Table 2.
Characteristics associated with higher mitochondrial DNA copy number among people with PAD (n=34).a
| Tertile 1 MtDNA 249–559 arbitrary units (n=ll) |
Tertile 2 MtDNA 606–874 arbitrary units (n=l2) |
Tertile 3 MtDNA 908-1540 arbitrary units (n=ll) |
Trend p-value | |
|---|---|---|---|---|
| Age, years | 75.5 (6.9) | 73.9 (7.8) | 7l.20 (3.l) | 0.ll |
| Male | 9 (8l.8) | 8 (66.7) | 7 (63.6) | 0.35 |
| African American race | 7 (63.6) | 6 (50.0) | 6 (54.6) | 0.67 |
| Current smoker | 1 (9.l) | 5 (4l.7) | 3 (27.3) | 0.33 |
| Former smoker | 7 (63.6) | 5 (4l.7) | 7 (63.6) | l.00 |
| Ankle-brachial index | 0.72 (0.l5) | 0.72 (0.l3) | 0.56 (0.l4) | 0.0ll |
| Body mass index, kg/m2 | 28.48 (3.30) | 30.50 (2.36) | 29.67 (5.8l) | 0.50 |
| Diabetes | 6 (54.6) | 5 (4l.7) | 4 (36.4) | 0.39 |
| Myocardial infarction | 0 (0.00) | 0 (0.00) | l (9.09) | 0.2l |
| Angina | 1 (9.l) | 1 (8.3) | 2 (l8.2) | 0.5l |
| Pulmonary disease | 2 (l8.2) | 2 (l6.7) | 2 (l8.2) | l.00 |
| Cancer | 3 (27.3) | 2 (l6.7) | 6 (54.6) | 0.l7 |
| Six-minute walk, feet | l282.2 (l96.5) | ll69.7 (220.0) | ll2l.8 (240.6) | 0.09 |
| Usual paced 4-meter walking velocity, m/s | 0.83 (0.l5) | 0.82 (0.l3) | 0.79 (0.l6) | 0.5l |
| Fast paced 4-meter walking velocity, m/s | l.ll (0.24) | l.l5 (0.24) | l.l0 (0.20) | 0.90 |
| Relative COX enzyme activityb | 59.ll (28.8l) | l07.40 (59.02) | ll8.56 (58.02) | 0.0l8 |
| PGC-1 quantity, arbitrary units | 3.ll (8.8l) | 0.46 (0.87) | l.09 (l.47) | 0.38 |
| Relative citrate synthase enzymenb | l07.59 (l6.47) | l04.40 (8.82) | 99.66 (l9.59) | 0.24 |
MtDNA, mitochondrial DNA; PAD, peripheral artery disease.
Data shown for continuous variables are means and standard deviations. Categorical variables are presented as n (%). The test for trend was assessed using linear regression and by entering the tertiles as ‘1, 2, 3’ in a linear regression model.
a
MtDNA copy number is measured relative to nuclear DNA and is expressed as arbitrary units.
b
COX and citrate synthase enzyme activity were measured in batches and results are reported relative to a standard sample run within each batch to allow comparison of results from different batches.