2.1. Study Design and Sample
This study utilized a cross-sectional study design. A population of 184 elderly patients with CHF who were hospitalized in the cadre ward of the First Hospital of Jilin University was selected. The duration of hospitalization of these patients was limited to January 20, 2021 to October 20, 2021. CHF is a diagnosis of HF by echocardiography, clinical history, symptoms, and the history is more than 6 months. Participants were hospitalized patients 60 years of age or older with a diagnosis of CHF. The exclusion criteria were patients' refusal to accept the Comprehensive Geriatric Assessment Questionnaire. Patients unable to cooperate with the completion of the research contents, such as consciousness disorders, deafness, aphasia; Diabetic patients; Alzheimer's disease; dementia after cerebrovascular disease were clearly diagnosed; Patients with dementia caused by neurodegenerative diseases; Lack of basic data or laboratory indicators; Use of glucocorticoids within the past 1 year; Bedridden for a long time, unable to eat through the mouth; Current or previous malignancies, immune system disorders, severe liver and kidney dysfunction and other serious medical conditions. There were 208 inpatients were definitively diagnosed with CHF, of which 17 did not meet the inclusion criteria, 3 patients had missing laboratory indicators, and 4 others refused to participate, and 184 inpatients participated and completed the survey.
2.2. Measurements
2.2.1. Socio-Demographic and general information
Sociodemographic characteristics, including age, sex, and education, were assessed using a self-made face-to-face interview questionnaire. Physical indicators included height, weight, body mass index, waist circumference, arm circumference and calf circumference, which were routine examination items on the day of admission. Clinical information was gathered from electronic medical records, including smoking history, drinking history, hemoglobin(HB), hematocrit (HCT) and lymphocyte absolute value, aspartate transaminase, alanine transaminase, alkaline phosphatase, albumin, prealbumin, Blood urea nitrogen (BUN), creatinine, uric acid, retinol binding protein, inhibition C, Estimated Glomerular Filtration Rate (eGFR), cholesterol, triglyceride, low density lipoprotein cholesterol, high-density lipoprotein cholesterol, left atrial diameter, left ventricular end diastolic diameter.
Nutrition measures included: Body mass index (BMI), waist circumference, arm circumference, calf circumference, fat free mass, upper arm muscle dimension, serum albumin, prealbumin, lymphocyte absolute value, cholesterol, triglyceride, low density lipoprotein cholesterol, and high-density lipoprotein cholesterol.
2.2.2. Body Composition Analysis
The body composition of the patients was measured by Bioelectrical Impedience Analysis (BIA) using the Inbody S10 device (Biospace, Seoul, Korea)[16]. All patients were supine for 10 minutes before analysis. In the analysis, the patients were supine with arms abduction of 15°, starting from the torso and legs separated shoulder-width apart. Eight electrodes were placed between the hands (thumbs and middle fingers) and between the ankles and heels of the patients. Alcohol was applied to clean the skin before placing the electrodes to reduce skin contact resistance. The patient's age, gender, height and weight were input to measure the patient's fat free mass, visceral fat area and upper arm muscle dimension. The measurement process in this study was completed by the same physician in the cadre ward department of the First Hospital of Jilin University.
2.2.3. Cognitive Function
The Min-Mental State Examinatsion (MMSE) is the psychometric screening tool most frequently administered to assess cognitive function. It is a straightforward and rapid test that can be applied by any clinician to assess overall cognitive functioning, and is especially used extensively in primary assessments[17]. The MMSE consists of 30 items, surveying five areas, including direction, registration, attention and calculation, recall and language. The MMSE score ranges from 0 to 30, and the lower the score, the worse the cognitive function[18]. In this study, we classified the boundary of cognitive normality according to the level of education into primary school education > 20 points, junior high school or above > 24 points, below which was defined as cognitive dysfunction[19].
2.2.4. Malnutrition
Nutritional status was comprehensively assessed by multiple indicators, including clinical assessment, dietary history, anthropometric assessment, and laboratory examination results assessment[20]. We through the use of Mini Nutritional Assessment(MNA), anthropometric assessment indicators (such as BMI, waist circumference, arm circumference, calf circumference) and body composition analysis indicators༈such as fat free mass, upper arm muscle dimension ) and laboratory indexes༈such as serum albumin, prealbumin, lymphocyte absolute value, cholesterol, triglyceride, low density lipoprotein cholesterol, high-density lipoprotein cholesterol) to comprehensive evaluate the Nutritional status of patients. MNA is the most mature nutrition screening and assessment tool for the elderly, and also a good prognostic tool for the detection of malnutrition. MNA, developed in 1994 and patented by Nestle, is an assessment tool specifically designed for the elderly to assess malnutrition[21]. The test has four parts: anthropometric, holistic assessment, dietary questionnaire and subjective assessment. Subjects with an MNA score greater than or equal to 24 were nutritionally normal, while those with an MNA score less than or equal to 17 were classified as malnourished; Subjects with an MNA score between 17 and 24 are at risk of malnutrition[20].
2.3. Data Analysis
Statistical analysis was performed using SPSS/ Win 23.0 software (IBM, Armonk, NY, USA). Continuous variables were analyzed using means and standard deviations, and categorical variables were analyzed using percentages. The chi-square test was used to describe the prevalence of CI according to the characteristics of the patients. The prevalence of malnutrition based on patients' cognitive status was calculated by independent t-test and chi-square test. In order to determine the impact of malnutrition on CI in elderly patients with CHF, after adjusting for confounding factors, multivariate Logistic regression analysis was used to observe OR value and 95% confidence interval. By drawing ROC curve and calculating AUC value, The relationship between different nutritional indexes and cognitive impairment in patients with chronic heart failure was determined. A P value less than 0.05 was considered statistically significant.