Nutritional Biomarkers As Predictors of Clinical Outcomes Between COVID-19 Severity Groups in a Tertiary Government Hospital

Background: Malnutrition, as defined by the World Health Organization (WHO), includes undernutrition. In the Philippines, malnutrition is common due to several factors. The nutritional biomarkers can be used as an alternative indicator of dietary intake and nutritional status that can detect deficiencies in support to clinical management of COVID-19 patients. Apart from that, biomarkers are potentially useful for screening, clinical management, and prevention of serious complications of COVID-19 patients. Serum albumin, c-reactive protein (CRP), leukocyte count, lymphocyte count, blood urea nitrogen (BUN) to compute the nutritional prognostic indices (Prognostic nutritional index (PNI) score, BUN/Albumin ratio (BAR) and CRP/Albumin ratio (CAR).

Objectives: To compare the nutritional biomarkers of patients with COVID-19 based on case severity and determine the nutritional prognostic indices and associate to patients' clinical outcome during hospital stay.

Methods: A single center, cross-sectional study was performed between June 2021 to August 2021 in a COVID-19 designated referral center in CALABARZON which comprised of 167 patients as part of the study. Clinicodemographic profile including patients' age, sex, co-morbidities, weight, height, laboratory, and serum biomarkers during the first 48 h of admission (serum albumin, leukocyte count, lymphocytes count, CRP, and BUN) were collated wherein the nutritional prognostic indices were computed and analyzed. Clinical outcomes of the patients were based on the patients' final diagnoses (recovered, length of hospital stay (LOHS), progression of severity and mortality).

Results: 167 non-critically ill COVID-19 patients were included in the analysis, of which 52.7% are admitted under the COVID-19 severe group and 47.3% for COVID-19 Mild/Moderate. Mostly are male (53.3%) with an average body mass index (BMI) of 24.26 (SD = 3.52) and have hypertension (55.1%) and diabetes (42.5%). Among the nutritional biomarker, albumin (p = 0.028; p = 0.004), total lymphocyte count (TLC) (p = 0.013; p = 0.005) and BUN (p = 0.001; p=<0.001) were shown to be significantly associated with progression of severity and mortality. Univariate logistic regression analysis showed the following nutritional prognostic score were correlated. (1.) progression of COVID-19 severity: PNI score (OR 0.928, 95% CI 0.886, 0.971, p=<0.001), and BAR value (OR 1.130, 95% CI 1.027, 1.242, p = 0.012); (2.) Mortality: PNI score (OR 0.926, 95% CI 0.878, 0.977, p = 0.005), CAR (OR 1.809, 95% CI 1.243, 2.632, p = 0.002), and BAR (OR 1.180, 95% CI 1.077, 1.292, p=<0.001). The average LOHS of COVID-19 patients was 12 days (SD = 7.72). However, it does not show any significant correlation between any nutritional biomarker, prognostic indices and LOHS.

Conclusion: This study demonstrated that deranged level of nutritional biomarkers can affect patient's COVID-19 severity and associated with patient's clinical outcome. Low albumin (≤2.5  g/dL), low level of TLC (≤1500 cells/mm3), elevated BUN (≥7.1 mmol/L) are associated with patient's case severity progression and mortality while low PNI score (<42.49), high BAR value (≥2.8) and CAR value (≥2.04) provided an important nutritional prognostic information and could predict mortality which can be a useful parameter in admission, hence it is recommended to screen all COVID-19 patients to reduce mortality.