Background
Methods
Study population and design
Anthropometric and biochemical measurements
Statistical analysis
Results
Baseline characteristics of study participants according to sex-specific skeletal muscle mass index tertile
Lowest tertile (n = 4943) | Middle tertile (n = 4944) | Highest tertile (n = 4943) | P value | |
---|---|---|---|---|
Skeletal muscle mass index (SMI) (%) | 28.6 (2.6) | 31.0 (2.3) | 33.6 (2.5) | |
Men | 30.7 (1.1) | 32.9 (0.5) | 35.4 (1.4) | |
Women | 25.9 (1.2) | 28.4 (0.6) | 31.1 (1.4) | |
Age (year) | 52.7 (8.5) | 50.5 (7.5) | 49.0 (7.6) | < 0.001 |
Sex (women) | 2118 (42.8) | 2118 (42.8) | 2118 (42.8) | 1.000 |
Waist circumference (cm) | 85.5 (8.3) | 81.5 (7.8) | 77.3 (7.6) | < 0.001 |
Body weight (kg) | 67.0 (10.8) | 64.6 (10.2) | 61.7 (9.8) | < 0.001 |
BMI (kg/m2) | 25.1 (2.5) | 23.4 (2.1) | 21.8 (2.1) | < 0.001 |
Obesity, n (%) | 2459 (49.8) | 1125 (22.8) | 321 (6.5) | < 0.001 |
ASM (kg) | 19.3 (4.3) | 20.2 (4.3) | 20.8 (4.3) | < 0.001 |
ASM/BMI (m2) | 0.768 (0.133) | 0.856 (0.132) | 0.952 (0.145) | < 0.001 |
Fat mass (kg) | 20.0 (4.0) | 16.1 (2.7) | 12.4 (3.0) | < 0.001 |
Percent fat mass (%) | 30.1 (5.2) | 25.2 (4.2) | 20.2 (4.3) | < 0.001 |
Hypertension, n (%) | 755 (15.3) | 477 (9.6) | 348 (7.0) | < 0.001 |
SBP (mmHg) | 117.5 (15.2) | 114.3 (14.9) | 111.6 (14.6) | < 0.001 |
DBP (mmHg) | 72.4 (10.4) | 70.9 (10.6) | 69.3 (10.5) | < 0.001 |
Smoking, never/past/current, n (%) | 2801/1367/775 (56.7/27.7/15.7) | 2726/1382/836 (55.1/28.0/16.9) | 2751/1329/863 (55.7/26.9/17.5) | 0.132 |
Regular exercise, n (%) | 829 (16.8) | 692 (14.0) | 716 (14.5) | < 0.001 |
Family history of diabetes, n (%) | 476 (9.6) | 544 (11.0) | 5.31 (10.7) | 0.060 |
IFG, n (%) | 627 (12.7) | 589 (11.9) | 485 (9.8) | < 0.001 |
HbA1c (%) | 5.4 (0.4) | 5.3 (0.4) | 5.3 (0.4) | < 0.001 |
Fasting glucose (mg/dL) | 90.3 (8.8) | 89.6 (8.9) | 88.4 (9.0) | < 0.001 |
Fasting insulin (μIU/mL)a | 9.65 (3.98) | 8.52 (3.22) | 7.74 (3.12) | < 0.001 |
HOMA-IRa | 2.17 (0.93) | 1.90 (0.76) | 1.71 (0.73) | < 0.001 |
eGFR (mL/min/1.73 m2) | 89.3 (12.9) | 88.7 (12.2) | 88.5 (12.0) | 0.005 |
Total cholesterol (mg/dL) | 200.9 (33.5) | 195.8 (31.9) | 189.9 (31.6) | < 0.001 |
Triglycerides (mg/dL) | 125.4 (66.6) | 117.4 (67.4) | 101.7 (61.3) | < 0.001 |
HDL cholesterol (mg/dL) | 56.4 (13.0) | 57.2 (13.5) | 60.5 (14.6) | < 0.001 |
LDL cholesterol (mg/dL) | 129.4 (29.3) | 124.8 (27.8) | 117.5 (27.8) | < 0.001 |
C-reactive protein (mg/L) | 0.14 (0.42) | 0.11 (0.29) | 0.09 (0.27) | < 0.001 |
Relationship between baseline skeletal muscle mass index and incident metabolic syndrome
Lowest tertile (n = 4943) | Middle tertile (n = 4944) | Highest tertile (n = 4943) | P for trend | |||||
---|---|---|---|---|---|---|---|---|
Referent | HR | 95% CI | P value | HR | 95% CI | P value | ||
Model 1 | 1 | 0.56 | 0.52, 0.61 | < 0.001 | 0.26 | 0.24, 0.29 | < 0.001 | < 0.001 |
Model 2 | 1 | 0.58 | 0.54, 0.63 | < 0.001 | 0.28 | 0.25, 0.31 | < 0.001 | < 0.001 |
Model 3 | 1 | 0.91 | 0.83, 0.99 | 0.026 | 0.63 | 0.56, 0.70 | < 0.001 | < 0.001 |
Model 4 | 1 | 0.88 | 0.81, 0.97 | 0.006 | 0.60 | 0.54, 0.68 | < 0.001 | < 0.001 |
Subgroup analysesa | ||||||||
Sex | P for interaction = 0.923 | |||||||
Men (n = 8476) | 1 | 0.91 | 0.82, 1.01 | 0.088 | 0.65 | 0.57, 0.75 | < 0.001 | < 0.001 |
Women (n = 6354) | 1 | 0.87 | 0.73, 1.03 | 0.099 | 0.56 | 0.44, 0.70 | < 0.001 | < 0.001 |
Family history of diabetes | P for interaction = 0.954 | |||||||
Absence (n = 13,279) | 1 | 0.91 | 0.83, 0.99 | 0.037 | 0.62 | 0.55, 0.70 | < 0.001 | < 0.001 |
Presence (n = 1551) | 1 | 0.81 | 0.61, 1.08 | 0.144 | 0.47 | 0.31, 0.70 | < 0.001 | 0.001 |
Smoking status | P for interaction = 0.314 | |||||||
Never (n = 8278) | 1 | 0.86 | 0.75, 0.98 | 0.022 | 0.54 | 0.44, 0.65 | < 0.001 | < 0.001 |
Past (n = 4078) | 1 | 0.85 | 0.73, 0.99 | 0.039 | 0.63 | 0.52, 0.78 | < 0.001 | < 0.001 |
Present (n = 2474) | 1 | 0.95 | 0.80, 1.14 | 0.603 | 0.73 | 0.57, 0.92 | 0.009 | 0.023 |
Exercise | P for interaction = 0.325 | |||||||
Never (n = 12,593) | 1 | 0.87 | 0.79, 0.96 | 0.005 | 0.62 | 0.54, 0.70 | < 0.001 | < 0.001 |
Regular (n = 2237) | 1 | 0.99 | 0.79, 1.24 | 0.940 | 0.50 | 0.35, 0.70 | < 0.001 | < 0.001 |
Obesity | P for interaction < 0.001 | |||||||
Absence (n = 10,925) | 1 | 0.77 | 0.68, 0.87 | < 0.001 | 0.56 | 0.47, 0.66 | < 0.001 | < 0.001 |
Presence (n = 3905) | 1 | 1.04 | 0.91, 1.18 | 0.568 | 0.97 | 0.85, 1.12 | 0.698 | 0.603 |
P for interaction = 0.062 | ||||||||
Age ≤ 50 (n = 8017) | 1 | 0.92 | 0.81, 1.05 | 0.232 | 0.60 | 0.50, 0.72 | < 0.001 | < 0.001 |
Age > 50 (n = 6813) | 1 | 0.83 | 0.74, 0.94 | 0.002 | 0.63 | 0.54, 0.73 | < 0.001 | < 0.001 |
IFG | P for interaction = 0.007 | |||||||
Absence (n = 13,129) | 1 | 0.87 | 0.79, 0.96 | 0.006 | 0.59 | 0.51, 0.67 | < 0.001 | < 0.001 |
Presence (n = 1701) | 1 | 0.91 | 0.74, 1.13 | 0.399 | 0.58 | 0.44, 0.77 | < 0.001 | < 0.001 |
P for interaction = 0.019 | ||||||||
HOMA-IRb ≤ 2.5 (n = 7957) | 1 | 0.94 | 0.82, 1.07 | 0.344 | 0.71 | 0.59, 0.84 | < 0.001 | < 0.001 |
HOMA-IR > 2.5 (n = 2006) | 1 | 1.14 | 0.95, 1.37 | 0.158 | 0.80 | 0.64, 1.00 | 0.053 | 0.002 |
Clinical and laboratory characteristics at baseline and at 1-year follow-up according to changes in skeletal muscle mass index over 1 year
Group 1 (< 0%) (n =6525) | Group 2 (0–1%) (n = 3734) | Group 3 (> 1%) (n = 1380) | |||||||
---|---|---|---|---|---|---|---|---|---|
SMI 1-year increases (%) | − 0.80 (0.66) | 0.43 (0.28) | 1.65 (0.80) |
Baseline | 1-year follow up | Baseline | 1-year follow up | Baseline | 1-year follow up | P value* | P value† | P value‡ | |
---|---|---|---|---|---|---|---|---|---|
Age (year) | 51.1 (7.9) | 52.2 (7.9) | 50.5 (7.8) | 51.6 (7.8) | 49.7 (8.0) | 50.8 (8.0) | < 0.001 | < 0.001 | 0.001 |
Sex (women) | 2444 (37.5) | – | 1724 (46.2) | – | 725 (52.5) | – | < 0.001 | – | – |
Waist circumference (cm) | 81.4 (8.2) | 82.2 (8.2) | 80.9 (8.6) | 80.9 (8.3) | 80.2 (8.6) | 79.0 (8.1) | < 0.001 | < 0.001 | < 0.001 |
Body weight (kg) | 64.5 (10.1) | 65.2 (10.1) | 63.8 (10.5) | 63.4 (10.4) | 63.1 (10.5) | 61.4 (10.0) | < 0.001 | < 0.001 | < 0.001 |
BMI (kg/m2) | 23.3 (2.5) | 23.6 (2.5) | 23.3 (2.6) | 23.1 (2.6) | 23.2 (2.7) | 22.5 (2.5) | 0.750 | < 0.001 | < 0.001 |
Obesity, n (%) | 1527 (23.4) | 1817 (27.9) | 898 (24.1) | 800 (21.4) | 347 (25.1) | 220 (15.9) | 0.355 | < 0.001 | < 0.001 |
ASM (kg) | 20.5 (4.2) | 20.2 (4.2) | 19.7 (4.3) | 19.9 (4.3) | 19.2 (4.3) | 19.7 (4.3) | < 0.001 | < 0.001 | < 0.001 |
Fat mass (kg) | 15.4 (4.4) | 16.7 (4.4) | 16.4 (4.5) | 15.8 (4.3) | 16.7 (4.5) | 14.3 (4.1) | < 0.001 | < 0.001 | < 0.001 |
Percent fat mass (%) | 24.0 (6.0) | 25.7 (5.9) | 25.7 (6.0) | 25.0 (5.9) | 26.6 (6.1) | 23.4 (5.9) | < 0.001 | < 0.001 | < 0.001 |
SMI (%) | 31.7 (3.1) | 30.9 (3.1) | 30.7 (3.1) | 31.2 (3.1) | 30.3 (3.2) | 31.9 (3.2) | < 0.001 | < 0.001 | < 0.001 |
ASM/BMI (m2) | 0.881 (0.155) | 0.857 (0.151) | 0.846 (0.153) | 0.859 (0.154) | 0.826 (0.156) | 0.875 (0.160) | < 0.001 | < 0.001 | < 0.001 |
Hypertension, n (%) | 627 (9.6) | 715 (11.0) | 333 (8.9) | 356 (9.5) | 119 (8.6) | 130 (9.4) | 0.345 | 0.037 | 0.035 |
SBP (mmHg) | 113.7 (14.9) | 117.8 (15.3) | 114.4 (15.1) | 116.0 (15.5) | 114.7 (15.5) | 114.4 (15.9) | 0.017 | < 0.001 | < 0.001 |
DBP (mmHg) | 70.3 (10.3) | 74.6 (10.8) | 71.0 (10.7) | 73.0 (11.1) | 71.0 (11.1) | 71.6 (11.4) | 0.001 | < 0.001 | < 0.001 |
Smoking, never/past/current, n (%) | 3402/1944/1179 (52.1/29.8/18.1) | – | 2209/994/531 (59.2/26.6/14.2) | – | 869/319/192 (63.0/23.1/13.9) | – | < 0.001 | – | – |
Regular exercise, n (%) | 829 (12.7) | – | 573 (15.4) | – | 236 (17.1) | – | < 0.001 | – | – |
Family history of diabetes, n (%) | 590 (9.0) | – | 417 (11.2) | – | 156 (11.3) | – | 0.001 | – | – |
IFG, n (%) | 681 (10.4) | 872 (13.4) | 418 (11.2) | 451 (12.1) | 172 (12.5) | 150 (10.9) | 0.073 | 0.018 | < 0.001 |
Diabetes, n (%) | – | 91 (1.4) | – | 32 (0.9) | – | 7 (0.5) | – | 0.003 | – |
HbA1c (%) | 5.3 (0.4) | 5.4 (0.4) | 5.3 (0.4) | 5.4 (0.4)| | 5.3 (0.5) | 5.4 (0.4) | 0.098 | 0.070 | < 0.001 |
Fasting glucose (mg/dL) | 89.0 (8.7) | 91.2 (9.6) | 89.2 (8.7) | 90.3 (9.1) | 89.4 (9.4) | 89.5 (8.9) | 0.168 | < 0.001 | < 0.001 |
Fasting insulina (μIU/mL) | 8.51 (3.38) | 8.29 (3.56) | 8.62 (3.41) | 7.83 (3.54) | 8.47 (3.60) | 7.29 (3.58) | 0.379 | < 0.001 | < 0.001 |
HOMA-IRa | 1.89 (0.80) | 1.89 (0.89) | 1.92 (0.80) | 1.76 (0.86) | 1.90 (0.86) | 1.63 (0.88) | 0.249 | < 0.001 | < 0.001 |
eGFR (mL/min/1.73m2) | 88.5 (12.1) | 88.1 (12.6) | 88.8 (12.3) | 88.4 (13.1) | 89.5 (13.4) | 88.7 (14.2) | 0.042 | 0.299 | 0.496 |
Total cholesterol (mg/dL) | 195.0 (31.9) | 199.1 (32.8) | 196.9 (33.2) | 197.1 (32.2) | 196.0 (33.7) | 193.9 (32.5) | 0.018 | < 0.001 | < 0.001 |
Triglycerides (mg/dL) | 110.8 (60.2) | 115.0 (58.8) | 114.1 (69.9) | 107.9 (56.1) | 109.9 (55.6) | 97.8 (45.3) | 0.028 | < 0.001 | < 0.001 |
HDL cholesterol (mg/dL) | 58.3 (13.6) | 56.4 (13.5) | 58.8 (14.0) | 57.5 (13.8) | 59.4 (14.3) | 59.3 (13.9) | 0.016 | < 0.001 | < 0.001 |
LDL cholesterol (mg/dL) | 123.2 (28.0) | 124.2 (27.8) | 124.6 (29.1) | 121.2 (28.2) | 123.9 (29.4) | 116.5 (28.0) | 0.043 | < 0.001 | < 0.001 |
C-reactive protein (mg/L) | 0.11 (0.36) | 0.11 (0.32) | 0.11 (0.27) | 0.10 (0.24) | 0.10 (0.19) | 0.09 (0.24) | 0.144 | 0.069 | 0.125 |
Relationship between increase in skeletal muscle mass index over 1 year and incident metabolic syndrome
Group 1 (< 0%) (n = 6525) | Group 2 (0–1%) (n = 3734) | Group 3 (> 1%) (n = 1380) | P for trend | |||||
---|---|---|---|---|---|---|---|---|
Referent | HR | 95% CI | P value | HR | 95% CI | P value | ||
Model 1 | 1 | 0.91 | 0.82, 1.01 | 0.080 | 0.72 | 0.61, 0.86 | < 0.001 | < 0.001 |
Model 2 | 1 | 0.94 | 0.85, 1.05 | 0.282 | 0.77 | 0.65, 0.92 | 0.004 | 0.013 |
Model 3 | 1 | 0.90 | 0.81, 1.01 | 0.066 | 0.71 | 0.59, 0.84 | < 0.001 | < 0.001 |
Model 4 | 1 | 0.91 | 0.82, 1.01 | 0.073 | 0.71 | 0.59, 0.84 | < 0.001 | < 0.001 |
Model 5 | 1 | 0.87 | 0.78, 0.97 | 0.010 | 0.67 | 0.56, 0.79 | < 0.001 | < 0.001 |
Subgroup analysesa | ||||||||
Sex | P for interaction = 0.506 | |||||||
Men (n = 6746) | 1 | 0.83 | 0.73, 0.94 | 0.005 | 0.63 | 0.50, 0.79 | < 0.001 | < 0.001 |
Women (n = 4893) | 1 | 0.95 | 0.79, 1.16 | 0.631 | 0.78 | 0.58, 1.04 | 0.085 | 0.226 |
Baseline sex-specific SMI | P for interaction = 0.588 | |||||||
Lowest tertile (n = 3879) | 1 | 0.81 | 0.70, 0.93 | 0.004 | 0.67 | 0.53, 0.83 | < 0.001 | < 0.001 |
Middle tertile (n = 3880) | 1 | 0.98 | 0.81, 1.18 | 0.825 | 0.64 | 0.45, 0.90 | 0.011 | 0.039 |
Highest tertile (n = 3880) | 1 | 0.88 | 0.66, 1.18 | 0.397 | 0.67 | 0.40, 1.15 | 0.145 | 0.282 |
Smoking status | P for interaction = 0.204 | |||||||
Never (n = 6480) | 1 | 0.89 | 0.76, 1.04 | 0.132 | 0.74 | 0.58, 0.94 | 0.014 | 0.032 |
Past (n = 3257) | 1 | 0.76 | 0.63, 0.93 | 0.007 | 0.71 | 0.51, 0.99 | 0.045 | 0.008 |
Present (n = 1902) | 1 | 0.99 | 0.79, 1.24 | 0.941 | 0.48 | 0.31, 0.73 | 0.001 | 0.003 |
Obesity | P for interaction = 0.092 | |||||||
Absence (n = 8867) | 1 | 0.89 | 0.76, 1.03 | 0.109 | 0.77 | 0.61, 0.98 | 0.031 | 0.050 |
Presence (n = 2772) | 1 | 0.85 | 0.73, 1.00 | 0.047 | 0.56 | 0.43, 0.74 | < 0.001 | < 0.001 |
P for interaction = 0.351 | ||||||||
Age ≤ 50 (n = 6326) | 1 | 0.94 | 0.81, 1.10 | 0.462 | 0.70 | 0.55, 0.90 | 0.005 | 0.019 |
Age > 50 (n = 5313) | 1 | 0.80 | 0.69, 0.93 | 0.003 | 0.62 | 0.48, 0.81 | < 0.001 | < 0.001 |
IFG | P for interaction = 0.456 | |||||||
Absence (n = 10,368) | 1 | 0.87 | 0.77, 0.98 | 0.020 | 0.63 | 0.51, 0.77 | < 0.001 | < 0.001 |
Presence (n = 1271) | 1 | 0.79 | 0.60, 1.05 | 0.106 | 0.75 | 0.50, 1.12 | 0.154 | 0.160 |
P for interaction = 0.631 | ||||||||
HOMA-IRb ≤ 2.5 (n = 6254) | 1 | 0.83 | 0.71, 0.97 | 0.023 | 0.63 | 0.49, 0.83 | 0.001 | 0.001 |
HOMA-IR > 2.5 (n = 1447) | 1 | 0.87 | 0.69, 1.10 | 0.242 | 0.77 | 0.54, 1.09 | 0.136 | 0.233 |