Table 1.
Clinical characteristics of the study participants
| Characteristic | Long-COVID Syndrome (n = 99) | Control (n = 97) | P Value |
|---|---|---|---|
| Sex, n, women/men | 70/29 | 51/46 | 0.009 |
| Age, yr | 47.38 (9.99) | 52.22 (11.94) | 0.002 |
| Height, m | 1.66 (0.09) | 1.66 (0.10) | 0.853 |
| Body mass, kg | 74.53 (18.23) | 71.27 (16.04) | 0.259 |
| Body mass index, kg/m2 | 27.13 (5.88) | 26.04 (3.68) | 0.117 |
| Nutritional status by BMI, n (%) | |||
| Normal weight | 38 (38.4) | 39 (40.2) | 0.078 |
| Overweight | 33 (33.3) | 47 (48.5) | |
| Obesity | 28 (28.3) | 11 (11.3) | |
| Body fat, % | 38.93 (7.92) | 33.02 (9.31) | <0.001 |
| Visceral adiposity tissue, cm2 | 190.95 (102.66) | 137.70 (71.15) | <0.001 |
| Muscle tissue lean, % | 58.90 (7.34) | 64.55 (8.70) | <0.001 |
| Appendicular lean mass index, kg/m2 | 7.08 (1.44) | 7.63 (1.47) | 0.009 |
| Low muscle mass, n (%)a | |||
| <6.0 kg/m2 for women <7.0 kg/m2 for men | 12 (12.1) | 3 (3.1) | 0.0345 |
| Overall physical activity (MET-min/wk)b,c | 978.30 (1153.15) | 1763.40 (1694.69) | <0.001 |
| Physical activity levels, n (%)b,c | |||
| Light-intensity activity | 53 (55.2) | 35 (36.1) | <0.001 |
| Moderate-intensity activity | 40 (41.7) | 39 (40.2) | |
| Vigorous-intensity activity | 3 (3.1) | 23 (23.7) | |
| Grip strength, kg | 27.30 (10.50) | 32.70 (10.0) | <0.001 |
| Low muscle strength, n (%)d | |||
| <18 kg for women <28 kg for men | 17 (17.5) | 2 (2.0) | <0.001 |
| Leg extension 1RM, kg | 72.73 (34.34) | 93.45 (33.87) | <0.001 |
Data are means (SD). Two-tailed Student’s t tests for two samples of equal variance were performed between control and long-COVID-19 syndrome groups. The χ2 test was performed for sex-variable groups. aThe recent European Working Group on Sarcopenia in Older People (EWGSOP) guidelines suggest an appendicular lean mass index < 6.0 kg/m2 in women and appendicular lean mass index < 7.0 kg/m2 in men as diagnostic cut-off values to define low muscle mass. bData from 96 participants. cThe short, self-administered international physical activity questionnaire (IPAQ) was used to assess overall physical activity. The short form records four types of physical activity: vigorous activity such as aerobics; moderate-intensity activity such as leisure cycling; walking, and sitting, in the last 7 days. Responses were converted to metabolic equivalent task minutes per week (MET-min/wk) according to the IPAQ scoring protocol: total minutes over last 7 days spent on vigorous activity, moderate-intensity activity, and walking (light-intensity activity) were multiplied by 8.0, 4.0, and 3.3, respectively, to create MET scores for each activity level. MET scores across the three subcomponents were summed to indicate overall physical activity. dLow muscle strength was defined as grip strength <18 kg in women and <28 kg in men, according to EWGSOP guidelines.