(Table 5).
No statistically significant correlation was found between muscle ultrasound evaluations and adiponectin and leptin levels within the sarcopenic group. It was found that there was also a weak positive correlation between adiponectin level and rectus abdominis muscle thickness within the non-sarcopenic group. A moderate-weak and positive correlation was found between the leptin level and bilateral gastrocnemius subcutaneous tissue thickness, left gastrocnemius muscle thickness, bilateral rectus femoris subcutaneous tissue thickness and rectus abdominis subcutaneous tissue thickness. When the relationship between body composition values measured by DEXA and muscle parameters measured by the US were examined; a statistically significant, moderate and positive correlation was found between FMI and rectus abdominis muscle thickness in patients of group 1. A statistically significant, strong and positive correlation was found between SMI and bilateral gastrocnemius muscle thickness.
When stepwise multiple linear regression analysis was performed, hip circumferences and gastrocnemius muscle thickness (Model 1) were found to be significant predictors for SMI (r=0.998, r2=0.995). The significant variables (p < 0.05 according to correlation analyses) included in Model 1 are age, body mass index, waist and hip circumferences, gait speed, rectus femoris and gastrocnemius medialis muscle thicknesses. Model 2 was included age, body mass index, waist and hip circumferences, gait speed, grip strength, rectus femoris and gastrocnemius medialis muscle thicknessesIn (Model 2); hip circumferences and gastrocnemius muscle thickness were significant predictors for gait speed (r=1.000, r2=1.000). Gastrocnemius muscle thickness was the strongest predictor (with a high standardized regression coefficient) for gait speed in both models.
There was a moderate positive correlation (r: 0.643, p: 0.024) between walking speed and vitamin D levels and a moderately negative correlation (r: -0.615, p: 0.033) with fat mass (FM). A moderate negative correlation (r:-0.594, p: 0.042) was found between the timed up to go test and leptin levels.