Ultrasound Assessment of the Gastrocnemius Muscle as a Potential Tool for Identifying Sarcopenia in Patients with Type 2 Diabetes

Figures & data

Figure 1 Flowchart of participants through the study.

Table 1 Baseline Characteristics of Patients with and without Sarcopenia

	Non-Sarcopenia (n = 116)	Sarcopenia (n = 37)	p-value
Demographic characteristics
Age (years), mean±SD	55.4 ± 11.1	65.1 ± 9.5	<0.001
Male, n (%)	69 (59.5)	22 (59.5)	1.000
Height (cm), mean±SD	163.3 ± 8.1	160.4 ± 8.3	0.056
Weight (kg), mean±SD	67.7 ± 13.1	59.7 ± 8.6	0.001
BMI (kg/m^2), mean±SD	25.3 ± 3.6	23.2 ± 3.0	0.002
Medical history and Clinical condition
Hypertension, n (%)	50 (43.1)	18 (48.6)	0.688
Duration of diabetes (years), median (IQR)	6.0 (1.8, 11.0)	10.0 (4.0, 16.0)	0.079
DR, n (%)	28 (24.8)	13 (38.2)	0.188
DN, n (%)	14 (12.1)	5 (13.5)	1.000
DPN, n (%)	58 (50.0)	18 (48.6)	1.000
Laboratory examination
FBG (mmol/L), mean±SD	9.08 ± 4.00	8.81 ± 3.46	0.711
2hPBG (mmol/L), mean±SD	10.99 ±3.54	12.91 ± 4.56	0.009
HbA1C (%), mean±SD	9.60 ± 2.33	9.87 ± 1.99	0.538
Creatinine (mg/dl), mean±SD	0.81 ± 0.24	0.88 ± 0.36	0.157
Cystatin C (mg/L), mean±SD	0.96 ± 0.33	1.11 ± 0.43	0.031
eGFR (mL/min/1.73m^2), mean±SD	94.35 ±19.96	84.38 ± 22.40	0.011
Albumin (g/L), mean±SD	40.81 ± 3.67	38.81 ± 4.42	0.007
Muscle size, strength and physical performance
ASMI (kg/m^2), mean±SD	7.04 ± 2.18	5.32 ± 0.76	<0.001
Handgrip strength (kg), mean±SD	30.88 ± 9.84	20.98 ± 6.75	<0.001
6-meter walking time (s), mean±SD	5.74 ± 1.19	6.92 ± 1.83	0.001
MT (cm), mean±SD	2.23 ± 0.55	1.99 ± 0.45	0.019
CSA (cm^2), mean±SD	14.20 ± 3.52	11.41 ± 3.04	<0.001
FL (cm), mean±SD	4.08 ± 0.70	3.66 ± 0.57	0.001
PA (°), mean±SD	24.31 ± 4.08	24.18 ± 4.77	0.872
SWEstraight (kPa), median (IQR)	11.75 (9.43, 12.70)	8.80 (5.50, 10.00)	<0.001
SWEbent (kPa), median (IQR)	19.25 (14.97, 22.68)	13.25 (10.07, 21.00)	0.012

Abbreviations: BMI, body mass index; DR, diabetic retinopathy; DN, diabetic nephropathy; DPN, diabetic peripheral neuropathy; FBG, fasting blood glucose; 2hPBG, 2 hours postprandial blood glucose; HbA1c, glycosylated hemoglobin; eGFR, estimated glomerular filtration rate; ASMI, appendicular skeletal muscle mass index; MT, muscle thickness; CSA, cross-sectional area; FL, fascicle length; PA, pennation angle; SWE, shear wave ultrasound elastography.

Table 2 Correlation Between Clinical Indicators and US Features

Indicators	MT	CSA	FL	PA	SWEstraight	SWEbent
ASMI	0.39*	0.56*	0.27*	0.22*	−0.02	−0.11
Handgrip strength	0.25*	0.45*	0.21*	0.16*	0.26*	0.07
6-meter walking time	−0.07	−0.07	−0.12	0.11	−0.10	−0.16

Note: The symbol * indicates statistically significant difference: a two-sided p value <0.05.

Abbreviations: ASMI, appendicular skeletal muscle mass index; MT, muscle thickness; CSA, cross-sectional area; FL, fascicle length; PA, pennation angle; SWE, shear wave ultrasound elastography.

Table 3 Stepwise Regression of Sarcopenia

	aOR (95% CI)	p-value
Age	1.07 (1.01–1.13)	0.045
CSA	0.83 (0.69–0.98)	0.039
SWEstraight	0.75 (0.60–0.89)	0.017

Abbreviations: CSA, cross-sectional area; SWE, shear wave ultrasound elastography; aOR, adjusted odds ratio; CI, confidence interval.

Figure 2 The results of ROC curve of the model in identifying sarcopenia. (A) The AUC, sensitivity and specificity of the model in total participants. (B) The AUC, sensitivity and specificity of the model in male. (C) The AUC, sensitivity and specificity of the model in female.

Table 4 Stepwise Regression of ASMI

	β (95% CI)	p-value
Weight	0.05 (0.03–0.07)	<0.001
Cr	0.99 (0.08–1.90)	0.034
MT	0.76 (0.35–1.18)	<0.001

Abbreviations: ASMI, appendicular skeletal muscle mass index; Cr, creatinine; MT, muscle thickness; CI, confidence interval.

Figure 3 Correlations between the estimated ASMI and actual ASMI.

Figure 4 The results of ROC curve of the model in identifying low muscle mass. (A) The AUC, sensitivity and specificity of the model in male. (B) The AUC, sensitivity and specificity of the model in female.

Abbreviations: ROC, receiver operating characteristic; AUC, area under the curve; ASMI, appendicular skeletal muscle mass index.

Data Sharing Statement

Data relevant to this study are available from the corresponding authors upon reasonable request.