Nutritional risk and associated factors in elderly patients with congestive heart failure in a Brazilian cardiology hospital

OBJECTIVE: To identify the nutritional risk and associated factors in elderly individuals with congestive heart failure admitted to a cardiology hospital. METHODOLOGY: A cross-sectional study collecting primary data was carried out in the Heart Institute of University of Sao Paulo. Nutritional risk was assessed using the Mini Nutritional Assessment (MNA). Data regarding sample (gender, age group, functional class of heart failure) was collected from medical records prior to application of the instrument. To test the association between nutritional status evaluated by MNA and independent variables, chi-square test and logistic regression were performed. RESULTS: The study included 70 elderly individuals, 57% males and 50% between 60-69 years. Almost half of the group (43%) was classified as "at risk of malnutrition." Among these, 60% were 70 years or older (p = 0.005), categorized in functional classes III and IV (48%, p = 0.025). Almost all of the "malnourished" or "at risk of malnutrition" elderly (96%) reported at least 3 kg weight loss in the last 3 months (p=0.003), and 81% of the elderly who considered have health status worse than other elderly was malnourished (p<0.001). Positive association was found between "risk of malnutrition" or be "malnourished" and functional class III and IV of the heart failure (OR 4.76; CI 1.46-15.51; p=0.010), and at least 1 kg weight loss in the last 3 months (OR 6.17; CI 1.80-21.09; p=0.004). CONCLUSION: Most of elderly were at malnourished or at risk of malnutrition. The factors associated with nutritional risk in elderly patients with congestive heart failure (age, functional class of heart failure, recent weight loss and self-assessment of health status) should be observed during routine clinical practice.


INTRODUCTION
Advances in medicine along with fall in mortality rates have led to an increasing proportion of elderly worldwide. 1,2Biological aging is a phenomenon associated with changes in the activity of cells, tissues and organs, as well as reduced effectiveness of a number of physiological processes, rendering it hard to maintain good nutritional status.[5] Congestive heart failure (CHF) is the most frequent cause of hospitalization for cardiovascular disease, accounting for 2.6% of hospitalizations and 6% of deaths recorded by The Brazilian National Health System (SUS) in 2007.Moreover, the rate of in-hospital mortality varies with age, being higher in elderly individuals. 6ong the elderly individuals, hospitalization represents a period of marked instability and compromised nutritional status which in turn can influence morbidity and mortality rates. 7The prevalence of malnutrition in hospitals ranges from 19 to 80% in medical and surgical patients, with higher rates seen among elderly individuals. 8nce the dawn of medicine, malnutrition has been recognized as a sign associated with cardiac insufficiency, particularly in its later stages.Varying degrees of protein-calorie depletion can be observed. 9A Brazilian study in 53 patients hospitalized for CHF with a mean age of 57.7 years using Subjective Global Nutritional Assessment reported a prevalence of malnutrition of 60.4%. 10 Cardiac patients with moderate or severe calorie malnutrition were found to have twice the mortality risk.Therefore, early identification of malnourished patients or those at risk of malnutrition is essential to enable the administration of nutritional
therapy to correct nutritional changes and improve patient outcomes. 10,11e high prevalence of congestive heart failure in elderly individuals, who exhibit a tendency to reduce the body mass with the age increase, 12 and the association between malnutrition and CHF, create the need for studies aimed at early identification of nutritional risk in this population and investigation of its association with other variables, providing the rationale for the present study.

METHODOLOGY
A cross-sectional study entailing collection of primary data was carried out.All individuals aged 60 years or older participating in this study, were hospitalized in the Heart Institute of University of São Paulo, which treats patients with high complexity cardiovascular diseases between October and December 2009.
The data related to subject description (gender and age) were collected prior to application of the MNA from admission records.The diagnosis of congestive heart failure and the functional class classification was confirmed by medical notes from patient's medical records.Patients enrolled in the SUS, diagnosed with congestive heart failure on medical charts, and classified according to the proposal of The New York Heart Association (NYHA), 13 without cognitive impairment and able to understand the questions and answer them verbally, were included.
NYHA classifies the severity of clinical disease and functional limitation, as described below: • Class I: no limitation of physical activity.
Ordinary physical activity does not cause undue fatigue, palpitation, or dyspnea.
• Class II: slight limitation of physical activity.Comfortable at rest, but ordinary physical activity results in fatigue, palpitations, or dyspnea.
• Class III: marked limitation of physical activity.Comfortable at rest, but less than ordinary activity causes fatigue, palpitation, or dyspnea, or marked limitation of physical activity.Comfortable at rest, but minimal exertion causes fatigue, palpitation, or dyspnea.
• Class IV: unable to carry on any physical activity without discomfort.Symptoms of cardiac insufficiency present at rest.If any physical activity is undertaken, discomfort is increased.
Patients receiving enteral feeding, exclusively or partially, were excluded from the study.

Assessment of nutritional risk
Weight (kilograms) and height (meters) measurements were obtained using an electronic scale (Filizola ® ) coupled with a stadiometer, and performed with minimal clothing and footwear removed.For those patients whose weight and height measurements could not be taken by conventional methods, specific formulas recommended for these estimates were employed. 14,15In such cases, a clinical adipometer (Lange ® , Cambridge Scientific Industries, USA) was used to measure the extent of subscapular skinfold (millimeters).
The Mini Nutritional Assessment (MNA), 16 a screening instrument includes questions about decreased food intake, recent weight loss, conditions of mobility, psychological stress or acute disease, and neuropsychological problems as well as body mass index (BMI), was used to assess nutritional risk, with initial screening as per recommendations for the instrument.All data were collected by the same nutritionist.
After summing scores, respondents were screened for continuation with the evaluation or otherwise, where those scoring less than or equal to 11 points were classified as "possible malnutrition" cases and proceeded with the evaluation according to the methodology of the instrument. 16ter the screening process, the overall assessment of the MNA was applied to collect data on patient abode (home or geriatric institution), drug use, skin lesions or pressure sores, and nutritional information.The information on nutrition included average number of meals per day, dietary sources of protein, fruits, vegetables, liquids and self-feeding ability.In addition, participants performed a self-assessment of nutritional status and health, representing general perception about health, according to several biopsychosocial dimensions.
All patients undergoing the comprehensive MNA evaluation were measured for brachial perimeter (BP) and perimeter of the leg (PL) using an inelastic tape measure (cm), based on specific measurement techniques and suggested score for the instrument. 16e final nutritional status of patients was evaluated according to the suggested score for the MNA: patients scoring higher than 23.5 were classified as "no nutritional risk"; those with 17 to 23.5 points were "at risk of malnutrition; while those scoring less than 17 points were classified as "malnourished". 16is study was approved by the Research Ethics Committee of the Heart Institute of University of Sao Paulo (protocol number 3309/09/060) and by the Ethics Committee for analysis of research projects of Clinical Hospital of University of Sao Paulo (protocol number 0892/09).Participants were informed about the purpose of the study, its risks and the procedures involved.Subsequently, the subjects were invited to participate in the study by signing an informed consent term.

Statistical analysis
The description of the population for the distribution of the elderly individuals was expressed in absolute and relative frequencies, according to the study variables (gender and, age).To facilitate data analysis, the population was categorized into only two age groups, namely 60 to 69 years and 70 years or older, due to the small number of individuals, and the functional class into class I and II; and class III and IV, in order to group elderly with similar limitations.
The comparison of proportions was performed using the chi-square test.To test the association between nutritional status evaluated by MNA and independent variables, multiple logistic regression was used.The significance level adopted for all tests was 5% and the magnitude was tested by the odds ratio (OR) values and the confidence interval of 95% (CI 95%).The software used for statistical analysis was Stata ® version 10.0.

RESULTS
The study included 70 elderly individuals, predominantly male (57%) and aged from 60 to 69 (50%).This data and other results characterizing the sample are shown in table 1.
Almost half of the group (43%) was classified as "at risk of malnutrition", with 77% of the elderly individuals in the study group comprising "malnourished" (34%) and "risk of malnutrition", as shown in table 1.A statistically significant difference was observed  There was positive association between nutritional risk and functional class, 87% functional class III and IV patients, were malnourished or at risk of malnutrition (p=0.025).On some questions referring to weight loss and self-assessment of health status and nutritional status, a significant association was found between nutritional risk and weight loss over the last three months (p=0.003) and patient opinion on own health (p<0.001).Of those elderly individuals who reported no weight loss over the past three months, 50% were classified as "no nutritional risk," while 64%, 96% and 100% of patients that reported a loss of 1 to 3 kg, more than 3 kg or not known, were classified as "at risk of malnutrition" or "malnourished", respectively (table 2).
Regarding self-assessment of health, 100% of subjects who considered their health worse than others of the same age were classified as "at risk of malnutrition" and "malnutrition", while 13% of those who considered themselves in good health, were classified as "without nutritional risk."However, no association was found between selfassessed nutritional status and nutritional risk classification on the MNA, as shown in table 2.
The multiple logistic regression demonstrated that patients classified as functional class of CHF III and IV, reporting at least 1 kg weight loss and being female presented higher risk of be classified as "malnourished" or "risk of malnutrition" (OR 5.50, CI

DISCUSSION
Several studies have evaluated the nutritional risk of elderly individuals, 5,7,[17][18][19][20][21] but only one study (using the MNA) assessed the risk of malnutrition in elderly patients with congestive heart failure. 22he study observed "risk of malnutrition" in 71% of men and 70% of women, while 5% of men and 15% of women were classified as "malnourished", showing higher prevalence of risk of malnutrition compared to the rate observed in the present study (45% of men and 40% of women), and higher prevalence of "malnourished" compared to the rate observed in the present study (25% of men and 47% of women).Similar data in the present study is that being female presented higher risk of be classified as "malnourished" or "risk of malnutrition". 22number of studies have been carried out in elderly patients with congestive heart failure 9,[23][24][25][26] but with different objectives from those of the present study, difficulty comparisons with the findings of this research on associations between nutritional risk, weight loss and self-assessment of health status.Vedantam et al. 27 applied the MNA in an elderly population in India, observing positive association between increasing age and risk of malnutrition.Another study involving a representative sample of 1.519 Brazilian elderly individuals showed that increasing age decreased the chance of obesity and overweight with an increased chance of low weight. 28In the present study, age was significantly associated with nutritional risk, with 87% of those aged 80 years and older classified as "risk of malnutrition" or "malnourished." In a study carried out within a geriatric hospital in a sample of 83 patients, 69% of subjects were found to be at nutritional risk according to the MNA. 29Lower prevalence of malnutrition was observed in a population of hypertensive elderly (12.8%), evaluated by the body mass index. 30igh prevalence of nutritional risk was expected in our population, given the characteristics of congestive heart failure, favoring the appearance of various degrees of malnutrition.Oliveira et al., 31 in a study of a population of 240 elderly with a frequency of 37.1% of nutritional risk and 29.1% of malnutrition, found positive association between the worst MNA scores and weight loss in the last three months, as observed in this study.
In a study on the association between various factors and functional disability in elderly individuals revealing greater association with clinical conditions and increased risk of morbidity and subsequent mortality, a gradual worsening of self-assessment of health status was seen with increasing disability. 32In the present study, a significant association was observed between patient opinion on own health, functional class of CHF and MNA classification.Worsening of the limitations in CHF is usually accompanied by anorexia, fatigue and dyspnea, affecting the nutritional status. 13A is a practical tool that offers rapid implementation.However, the use of measures of arm circumference and perimeter of the leg, which may be altered due to edema common in this disease, represents a limitation in the application of the MNA in elderly patients with congestive heart failure, potentially underestimating nutritional risk.
The major limitations of this study was that the MNA was not applied early during the first two hours of hospitalization.Early application of the MNA in the first hours of hospitalization may facilitate recall by elderly individuals of their routine at home whereas a larger sample could also provide more meaningful results.

CONCLUSIONS
Most elderly individuals studied were at risk of malnutrition.Association was observed between malnourished or risk of malnutrition and age, gender, functional class of heart failure, body weight loss in the last three months, and self-assessment of health status.Age, gender, functional class, recent weight loss and selfassessment of health status should be observed during routine clinical practice, since these factors are associated with nutritional risk in elderly patients with congestive heart failure.

Table 1 .
Distribution of study population by gender, age group, nutritional risk classification and functional class.São Paulo-SP, 2010.

Table 2 .
Distribution of study population by nutritional risk classification and gender, age group, functional class of heart failure, weight loss in the last three months, and self-assessment of nutritional and of health status.São Paulo-SP, 2010. *p<0.05.