Table 1.
Characteristics of participants at baseline
| Characteristics | Systemic inflammation subcohort (N = 393 443) | Frailty phenotype subcohort (N = 390 485) | P value a | ||
|---|---|---|---|---|---|
| Non‐frail (N = 142 960) | Pre‐frail (N = 221 552) | Frail (N = 25 973) | |||
| Incident OP cases (%) | 12 722 (3.23) | 3892 (2.72) | 7070 (3.19) | 1537 (5.92) | <0.001 |
| Systemic inflammation markers, median (IQR) | |||||
| SII | 528.08 (392.10, 714.00) | ||||
| NLR | 2.14 (1.67, 2.77) | ||||
| PLR | 132.50 (105.68, 166.67) | ||||
| Age (years), mean ± SD | 56.05 ± 8.08 | 56.49 ± 8.06 | 55.65 ± 8.09 | 56.64 ± 7.88 | <0.001 |
| Townsend deprivation index, mean ± SD | −1.37 ± 3.04 | −1.69 ± 2.87 | −1.35 ± 3.03 | −0.25 ± 3.42 | <0.001 |
| Female (%) | 203 686 (51.77) | 65 410 (45.75) | 121 053 (54.64) | 16 485 (63.47) | <0.001 |
| BMI (%) | <0.001 | ||||
| Normal | 124 184 (31.56) | 56 630 (39.61) | 63 620 (28.72) | 3190 (12.28) | |
| Underweight | 1839 (0.47) | 805 (0.56) | 934 (0.42) | 83 (0.32) | |
| Overweight | 168 952 (42.94) | 61 597 (43.09) | 96 985 (43.78) | 9119 (35.11) | |
| Obese | 98 468 (25.03) | 23 928 (16.74) | 60 013 (27.09) | 13 581 (52.29) | |
| Ethnicity (%) | <0.001 | ||||
| Non‐White/European ethnicity | 17 993 (4.57) | 4555 (3.19) | 10 524 (4.75) | 2166 (8.34) | |
| White/European ethnicity | 375 450 (95.43) | 138 405 (96.81) | 211 028 (95.25) | 23 807 (91.66) | |
| Physical activity level (%) | <0.001 | ||||
| Low | 62 023 (18.76) | 14 909 (12.06) | 38 271 (20.45) | 8485 (41.77) | |
| Moderate | 135 353 (40.95) | 48 056 (38.87) | 80 129 (42.81) | 7648 (37.65) | |
| High | 133 192 (40.29) | 60 682 (49.08) | 68 783 (36.75) | 4180 (20.58) | |
| Annual household income (%) | <0.001 | ||||
| Less than £18 000 | 86 884 (22.08) | 25 416 (17.78) | 47 761 (21.56) | 10 789 (41.54) | |
| £18 000 to £30 999 | 99 678 (25.33) | 36 739 (25.70) | 55 295 (24.96) | 6528 (25.13) | |
| £31 000 to £51 999 | 103 720 (26.36) | 39 666 (27.75) | 58 866 (26.57) | 5158 (19.86) | |
| £52 000 to £100 000 | 81 423 (20.69) | 31 890 (22.31) | 47 361 (21.38) | 2939 (11.32) | |
| Greater than £100 000 | 21 738 (5.53) | 9249 (6.47) | 12 269 (5.54) | 559 (2.15) | |
| Education level (%) | <0.001 | ||||
| No qualification | 57 497 (14.61) | 17 683 (12.37) | 30 931 (13.96) | 6784 (26.12) | |
| Other qualification | 197 341 (50.16) | 70 732 (49.48) | 112 058 (50.58) | 13 117 (50.50) | |
| College/university degree | 138 605 (35.23) | 54 545 (38.15) | 78 563 (35.46) | 6072 (23.38) | |
| Nutrient and mineral supplementation (%) | 40 172 (10.21) | 13 902 (9.72) | 23 128 (10.44) | 3016 (11.61) | <0.001 |
| Drinking (%) | <0.001 | ||||
| Never | 14 480 (3.68) | 4143 (2.90) | 8071 (3.64) | 1801 (6.93) | |
| Previous | 13 255 (3.37) | 3716 (2.60) | 7229 (3.26) | 1924 (7.41) | |
| Current | 365 708 (92.95) | 135 101 (94.50) | 206 252 (93.09) | 22 248 (85.66) | |
| Smoking (%) | <0.001 | ||||
| Never | 214 210 (54.44) | 79 469 (55.59) | 121 061 (54.64) | 12 385 (47.68) | |
| Previous | 137 927 (35.06) | 50 126 (35.06) | 77 304 (34.89) | 9564 (36.82) | |
| Current | 41 306 (10.50) | 13 365 (9.35) | 23 187 (10.47) | 4024 (15.49) | |
Abbreviations: BMI, body mass index; IQR, interquartile range; NLR, neutrophil‐to‐lymphocyte ratio; OP, osteoporosis; PLR, platelet‐to‐lymphocyte ratio; SD, standard deviation; SII, systemic immune‐inflammation index.
a
Baseline characteristics were compared between frailty status using analysis of variance, Kruskal–Wallis rank sum and χ 2 tests, as appropriate.