Table 5.
Calf muscle area and functional outcomes among persons with peripheral arterial disease.
| Tertile 1 (lowest calf muscle area) |
Tertile 2 | Tertile 3 (highest calf muscle area) |
Trend P value | |
|---|---|---|---|---|
| MOBILITY LOSS (n=331) | ||||
| Tertile Definition** | 0.073–0.194 | >0.194–0.215 | >0.215–0.293 | |
| Number of participants | N=110 | N=111 | N=110 | |
| Number with mobility loss | N=28 | N=10 | N=11 | |
| Model 1 | 2.53 (1.18 – 5.40)1 | 0.74 (0.30 – 1.80) | 1.0 (Reference) | 0.005 |
| Model 2 | 3.29 (1.40 – 7.73)2 | 0.90 (0.35 – 2.32) | 1.0 (Reference) | 0.004 |
| Model 3 | 2.45 (0.98 – 6.13) | 0.70 (0.26 – 1.86) | 1.0 (Reference) | 0.023 |
| Model 4 | 2.46(0.97–6.24) | 0.74 (0.27–2.00) | 1.0 (Reference) | 0.039 |
| BECOMING UNABLE TO WALK FOR SIX MINUTES CONTINUOUSLY (n=236) | ||||
| Tertile Definition** | 0.072–0.194 | >0.194–0.213 | 0.214–0.275 | |
| Number of participants | N=78 | N=79 | N=79 | |
| Number who stopped during the six-minute walk at follow-up. | N=21 | N=15 | N=18 | |
| Model 1 | 1.04 (0.51 – 2.11) | 0.64 (0.30 – 1.34) | 1.0 (Reference) | 0.66 |
| Model 2 | 1.67 (0.74 – 3.79) | 0.95 (0.43 – 2.11) | 1.0 (Reference) | 0.086 |
| Model 3 | 1.47 (0.63 – 3.43) | 0.84 (0.37 – 1.90) | 1.0 (Reference) | 0.14 |
| Model 4 | 1.46 (0.61–3.47) | 0.83 (0.36–1.89) | 1.0 (Reference) | 0.15 |
Data shown are hazard ratios (95% confidence intervals). Model 1 adjusts for age, sex, and race. Model 2 adjusts for variables in Model 1 and the ankle brachial index, body mass index, smoking, and comorbidities. Model 3 adjusts for covariates in Model 2 and physical activity level. Model 4 adjusts for covariates in Model 3 and time-dependent use of statin, cilostazol, and pentoxifylline use.
The reference group is the tertile with lowest baseline calf muscle area.
Analyses for mobility loss exclude participants with mobility limitations at baseline. Analyses for becoming unable to walk for six-minutes continuously exclude participants who stopped during the six-minute walk test at baseline. Because of sample size differences for each outcome, tertile definitions are distinct for each outcome.
P=0.017 relative to reference;
P=0.006 relative to reference
Tertiles represent standardized tertiles adjusted for tibia length. Muscle area values corresponding to the standardized tertiles are as follows: For mobility loss- 1st standardized tertile- 648–7331 mm2; 2nd standardized tertile- 3,816–7,894 mm2; 3rd standardized tertile- 4,528–9,820 mm2. For becoming unable to walk for six-minutes continuously: 1st standardized tertile- 601.2–6,795 mm2; 2nd standardized tertile- 3,645–7,488 mm2; 3rd standardized tertile- 4,528–9,819 mm2.