Table 1.
Baseline characteristics of the study population according to combination of low muscle strength and obesity groups
| Overall (n = 930) | Neither low strength nor obesity (n = 458) | Low strength (n = 239) | Obesity (n = 162) | Low strength and obesity (n = 71) | Pa | |
|---|---|---|---|---|---|---|
| Measures of mobility | ||||||
| Usual walking speed, ms−1; mean (s.d.) | 1.04 (0.29) | 1.14 (0.24)* | 0.93 (0.29)* | 1.08 (0.22)* | 0.86 (0.27) | <0.0001 |
| Mobility disabilityb, n (%) | 50 (5.4) | 9 (2.0)* | 24 (10.0) | 7 (4.3)* | 10 (14.1) | 0.021 |
| Muscle strength and obesity | ||||||
| Body mass index, kg/m2; mean (s.d.) | 27.5 (4.0) | 26.2 (2.5)* | 25.0 (2.6)* | 32.6 (2.2) | 33.0 (3.2) | <0.0001 |
| Waist circumference (male), cm; mean (s.d.) | 93.9 (6.8) | 93.9 (6.8)* | 90.5 (7.8)* | 106 (7.1) | 105 (6.7) | <0.0001 |
| Waist circumference (female), cm; mean (s.d.) | 90.7 (10.7) | 87.2 (8.2)* | 84.9 (9.3)* | 100.9 (7.7) | 101.1 (8.7) | <0.0001 |
| Knee extensor strength (male), kg; mean (s.d.) | 19.6 (6.1) | 22.4 (4.9)* | 12.9 (2.9) | 23.5 (4.1)* | 14.1 (2.3) | <0.0001 |
| Knee extensor strength (female), kg; mean (s.d.) | 13.2 (4.2) | 15.0 (3.5)* | 8.9 (1.7) | 15.7 (3.5)* | 9.3 (1.6) | <0.0001 |
| Potential confounders | ||||||
| Age, years; mean (s.d.) | 74.1 (6.8) | 72.5 (6.0)* | 77.7 (7.4) | 71.9 (5.2)* | 77.3 (6.6) | <0.0001 |
| Sex (female), n (%) | 513 (55.2) | 241 (52.6) | 126 (52.7) | 100 (61.7) | 46 (64.8) | 0.037 |
| Education, years; mean (s.d.) | 5.5 (3.3) | 5.8 (3.2)* | 5.2 (3.3) | 5.6 (3.3)* | 4.4 (3.4) | 0.31 |
| Physical activity, n (%) | <0.0001 | |||||
| Sedentary | 154 (16.6) | 49 (10.8)* | 54 (22.7)* | 26 (16.1)* | 25 (35.2) | |
| Moderately active | 410 (44.3) | 189 (41.5) | 107 (45.0) | 80 (49.4) | 34 (47.9) | |
| Highly active | 362 (39.1) | 217 (47.7) | 77 (32.4) | 56 (34.6) | 12 (16.9) | |
| Smoking, n (%) | 0.21 | |||||
| Never | 544 (58.5) | 251 (54.8) | 145 (60.7) | 104 (64.2) | 44 (62.0) | |
| Former | 256 (27.5) | 137 (29.9) | 55 (23.0) | 43 (26.5) | 21 (29.6) | |
| Current | 130 (14.0) | 70 (15.3) | 39 (16.3) | 15 (9.3) | 6 (8.5) | |
| Diseases | ||||||
| Hypertension, n (%) | 334 (35.9) | 141 (30.8)* | 97 (40.6) | 62 (38.3) | 34 (47.9) | 0.050 |
| Angina pectoris, n (%) | 43 (4.6) | 12 (2.6)* | 14 (5.9) | 10 (6.2) | 7 (9.9) | 0.020 |
| Chronic heart failure, n (%) | 42 (4.5) | 9 (2.0)* | 18 (7.5) | 8 (4.9) | 7 (9.9) | 0.013 |
| Diabetes, n (%) | 119 (12.8) | 45 (9.8)* | 31 (13.0) | 27 (16.7) | 16 (22.5) | 0.005 |
| Lung diseasec, n (%) | 84 (9.0) | 37 (7.9) | 28 (12.4) | 11 (6.7) | 8 (11.6) | 0.14 |
| Hip osteoarthritis, n (%) | 49 (5.3) | 16 (3.5)* | 16 (6.7) | 8 (4.9) | 9 (12.7) | 0.024 |
| Inflammation markers | ||||||
| IL-6, pg ml−1; median (IQR) | 1.40 (0.84−2.08) | 1.27 (0.78−1.90)* | 1.50 (0.88−2.80) | 1.45 (0.90−2.09) | 1.69 (0.95−2.45) | 0.019 |
| CRP, μg ml−1; median (IQR) | 2.60 (1.52−3.25) | 2.15 (1.13−4.54)* | 2.40 (1.24−5.48) | 3.91 (2.18−6.39) | 2.99 (1.93−8.48) | <0.0001 |
Abbreviations: CRP, c-reactive protein; IL, interleukin; IQR, interquartile range Q1–Q3; s.d., standard deviation.
Age and sex-adjusted differences in means, proportions and medians across low muscle strength and obesity categories were calculated using generalized linear models. Non-normally distributed continuous variables were ranked before significance examination.
Unable to walk 400 m or climb a flight of stairs without the help of another person.
Lung disease includes asthma, chronic bronchitis/emphysema.
Indicates significant (P < 0.05) difference between ‘Low muscle strength and obesity’ and other groups in pair wise comparisons.