Sarcopenia correlates with systemic inflammation in COPD

Figures & data

Table 1 Baseline characteristics of study subjects

Variable	Total (n=80)	With sarcopenia (n=20, 25%)	Without sarcopenia (n=60, 75%)	P-value
Age (years)	68.4±8.9	73.1±8	66.8±8.7	0.006
Male (%)	67 (83.8)	17 (85)	50 (83.3)	0.585
BMI (kg/m^2)	23.3±3.2	21.1±1.7	24.1±3.2	<0.001
Comorbidities (%)
Diabetes	20 (25)	6 (30)	14 (23.3)	0.374
Hypertension	38 (47.5)	12 (60)	26 (43.3)	0.181
Cardiovascular disease	19 (23.8)	10 (50)	9 (15)	0.003
Tuberculosis	26 (32.5)	6 (30)	20 (33.3)	0.507
Bronchiectasis/emphysema	19 (23.8)	3 (15)	16 (26.7)	0.228
Body composition and strength
WHR	0.92±0.04	0.90±0.16	0.91±0.05	0.464
Fat mass (kg)	15.7±5.3	13.8±3.6	16.4±5.6	0.056
FMI (kg/m^2)	5.8±1.9	5.1±1.4	6±2.1	0.087
Body fat (%)	24.6±5.9	24.1±5.1	24.7±6.5	0.729
FFM (kg)	47.4±6.9	42.8±4.6	49±7.4	<0.001
FFMI (kg/m^2)	17.4±1.6	15.9±1	17.9±1.5	<0.001
SMM (kg)	25.9±4.7	22.8±3.5	27±4.6	0.001
SMMI (kg/m^2)	9.5±1.2	8.5±0.8	9.8±1.1	<0.001
HGS (kg)	30.6±9.3	25.4±6.1	32.9±9.8	0.002
Pulmonary function*
FEV1 (%)	61.2±14.3	58±13.9	62.3±13.9	0.253
FEV1/FVC (%)	51±12.9	46.1±13	52.6±12.8	0.05
GOLD stage, 2011 revised# (%)				0.624
A	24 (30)	4 (20)	20 (33.3)
B	31 (38.8)	9 (45)	22 (36.7)
C	5 (6.2)	2 (10)	3 (5)
D	20 (25)	5 (25)	15 (25)

Notes:

* Postbronchodilator;

# According to 2011 GOLD revision. Data expressed as mean ± standard deviation or n (%).

Abbreviations: BMI, body mass index; WHR, waist:hip ratio; FMI, fat mass index; FFM, fat-free mass; FFMI, FFM index; SMM, skeletal muscle mass; SMMI, SMM index; HGS, handgrip strength; FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; GOLD, Global Initiative for Chronic Obstructive Lung Disease.

Table 2 Clinical outcomes according to presence or absence of sarcopenia

Variable	With sarcopenia (n=20, 25%)	Without sarcopenia (n=60, 75%)	P-value
mMRC score	0.95±0.86	0.62±0.71	0.044
0–1	15 (75%)	51 (85%)	0.059
2–4	5 (25%)	9 (15%)
CAT score	15 (7–22)	14 (8.75–21.25)	0.678
<10	6 (30)	26 (43.3)	0.216
≥10	14 (70)	34 (56.7)
BODE index	3 (0–6)	1 (0–4)	0.001
6MWD (m)	350.8±78	389.3±66.9	0.042
Acute exacerbations ≥1/year (n)	9 (45)	22 (36.7)	0.343
Inflammatory biomarkers
IL-6*	1.36±0.81	0.64±0.69	0.044
hsTNFα*	0.72±1.01	−0.03±1.16	0.013

Notes:

* Log-transformed value. All data expressed as mean ± SD or n (%) except for CAT score, BODE index, and number of acute exacerbation in the previous year (median with inter-quartile ranges).

Abbreviations: mMRC, modified Medical Research Council; CAT, COPD Assessment Test; 6MWD, 6-minute walk distance; hsTNFα, high-sensitivity TNFα; BODE, body (mass index), (airflow) obstruction, dyspnea, exercise (capacity); SD, standard deviation.

Table 3 Correlations among HGS, SMMI, and inflammatory biomarkers

Variable	HGS		SMMI
	Coefficient	P-value	Coefficient	P-value
Age	−0.415	<0.001	−0.074	0.527
BMI	0.001	0.998	0.852	<0.001
HGS	1	–	0.427	<0.001
FFMI	0.346	0.002	0.99	<0.001
FMI	−0.325	0.004	0.275	0.017
SMMI	0.427	<0.001	1	–
FEV1*	−0.103	0.367	0.018	0.88
FEV1/FVC*	−0.13	0.367	0.079	0.498
mMRC score	−0.346	0.002	−0.062	0.595
6MWD	0.44	<0.001	0.015	0.899
BODE index	−0.216	0.045	−0.257	0.026
CAT score	−0.236	0.048	−0.132	0.275
IL-6#	−0.273	0.018	−0.227	0.048
hsTNFα#	−0.35	0.002	−0.246	0.044

Notes:

* Postbronchodilator;

# log-transformed value.

Abbreviations: BMI, body mass index; HGS, handgrip strength; FFMI, fat-free mass index; FMI, fat mass index; SMMI, skeletal muscle mass index; FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; mMRC, modified Medical Research Council; 6MWD, 6-minute walk distance; CAT, COPD Assessment Test; hsTNFα, high-sensitivity TNFα; BODE, body (mass index), (airflow) obstruction, dyspnea, exercise (capacity).

Figure 1 Correlation of handgrip strength and skeletal muscle mass index with high-sensitivity TNFα.

Abbreviation: TNFα, Tumor necrosis factor alpha.

Table 4 Factors associated with sarcopenia

Variable	Sarcopenia
	Univariate analysis	Multivariate analysis
	OR (95% CI) P-value	OR (95% CI)	P-value
Age
Years	1.11 (1.03–1.22) 0.009	1.19 (1.03–1.36)	0.017
Sex
Male vs female	1.13 (0.28–4.6) 0.861	–	–
BMI
kg/m^2	0.63 (0.48–0.82) 0.001	0.52 (0.35–0.78)	0.001
Diabetes
Presence	1.41 (0.38–3.02) 0.552	–	–
Cardiovascular disease
Presence	5.66 (1.8–12.65) 0.003	4.66 (1.01–18.31)	0.048
GOLD stage
A–B	1	–	–
C–D	1.26 (0.43–3.67) 0.676	–	–
hsTNFα*	1.81 (1.1–2.99) 0.019	1.99 (1.04–3.81)	0.038

Notes:

* Log-transformed value. Multivariate logistic analysis was performed after adjusting for age, sex, BMI, and diabetes.

Abbreviations: OR, odds ratio; CI, confidence interval; BMI, body mass index; GOLD, Global Initiative for Chronic Obstructive Lung Disease; hsTNFα, high-sensitivity TNFα.