The relationship between nutritional status and heart rate variability in elderly patients

Aim: Malnutrition is a common health problem in elderly patients. Prognostic nutritional index (PNI) and geriatric nutritional risk index (GNRI) are two easilycalculable indexes developed as indicators of nutritional status, showing prognosis relationships with some diseases. We planned a study to define the relationship between PNI, GNRI, which indicates nutritional status and is also a criterion of frailty, and heart rate variability (HRV), which is a cardiovascular risk marker. Material and Methods: A total of 96 patients over 65 years of age who had no known chronic disease other than controlled hypertension and regulated diabetes and who underwent rhythm holter monitoring were evaluated. Framingham risk scores (FRS), PNI, GNRI of the patients were calculated. HRV parameters were recorded. Results: The root mean square of successive differences (rMSSD) (p:0.02) and percentage of adjacent RR intervals with a difference of duration >50ms (pNN50) (p:0.035) were significantly lower in the patient group with low PNI. HRV frequency domain parameters, low-frequency/high-frequency (LF/HF) (p:0.048) and total power (TP) (p:0.044) were significantly higher in the patient group with low PNI. There was no significant relationship between GNRI and HRV parameters. Discussion: PNI is a simple indicator of decreased HRV and increased cardiac risk in elderly patients. PNI is more valuable than GNRI in predicting increased cardiac risk related to HRV in elderly patients. The results of our study support the effect of adequate nutrition on cardiac autonomic modulation in the elderly and confirm that nutrition in this age group is a correctable cardiac risk factor.