To explore the correlation between comorbidity index and sarcopenia in elderly patients.

Sixty-five elderly patients over 80 years old were included in this study. Chest CT was used to measure the cross-sectional area (cm²) and muscle density (HU) of the muscle tissue at the pedicle level of the 12 thoracic vertebral (T₁₂). The thoracic skeletal muscle index (TSMI) was calculated by dividing the cross sectional area of the T₁₂ pedicle level with the height of the patient. The difference of the Charlson comorbidity index (CCI), BMI and the laboratory indexes of patients with sarcopenia and non sarcopenia were analyzed by t test. The difference of muscle density and area between different age groups, CCI groups and bed rest groups were analyzed also by t test. The relationship between TSMI and CCI, BMI, age were analyzed using multivariate regression analysis.

All 65 elderly patients were over 80 years old, the muscle density of the 80-90 year old group was higher than that of the 90-100 year old group, the difference was statistically significant (t=2.294, P<0.05), but the difference of muscle area was not statistically significant. The muscle density and muscle area of the patients in the male and female had not significance difference (t=4.815, P<0.05), and the CCI score 6-9 groups. Muscle density and muscle area were larger than those of the 10-14 groups, and the difference was statistically significant (t=3.108, P<0.05; t=3.468, P<0.05). There was a statistically significant difference in CCI score between sarcopenia group and non sarcopenia group (t=7.754, P<0.05). There was no significant difference in BMI, serum albumin, serum creatinine, hemoglobin and myoglobin between the two groups. The linear correlation between TSMI and CCI was statistically significant (r=-0.534, P<0.05).

The comorbidity index is closely related to the occurrence of sarcopenia in elderly patients.