Supplementary Table 1Baseline characteristics and bone mineral density (BMD) according to skeletal muscle index

Skeletal muscle index (n=1,281) / P value
for trend
Total (n=1,281) / Quartile 1 (n=318) / Quartile (n=324) / Quartile (n=319) / Quartile 4 (n=320)
Skeletal muscle index, kg/m2 / 8.4 / ± / 0.7 / 7.6 / ± / 0.4 / 8.2 / ± / 0.1 / 8.7 / ± / 0.1 / 9.3 / ± / 0.4 / < 0.001
Age, year / 71.0 / ± / 4.4 / 72.2 / ± / 4.8 / 71.4 / ± / 4.3 / 70.6 / ± / 4.3 * / 69.8 / ± / 3.6 *† / < 0.001
Height, cm / 152.8 / ± / 5.5 / 151.2 / ± / 5.7 / 152.6 / ± / 5.3 * / 153.5 / ± / 5.1 * / 153.9 / ± / 5.4 *† / < 0.001
Δ Height, cm / -3.3 / ± / 2.5 / -3.5 / ± / 2.4 / -3.3 / ± / 2.5 / -3.1 / ± / 2.5 / -3.3 / ± / 2.6 / 0.144
Weight, kg / 56.7 / ± / 8.0 / 50.2 / ± / 6.1 / 54.9 / ± / 6.0 * / 58.4 / ± / 6.2 *† / 63.2 / ± / 7.4 *†‡ / < 0.001
BMI, kg/m2 / 24.3 / ± / 3.0 / 22.0 / ± / 2.5 / 23.6 / ± / 2.2 * / 24.8 / ± / 2.5 *† / 26.7 / ± / 2.6 *†‡ / < 0.001
Body fat, % / 34.0 / ± / 6.0 / 33.4 / ± / 6.5 / 33.8 / ± / 5.8 / 34.2 / ± / 6.1 / 34.7 / ± / 5.5 * / 0.038
25(OH)D, ng/mL / 17.2 / ± / 7.9 / 16.9 / ± / 8.4 / 18.1 / ± / 8.2 / 17.0 / ± / 7.6 / 16.7 / ± / 7.4 / 0.108
Osteocalcin, ng/mL / 19.6 / ± / 9.0 / 20.2 / ± / 9.6 / 19.8 / ± / 10.2 / 18.9 / ± / 7.7 / 19.4 / ± / 8.3 / 0.295
BMD, g/cm2
Lumbar spine / 0.797 / ± / 0.139 / 0.745 / ± / 0.135 / 0.791 / ± / 0.137 * / 0.808 / ± / 0.130 * / 0.844 / ± / 0.133 *†‡ / < 0.001
Total hip / 0.732 / ± / 0.102 / 0.684 / ± / 0.095 / 0.719 / ± / 0.096 * / 0.743 / ± / 0.094 *† / 0.780 / ± / 0.097 *†‡ / < 0.001
Femur neck / 0.594 / ± / 0.096 / 0.554 / ± / 0.093 / 0.583 / ± / 0.087 * / 0.602 / ± / 0.091 *† / 0.636 / ± / 0.093 *†‡ / < 0.001
Previous fracture, n (%) / 291 (22.7) / 85 (26.7) / 65 (20.1) / 75 (23.5) / 66 (20.6) / 0.159
Parental hip fracture, n (%) / 61 (4.8) / 15 (4.7) / 16 (4.9) / 15 (4.7) / 15 (4.7) / 0.951
Falling over the past year, n (%) / 335 (26.2) / 106 (33.3) / 97 (29.9) / 65 (20.4) / 67 (20.9) / < 0.001
Physical activity
< 3 times per week / 871 (68.0) / 227 (71.4) / 204 (63.0) / 226 (70.8) / 214 (66.9) / 0.746
3-4 time per week / 306 (23.9) / 60 (18.9) / 89 (27.5) / 75 (23.5) / 82 (25.6)
≥ 5 times per week / 104 (8.1) / 31 (9.7) / 31 (9.6) / 18 (5.6) / 24 (7.5)
Depression, n (%) / 166 (13.0) / 42 (13.2) / 43 (13.3) / 34 (10.7) / 47 (14.7) / 0.242
Cognitive impairment, n (%) / 403 (31.5) / 104 (32.7) / 97 (2997) / 98 (30.7) / 104 (32.5) / 0.985

Data are shown as mean ± SD. Previous fracture includes all fractures occurred in vertebra, hip, or any other peripheral areas.

*vs. Quartile 1; † vs. Quartile 2; ‡ vs. Quartile 3

Δ heightheight at present minus height at 20 years of age,BMD bone mineral density,BMI body mass index

Supplementary figure legend

Supplementary Fig. 1 Prevalence of osteoporosis (A) and vertebral fracture (B) according to skeletal muscle index. Osteoporosis was defined as a T-score of ≤-2.5 at the lumbar spine, total hip, or femoral neck. Vertebral fracture was defined as an increase of ≥1 grade deformity on radiography. * vs. Q1; † vs. Q2; ‡ vs. Q3.

Supplementary Fig. 2Combined effects of jump power and skeletal muscle index on vertebral fracture. *P<0.05.

Supplementary Fig. 3 Prevalence of osteoporosis (A) and vertebral fracture (B) according to grip strength. Osteoporosis was defined as a T-score of ≤-2.5 at the lumbar spine, total hip, or femoral neck. Vertebral fracture was defined as an increase of ≥1 grade deformity on radiography.