Table 6.
Demographic, clinical, body composition and medication variables stratified by frailty category based on the Fried Frailty Index (Fried et al., 2001).
| Variables | Robust (n = 27)f | Pre-frail (n = 97)f | Frail (n = 14)f | p-Valueg |
|---|---|---|---|---|
| Demographics | ||||
| Age | 54.3 ± 11.5 | 58.8 ± 10.8 | 59.1 ± 9.2 | 0.143 |
| Female sex | 19 (70%) | 85 (88%) | 13 (93%) | 0.059 |
| White race | 23 (85%) | 76 (78%) | 8 (57%) | 0.117 |
| Disease characteristics | ||||
| RF positive | 16 (59%) | 70 (72%) | 10 (71%) | 0.430 |
| High positive anti-CCPa | 10 (37%) | 57 (59%) | 9 (64%) | 0.093 |
| Disease duration (years) | 15.7 ± 9.0 | 20.0 ± 11.4 | 18.5 ± 9.7 | 0.186 |
| Current smoker | 1 (4%) | 6 (6%) | 1 (7%) | 0.865 |
| RADAI score | 1.6 ± 1.2 | 2.7 ± 1.7 | 4.0 ± 1.7 | <0.001 |
| ESR (median, IQR) | 9.0 (4–15) | 14.5 (4–28) | 20.5 (13−32) | 0.029 |
| CRP (median, IQR) | 1.2 (0.6–3.1) | 1.8 (0.7–4.9) | 4.8 (1.6–12.3) | 0.035 |
| Body composition | ||||
| BMI (kg/m2) | 24.9 ± 3.3 | 27.2 ± 5.8 | 31.6 ± 9.0 | 0.003 |
| FMI (kg/m2) | 8.3 ± 2.1 | 10.9 ± 4.4 | 14.7 ± 6.0 | <0.0001 |
| DXA obeseb | 8 (30%) | 61 (63%) | 12 (86%) | 0.001 |
| Appendicular LMI (kg/m2) | 6.8 ± 1.2 | 6.3 ± 1.1 | 6.4 ± 1.7 | 0.260 |
| Femoral neck BMD (g/cm2) | 0.964 ± 0.163 | 0.863 ± 0.123 | 0.865 ± 0.104 | 0.002 |
| Low BMDc | 3 (11%) | 18 (19%) | 2 (14%) | 0.623 |
| Very low BMDc | 0 | 2 (2%) | 0 | 0.804 |
| Medications | ||||
| Subjects on prednisone | 4 (15%) | 33 (34%) | 7 (50%) | 0.051 |
| Mean dose among those reporting use (mg/day) | 3.4 ± 1.4 | 6.5 ± 4.4 | 11.9 ± 11.1 | 0.040 |
| TNF inhibitor | 13 (48%) | 45 (46%) | 5 (36%) | 0.724 |
| Osteoporosis medicationd, e | 3 (12%) | 24 (29%) | 4 (50%) | 0.076 |
RF: rheumatoid factor; CCP: cyclic citrullinated peptide antibody; RADAI: rheumatoid arthritis disease activity index; ESR: erythrocyte sedimentation rate; CRP: high-sensitivity c-reactive protein; BMI: body mass index; FMI: fat mass index; DXA: dual x-ray absorptiometry; LMI: lean mass index; BMD: bone mineral density; TNF: tumor necrosis factor.
High positive anti-CCP defined as level three times the upper limit of normal (>60 units) based on the 2010 EULAR/ACR RA classification criteria (Aletaha et al., 2010). This threshold was used to minimize heterogeneity of this group.
DXA obese was defined using % body fat from DXA based on age, sex, and race-specific criteria.
Low BMD was defined as a Z-score ≤−1.0 and very low BMD was defined as a Z-score ≤−2.0 at the femoral neck.
Osteoporosis medications represent bisphosphonate use. One patient self-reported estrogen use, but was also taking bisphosphonates. No subjects recorded use of parathyroid hormone, raloxifene or calcitonin.
n = 117. Due to differences in interview protocols, this question was not asked of all participants.
Frailty category as defined by Fried Frailty Index (Fried et al., 2001) (1 point for each component. Score of 0 = robust; 1–2 = pre-frail; 3+ = frail). Low weight was based on BMI. Exhaustion was based on patient self-report. Low gait speed is based on the 4-meter walking speed test. Low grip strength is measured by hand-held dynamometer. Low physical activity was based on the International Physical Activity Questionnaire (Giles et al., 2008a).
p-Value refers to the difference between the three frailty groups. One-way ANOVA was performed for all variables except for tests of medians where Kruskal-Wallis test was performed.