Table 2.
Meta-analysis of cross-sectional studies
| Outcome | Number of estimates | Number of physically active SCI individuals | Number of SCI individuals in control group | Mean difference (95% CI) | I2 for heterogeneity | Number of estimates | Mean difference (95% CI) (Para-athletes vs. control group) | I2 for heterogeneity | Number of estimates | Mean difference (95% CI) (Para-athletes excluded) |
I2 for heterogeneity |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Glucose homeostasis | |||||||||||
| Glucose, mg/dl | 10 | 166 | 286 | − 3.25 (− 5.36, − 1.14)* | 0% | 3 | − 3.43 (− 6.05, − 0.81)* | 0% | 7 | − 2.91 (− 6.48, 0.66) | 0% |
| HOMA-IR | 6 | 70 | 56 | − 0.22 (− 0.70, 0.26) | 45.1% | 0 | – | – | 6 | − 0.22 (− 0.70, 0.26) | 45.1% |
| Insulin, μU/ml | 7 | 86 | 132 | − 2.12 (− 4.21, − 0.03)* | 37.5% | 1 | – | – | 6 | − 2.41 (− 4.63, − 0.20) | 42.8% |
| Blood lipids | |||||||||||
| Total cholesterol, mg/dl | 10 | 129 | 312 | − 6.72 (− 13.09, − 0.34)* | 34.7% | 4 | − 11.8 (− 18.9, − 4.67)*1 | 12.2% | 6 | 0.93 (− 4.38, 6.23) | 0% |
| HDL, mg/dl | 12 | 181 | 358 | 3.86 (0.66, 7.05)* | 79.3%* | 6 | 4.87 (1.10, 8.65)* | 78.9%* | 6 | 2.44 (− 2.98,7.86) | 72.1%* |
| LDL, mg/dl | 9 | 141 | 214 | − 5.13 (− 12.2,1.91) | 28.8% | 3 | − 9.87 (− 19.1, − 0.65)* | 9.5% | 6 | − 0.33 (− 7.64, 6.98) | 0% |
| Triglycerides, mg/dl | 10 | 129 | 312 | − 3.21 (− 9.44, 3.03) | 18.5% | 4 | − 5.55 (− 11.8, 0.67) | 0% | 6 | − 3.28 (− 17.2,10.7) | 37.5% |
| Oxidative stress and inflammation | |||||||||||
| Catalase, UgHb−1 | 3 | 37 | 28 | 0.07 (0.03, 0.11)* | 0% | 1 | – | – | 2 | 1.86 (− 4.14, 7.87) | 0% |
| hsCRP, mg/dl | 4 | 53 | 44 | − 0.03 (− 0.10, 0.04) | 56.5% | 1 | – | – | 3 | − 0.02 (− 0.06, 0.02) | 11.2% |
| Atherosclerosis and vascular function | |||||||||||
| Carotid IMT, mm | 2 | 80 | 66 | − 0.09 (− 0.16, − 0.02) | 68.7% | 1 | – | – | 1 | – | – |
| Blood pressure and heart rate | |||||||||||
| Systolic blood pressure, mmHg | 9 | 212 | 268 | − 2.31 (− 6.68, 2.06) | 36.8% | 4 | 1.21 (− 3.63, 6.05) | 0% | 5 | − 5.08 (− 11.80, 1.64) | 44.9% |
| Diastolic blood pressure, mmHg | 8 | 157 | 218 | − 1.99 (− 5.47,1.50) | 37.9% | 4 | 0.93 (− 2.90, 4.75) | 0% | 4 | − 4.92 (− 9.60, − 0.24)* | 29.6% |
| Resting Heart rate, bpm | 7 | 122 | 103 | − 6.93 (− 11.22, − 2.65)* | 46.7% | 4 | − 7.59 (− 11.12, − 4.05)* | 0.0% | 3 | − 3.58 (− 17.99,10.82) | 81.3%* |
| Cardiac structure | |||||||||||
| Aortic root diameter, mm | 3 | 37 | 38 | 1.00 (− 0.65, 2.65) | 0% | 2 | 1.01 (− 0.65, 2.68) | 0% | 1 | – | – |
| LV end diastolic diameter, mm | 3 | 39 | 36 | 3.24 (1.06, 5.43)* | 23.2% | 2 | 2.89 (0.15, 5.62)* | 45.9% | 1 | – | – |
| Posterior wall thickness, mm | 4 | 47 | 45 | 0.02 (− 0.71, 0.75) | 76.6%* | 2 | − 0.04 (− 0.42,0.35) | 19.4% | 2 | 0.09 (− 2.46, 2.64) | 91.4%* |
| Septal wall thickness, mm | 5 | 72 | 55 | − 0.13 (− 0.95, 0.69) | 82.4%* | 3 | − 0.49 (− 1.06, 0.08) | 57.4% | 2 | 0.49 (− 1.76, 2.74) | 88.4%* |
| LV mass index, g/m2 | 4 | 47 | 45 | 6.57 (− 8.42, 21.56) | 86.6%* | 2 | 7.58 (− 0.07,15.2) | 0% | 2 | 6.97 (− 30.5, 44.5) | 94.2%* |
| End diastolic volume, ml | 2 | 18 | 16 | − 2.41 (− 14.44, 9.61) | 0% | 0 | – | – | 2 | − 2.41 (− 14.4, 9.61) | 0% |
| Global systolic and diastolic function | |||||||||||
| Stroke volume, ml | 4 | 66 | 58 | 9.37 (3.07, 15.66)* | 46.2% | 3 | 11.35 (4.04,18.67)* | 43.9% | 1 | – | – |
| Cardiac output, Q, L/min | 3 | 37 | 38 | − 0.04 (− 0.62, 0.53) | 0% | 2 | 0.04 (− 0.62, 0.71) | 0% | 1 | – | – |
| Ejection fraction, % | 5 | 76 | 65 | − 0.85 (− 2.66, 0.97) | 0% | 3 | − 1.14 (− 3.12, 0.83) | 0% | 2 | 0.77 (− 3.86, 5.40) | 0% |
| E/A ratio | 4 | 47 | 45 | 0.18 (− 0.07, 0.44) | 44.9% | 2 | 0.10 (− 0.13, 0.33) | 0% | 2 | 0.24 (− 0.41, 0.89) | 70.8% |
| Isovolumetric relaxation time, ms | 2 | 18 | 16 | − 11.70 (− 19.50, − 3.89)* | 0% | 0 | – | – | 2 | − 11.70 (− 19.50, − 3.89)* | 0% |
| Cardiorespiratory fitness | |||||||||||
| Relative VO2, ml/kg/min | 10 | 133 | 102 | 8.52 (5.52, 11.52) * | 85.5% | 2 | 12.25 (7.78, 16.71) * | 56.7% | 8 | 7.48 (4.10, 10.86)* | 84.7% |
| Absolute VO2, L/min | 4 | 42 | 42 | 0.81 (0.46, 1.15)* | 85.3% | – | – | – | 4 | 0.81 (0.46, 1.15)* | 85.3% |
| Peak workload, W | 5 | 72 | 61 | 53.23 (36.66, 69.80)* | 78.7% | 1 | – | – | 4 | 58.09 (36.40, 79.79)* | 78.9% |
| Peak Heart Rate, bpm | 6 | 84 | 70 | 8.49 (0.06, 16.91) * | 77.9% | 1 | – | – | 5 | 8.49 (0.06, 16.91)* | 59.2% |
*Indicates statistically significant results
1p value from meta-regression was significant
HOMA-IR: Homeostatic Model Assessment for Insulin Resistance; HDL: High-density lipoprotein: LDL: Low density lipoprotein; hsCRP: High-sensitivity C-reactive protein; LV: Left ventricular…;
E/A ratio: Early to late ventricular filling ratio; VO2: Maximal oxygen consumption
Physically active group definition was heterogeneous among the studies. The studies included in current review were published between 1975 and 2019. Considering that physical activity recommendations varied over these four decades, we considered that physical activity guidelines recommendations were met or exceeded in the following cases: 1. Individuals in physically active group were engaged in at least 30 min of moderate to vigorous intensity aerobic exercise 3 times per week (90 min/week); conditional SCI-specific recommendation that this physical activity level could improve cardiometabolic health in SCI individuals [29] OR. 2. At least 20 min of moderate to vigorous intensity aerobic exercise twice per week and three sets of strength exercise for each major functioning muscle group at a moderate to vigorous intensity two times per week (linked with improved cardiorespiratory fitness in SCI) [29] OR. 3. Individuals in physically active group engaged in moderate to vigorous physical activity at the frequency of minimum twice per week in duration of 20–30 min OR any sustained physical activity can be of benefit to CVD health in SCI population as long as it meets the requirements for time and intensity [27]. OR. 4. Moderate leisure time physical activity (LTPA) ≥ 150 min/week or vigorous LTPA ≥ 60 min/week, based on ACSM/AHA recommendations (the SCI-specific recommendations were not available) [41] OR. 4. Professional para-athletes were considered to meet physical activity recommendations due to professional component in their engagement in sports. Details can be found in Supplemental Table 1 and “Methods” section