Table 1.
Background characteristics, standard echocardiographic variables and myocardial concentrations of Q10 (total, reduced, oxidized), oxidation rate, CS activity and Q10/CS in control dogs and dogs with MMVD in different severities.
| CON | B1 | B2 | C | Overall p-Value | |
|---|---|---|---|---|---|
| N | 10 | 11 | 5 | 14 | |
| Breed CKCS/other |
0/10 | 11/0 | 5/0 | 14/0 | <0.0001 * |
| Sex Male/Female |
4/6 | 7/4 | 2/3 | 8/6 | 0.72 |
| Body weight (kg) | 27.5 (17.1–40.2) | 9.0 (8.1–10.1) a | 9.1 (9.0–9.9) a | 8.7 (7.9–11.4) a | <0.0001 * |
| BCS (1–9) | 5 (5–6) | 4 (4–5) | 5 (5–5) | 5 (4–5) | 0.14 |
| MR (no or mild/moderate/severe | 8/1/0 | 0/1/10 a | 0/0/5 a | 0/0/14 a | <0.0001 * |
| Murmur (1–6) | 0 (0–0) | 3 (2–3) a | 4 (4–5) a,b | 5 (4–5) a,b | <0.0001 * |
| Age (years) | 10.3 (4.0–11.8) | 10.8 (8.6–11.3) | 12.6 (12.6–12.7) | 10.01 (9.3–11.3) | 0.15 |
| LA/Ao | 1.3 (1.3–1.4) | 1.35 (1.3–1.4) | 2.0 (1.6–2.1) a,b | 2.75 (2.4–3.00) a,b,c | <0.0001 * |
| LVEDDN | 1.4 (1.30–1.60) | 1.6 (1.5–1.7) | 1.9 (1.9–2.1) a,b | 2.3 (1.9–2.6) a,b | <0.0001 * |
| FS (%) | 33.6 (33.0–38.8) | 35.5 (29.4–49.9) | 40.3 (39.8–43.2) | 45.4 (42.3–47.5) | 0.091 |
| Total Q10, myocardium, (µg/mg) |
2.8 (1.64–4.88) | 2.76 (2.10–4.81) | 3.85 (3.13–4.46) | 1.54 (1.36–1.94) a,b,c | 0.0035 * |
| Ubiquinone, myocardium, (µg/mg) |
0.97 (0.56–1.47) | 1.9 (0.82–2.08) | 1.2 (0.96–1.46) | 0.59 (0.44–0.66) a,b,c | 0.0008 * |
| Ubiquinol, myocardium, (µg/mg) |
1.84 (1.07–3.68) | 1.7 (1.06–2.73) | 2.89 (1.93–3.00) | 0.96 (0.76–1.33) a,b,c | 0.029 * |
| Oxidation rate (%) |
35.5 (32.4–42.3) | 42.2 (34.1–49.4) | 38.2 (32.7–38.3) | 36.6 (32.0–39.9) | 0.076 |
| CS μmol/g/min (n = 34) |
120.7 (109.6–138.5) n = 10 |
127.1 (121.8–130.7) n = 7 |
135.1 (121.9–135.5) n = 5 |
119.3 (111.95–128.3) n = 12 |
0.79 |
| Q10/CS | 0.017 (0.014–0.042) | 0.034 (0.014–0.044) | 0.033 (0.029–0.049) | 0.014 (0.0099–0.016) a,b,c | 0.0077 * |
Myocardial Q10 concentrations were successfully measured in included 40 dogs. CS activity was analyzed in 34 dogs while in the remaining dogs there was not sufficient tissue sample left for this analysis. Echocardiographic assessment of MR was missing for one dog (CON). Abbreviations: ACVIM: American College of Veterinary Internal Medicine; CS: citrate synthase; FS: Fractional Shortening; LA/Ao: Left atrial to aortic root ratio; LVEDDN: Left ventricular internal diameter in diastole normalized for body weight; MR: mitral regurgitation. Data are presented as median (interquartile range). N = 40 unless stated otherwise. * denotes statistically significant difference between groups. p-values were calculated using one-way ANOVA with post hoc t-test. Categorical parameters were tested using Fisher’s exact test. a: Different from CON, b: Different from B1, c: different from B2.