order to understand the nature of their inpatient and unscheduled outpatient visits. Patients were assigned into 3 body mass index (BMI) groups, including obese (30 to 45 kg/m^2), overweight (25 to 29.9 kg/m^2), and normal/underweight (17 to 24.9 kg/m^2) groups. Prognosis results for the 3 groups were compared and data were entered into SPSS software. The Kaplan‐Meier survival curve then examined participant disease outcomes. Results: Possible predictors correlated to survival included age (65‐year‐old group), left ventricular ejection fraction (LVEF; 40% group), HF classifications announced by the New York Heart Association (NYHA Class III/IV vs. Class I/II), and BMI. Log‐rank test results suggested that patients who had an LVEF lower than 40% (350.8 ± 18.6 vs. 508.3 ± 46.6 d, p = .001), were diagnosed with NYHA‐based Class III/IV HF (326.6 ± 23.2 vs. 496.6 ± 42.4 days, p ＜ .001), or had a BMI in the normal/underweight range (371.3 ± 18.8 d) had a relatively shorter life expectancy and higher mortality risk. Results further indicated that, overall, BMI caused significant differences among group outcomes (p for log‐rank test = .006 with 2 df). Post‐hoc test results suggested that life expectancy for normal/underweight group participants was shorter than for overweight and obese group participants (p for normal/underweight vs. overweight = .008; p for normal/underweight vs. obese = .044). Conclusion / Practical Implications: Disease prognoses for normal and underweight HF patients were unfavorable compared to those of overweight patients. In other words, hospitalizations and deaths of normal and underweight HF patients occurred earlier. This study recommends that clinical practitioners dismiss the stereotype that obesity only negatively impacts the cardiovascular system, as our results indicate that reducing or maintaining body mass may not benefit HF patient prognoses.

關鍵字

慢性心衰竭 ； 身體質量指數 ； 再住院率 ； 存活分析

並列摘要

Background: Obesity is a risk factor for cardiovascular diseases and a confirmed cause of ischemic heart disease, hypertension, and atherosclerosis, all of which are predisposing factors of heart failure (HF). HF and various other chronic diseases can also induce systemic inflammation response syndrome. This inflammatory condition causes poor nutritional status, cachexia, and unfavorable disease prognoses. However, this obesity paradox has not been verified in Asian populations. Clarifying the effect of obesity on HF prognoses can help healthcare professionals improve HF patient nutritional care. Purpose: The purpose of this study was to monitor and compare disparities in heart‐related events (e.g., unscheduled medical visits, hospitalization, and death) over a 12‐month period among an HF patient population with varying body masses. Methods: This study adopted a prospective long‐term follow‐up research method. The 125 participants were symptomatic patients diagnosed with chronic heart failure (CHF) based on echocardiography results. Patient height, weight, and disease data were measured and monthly telephone interviews were conducted with each patient for 12 months in order to understand the nature of their inpatient and unscheduled outpatient visits. Patients were assigned into 3 body mass index (BMI) groups, including obese (30 to 45 kg/m^2), overweight (25 to 29.9 kg/m^2), and normal/underweight (17 to 24.9 kg/m^2) groups. Prognosis results for the 3 groups were compared and data were entered into SPSS software. The Kaplan‐Meier survival curve then examined participant disease outcomes. Results: Possible predictors correlated to survival included age (65‐year‐old group), left ventricular ejection fraction (LVEF; 40% group), HF classifications announced by the New York Heart Association (NYHA Class III/IV vs. Class I/II), and BMI. Log‐rank test results suggested that patients who had an LVEF lower than 40% (350.8 ± 18.6 vs. 508.3 ± 46.6 d, p = .001), were diagnosed with NYHA‐based Class III/IV HF (326.6 ± 23.2 vs. 496.6 ± 42.4 days, p ＜ .001), or had a BMI in the normal/underweight range (371.3 ± 18.8 d) had a relatively shorter life expectancy and higher mortality risk. Results further indicated that, overall, BMI caused significant differences among group outcomes (p for log‐rank test = .006 with 2 df). Post‐hoc test results suggested that life expectancy for normal/underweight group participants was shorter than for overweight and obese group participants (p for normal/underweight vs. overweight = .008; p for normal/underweight vs. obese = .044). Conclusion / Practical Implications: Disease prognoses for normal and underweight HF patients were unfavorable compared to those of overweight patients. In other words, hospitalizations and deaths of normal and underweight HF patients occurred earlier. This study recommends that clinical practitioners dismiss the stereotype that obesity only negatively impacts the cardiovascular system, as our results indicate that reducing or maintaining body mass may not benefit HF patient prognoses.

並列關鍵字

chronic heart failure ； body mass index ； re‐hospitalization ； survival analysis

參考文獻

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