Grip strength as a predictor of disease severity in hospitalized COVID-19 patients

Grip strength is one of the main components for the physical functioning in sarcopenia and physical frailty.

To explore the role of grip strength measurement at admission for predicting disease severity in COVID-19.

Demographic data, smoking status, comorbidities, COVID-19 related symptoms, grip strength, laboratory and computed tomography (CT) findings at admission were all noted. Using a Smedley hand dynamometer, the maximum grip strength value (kg) after three measurements on the dominant side was recorded. Low grip strength was defined as two standard deviations below the gender-specific peak mean value of the healthy young adults (<32 kg for males, <19 kg for females). Patients were categorized into three groups according to clinical and CT findings. Severe illness group had pneumonia with a respiratory rate >30/min, oxygen saturation ≤90%, or extensive lung involvement in CT. Moderate illness group had pneumonia with CT score ≤11. Mild illness group had normal CT findings.

The study population included 312 patients (140 F, 172 M). The distribution of mild, moderate and severe disease groups were 36.9%, 51.0% and 12.2%, respectively. Cough, fever, dyspnea, hypertension, obesity, cardiovascular disease (CVD) and chronic obstructive pulmonary disease (COPD) were most frequent, and C-reactive protein (CRP), ferritin, D-dimer, and neutrophil levels were highest in the severe group (all p<.05). Absolute grip strength values were lowest and the frequency of having low grip strength were highest in the severe group (both p<.01). Since we found that the significant differences were stemming from the severe group, we combined the mild and moderate group as non-severe, and compared severe vs. non-severe groups with binary logistic regression analyses. When age, gender, body mass index, smoking status, presence of comorbidities and low grip strength, and abnormal laboratory findings were taken into analyses; age (odds ratio [OR]: 1.054 [95% confidence interval (CI): 1.020-1.089]), obesity (OR: 2.822 [95% CI: 1.143-6.966]), COPD (OR: 5.699 [95 %CI: 1.231-26.383]), CRP level (OR: 1.023 [95% CI: 1.010-1.036]) and low grip strength (OR: 3.047 [95% CI: 1.146-8.103]) were observed to be independent predictors for severe COVID-19 disease (all p<.05).

In addition to the well-known independent risk factors (i.e. age, obesity, COPD, and CRP level), low grip strength independently increased (about three times) the severity of COVID-19.