In this study, 40 patients were studied. The mean and standard deviation of the subjects were 65.83 ± 15.6 years. 17 (42.5%) patients were female and 23 (57.5%) were male. It should be noted that this number included only patients who had been hospitalized for at least 7 days, and 40 patients, including those who had been discharged or died earlier than 7 days, were not due to patients who had died or died from the community We left the statistics and replaced the new patient. Participant characteristics are shown in table 1.
The results of quadriceps muscle atrophy
In this stage of the study, ultrasonography was performed to obtain the degree of atrophy of the quadriceps muscle of the patients, so that the patients underwent ultrasonography of the quadriceps muscle in the first day after mechanical ventilator admission, and once 48 hours later from admission and once on the seventh day, ultrasound was performed.
The average depth of quadriceps muscle 40 patients in ultrasound of the first day was 20.26 ± 6.976 in the second time of ultrasound 16.64 ± 6.248 and in the third time ultrasound was 14.33 ± 5.179, indicating a decrease in the depth and thickness of the muscle after admission. Statistical analysis of the results showed that the depth of muscle on the seventh day was significantly lower than the first day (P = 0.0008). However, the depth of muscle was not significantly different at the second time with ultrasound than the first time and in the third time, compared to the second time. The results of this step are presented in Fig 1 and Table 2.
The results of inflammatory factors evaluation
The results of the ESR test in the first day were 54.43 ± 27.06 in the second time, 41.83 ± 20.65 and in 7 days after admission, it was 37.15 ± 14.66. Statistical analysis showed a statistically significant difference between ESR on day 1 and day 7 (P = 0.0013) and day 1 compared to day 2 with P value = 0.025 (Fig 2a and Table2).
The results of the CRP test in the first day was 37.2 ± 18.026 in the second phase, was 26.14 ± 16.29 and 26.25 ± 11.26 at the 7 days after admission. Statistical analysis showed a significant difference between CRP level on day 1 and day 7 with P value = 0.0013 and CRP on day 1 and day 2 with P value = 0.022 (Fig 2b and Table2).
Also the result of the PCT test in the first day was 17.98 ± 14.19 for the second time, 7.348 ± 6.516, and at the final time, it was 6.925 ± 6.27. Statistical analysis showed a significant difference between PCT levels on day 1 and day 7 with a P value = 0.016 and PCT on day 1 and day 2 with a P value = 0.025(Fig 2c and Table2).
The results of proinflammatory cytokine evaluation
IL-1β secretion level of serum in the first day was 14.43 ± 8.04 pg/ml in the second day, 13.79 ± 6.61 pg/ml and in 7 days after admission, it was 16.1 ± 9.02 pg/ml. There was no statistically significant difference in the secretion level of IL-1b in three time (Fig 3a and Table 2).
IL-6 secretion level of serum in the first day was 3.96 ± 2.24 pg/ml in the second day, 3.65 ± 1.86 pg/ml and in 7 days after admission, it was 4.25 ± 2.44 pg/ml. There was no statistically significant difference in the secretion level of IL-6 in three time (Fig 3b and Table 2).
TNF-α concentration level of serum in the first time was 167.9 ± 65.08 pg/ml in the second time, 155.6 ± 85.12 pg/ml and in 7 days after admission, it was 194.7 ± 99.61 pg/ml. There was no statistically significant difference in the secretion level of TNF-α in three time of measurement (Fig 3c and Table 2).
Correlation between various inflammatory factors and quadriceps muscle atrophy
As manifested by the results, there was a positive correlation between the reduction of muscle depth in the quadriceps of patients and the Early rate of ESR, CRP and PCT. This correlation for ESR was statistically significant with P value <0.0001 and r = 0.698 and for CRP was statistically significant with P value =0.4nd to r = 0.53, Also, the correlation between quadriceps atrophy and PCT was statistically significant with P value <0.0001 and r = 0.786 (Fig 4).
In this study we also assessed correlation between early proinflammatory cytokine and quadriceps muscle atrophy. it was found that there was a positive correlation between the quadriceps atrophy of COPD patients and the early concentration of IL-1β, IL-6 and TNF-α. This correlation for IL-1b was statistically significant with P value =0.032 and r = 0.338 and for IL-6 was statistically significant with P value =0.0013 nd to r = 0.49, Also, the correlation between quadriceps atrophy and TNF-α was statistically significant with P value =0.005 and r = 0.43 (Fig 5).