Introduction
Material and methods
Study design and population
Preoperative CHO loading and water-only fasting protocol
Outcomes
Covariates
Statistical analysis
Characteristics | Before matching | After matching | ||||||
---|---|---|---|---|---|---|---|---|
Control | CHO | Standardized differencea | P-value | Control | CHO | Standardized differencea | P-value | |
(N = 608) | (N = 271) | (N = 264) | (N = 264) | |||||
Mean (SD) Median (Q1–Q3)/N (%) | Mean (SD) Median (Q1–Q3)/N (%) | |||||||
Age | 69.90 (11.63) 70.00 (61.00–79.00) | 74.75 (9.76) 74.00 (67.00–82.00) | 0.45 (0.31, 0.60) | < 0.001 | 75.76 (10.43) 76.50 (68.00–84.00) | 74.45 (9.62) 73.50 (66.00–82.00) | 0.13 (− 0.04, 0.30) | 0.135 |
BMI | 22.95 (3.38) 22.86 (20.75–25.13) | 23.11 (3.41) 23.01 (20.52–25.39) | 0.05 (− 0.09, 0.19) | 0.506 | 22.75 (3.49) 22.49 (20.28–25.26) | 23.06 (3.41) 22.86 (20.49–25.35) | 0.09 (− 0.08, 0.26) | 0.305 |
Serum sodium, mmol/L | 140.66 (2.73) 140.80 (139.10–142.40) | 140.85 (3.01) 140.90 (139.10–142.75) | 0.07 (− 0.08, 0.21) | 0.349 | 140.58 (2.88) 140.85 (139.00–142.40) | 140.89 (2.98) 140.90 (139.10–142.70) | 0.10 (− 0.07, 0.27) | 0.234 |
Serum potassium, mmol/L | 3.89 (0.45) 3.89 (3.60–4.13) | 3.87 (0.43) 3.87 (3.60–4.08) | 0.04 (− 0.10, 0.18) | 0.604 | 3.91 (0.45) 3.92 (3.65–4.15) | 3.86 (0.41) 3.87 (3.60–4.08) | 0.11 (− 0.06, 0.28) | 0.202 |
Serum calcium, mmol/L | 2.20 (0.13) 2.20 (2.12–2.29) | 2.20 (0.12) 2.21 (2.13–2.27) | 0.02 (− 0.13, 0.16) | 0.818 | 2.20 (0.14) 2.21 (2.12–2.29) | 2.20 (0.12) 2.21 (2.13–2.27) | 0.01 (− 0.16, 0.18) | 0.905 |
Serum magnesium, mmol/L | 0.89 (0.10) 0.89 (0.82–0.95) | 0.88 (0.11) 0.89 (0.82–0.95) | 0.05 (− 0.09, 0.19) | 0.489 | 0.88 (0.10) 0.88 (0.82–0.95) | 0.88 (0.11) 0.89 (0.82–0.95) | 0.01 (− 0.16, 0.18) | 0.928 |
Serum phosphate, mmol/L | 1.07 (0.21) 1.07 (0.94–1.20) | 1.07 (0.19) 1.06 (0.95–1.19) | 0.04 (− 0.11, 0.18) | 0.61 | 1.09 (0.21) 1.10 (0.96–1.21) | 1.07 (0.19) 1.06 (0.95–1.19) | 0.12 (− 0.05, 0.29) | 0.184 |
Hemoglobin, g/L | 126.12 (20.31) 129.00 (114.50–141.00) | 124.70 (18.35) 127.00 (113.10–138.80) | 0.07 (− 0.07, 0.22) | 0.322 | 125.74 (21.37) 129.00 (113.00–141.00) | 124.88 (17.85) 127.00 (113.80–138.00) | 0.04 (− 0.13, 0.21) | 0.618 |
Platelet count, × 109/L | 175.98 (64.45) 166.00 (136.00–211.00) | 177.50 (69.59) 166.00 (130.00–214.95) | 0.02 (− 0.12, 0.17) | 0.754 | 171.61 (61.97) 162.00 (134.00–205.00) | 178.20 (70.02) 166.50 (130.00–215.00) | 0.10 (− 0.07, 0.27) | 0.253 |
Fasting blood glucose, mmol/L | 5.45 (0.73) 5.51 (5.05–5.89) | 5.47 (0.73) 5.60 (5.08–5.90) | 0.03 (− 0.11, 0.18) | 0.662 | 5.45 (0.71) 5.50 (5.05–5.92) | 5.47 (0.73) 5.59 (5.07–5.90) | 0.03 (− 0.14, 0.20) | 0.748 |
Serum albumin, g/L | 39.93 (4.47) 40.10 (37.08–42.92) | 39.72 (3.88) 40.10 (37.40–42.20) | 0.05 (− 0.09, 0.20) | 0.488 | 39.95 (4.52) 40.20 (36.80–42.92) | 39.68 (3.87) 40.10 (37.30–42.20) | 0.06 (− 0.11, 0.23) | 0.461 |
Neutrophil count, × 109/L | 6.55 (3.15) 5.88 (4.30–8.00) | 6.57 (2.82) 6.10 (4.56–8.26) | 0.01 (− 0.14, 0.15) | 0.917 | 6.56 (3.19) 5.90 (4.40–8.00) | 6.53 (2.77) 6.05 (4.51–8.23) | 0.01 (− 0.16, 0.18) | 0.918 |
Lymphocyte count, × 109/L | 1.26 (0.53) 1.20 (0.90–1.60) | 1.25 (0.56) 1.20 (0.90–1.53) | 0.02 (− 0.13, 0.16) | 0.801 | 1.28 (0.52) 1.20 (0.90–1.60) | 1.26 (0.57) 1.20 (0.90–1.56) | 0.05 (− 0.12, 0.22) | 0.576 |
Monocyte count, × 109/L | 0.55 (0.49) 0.50 (0.40–0.70) | 0.52 (0.27) 0.50 (0.38–0.63) | 0.07 (− 0.07, 0.22) | 0.366 | 0.51 (0.25) 0.48 (0.35–0.64) | 0.52 (0.27) 0.50 (0.40–0.63) | 0.02 (− 0.15, 0.19) | 0.783 |
ALT, U/L | 23.94 (21.53) 20.00 (14.00–28.00) | 23.61 (16.96) 19.00 (15.00–26.00) | 0.02 (− 0.13, 0.16) | 0.824 | 25.35 (27.76) 20.00 (14.75–28.00) | 23.46 (16.90) 19.00 (15.00–26.00) | 0.08 (− 0.09, 0.25) | 0.345 |
AST, U/L | 26.25 (19.58) 23.00 (18.00–29.00) | 25.59 (16.30) 22.00 (19.00–27.50) | 0.04 (− 0.11, 0.18) | 0.629 | 27.12 (26.02) 23.00 (18.00–29.00) | 25.38 (15.79) 22.00 (19.00–27.25) | 0.08 (− 0.09, 0.25) | 0.355 |
Serum creatinine, μmol/L | 66.98 (22.92) 63.00 (54.00–76.00) | 67.30 (22.69) 64.00 (55.00–76.00) | 0.01 (− 0.13, 0.16) | 0.845 | 68.91 (24.80) 65.00 (55.00–78.00) | 66.31 (19.70) 63.00 (54.75–74.25) | 0.12 (− 0.05, 0.29) | 0.182 |
Serum urea nitrogen, mmol/L | 6.08 (2.32) 5.60 (4.61–6.90) | 5.95 (2.30) 5.60 (4.48–6.82) | 0.06 (− 0.09, 0.20) | 0.441 | 6.22 (2.45) 5.70 (4.80–7.10) | 5.87 (2.11) 5.57 (4.45–6.80) | 0.15 (− 0.02, 0.32) | 0.081 |
Serum uric acid, μmol/L | 286.99 (91.67) 282.00 (223.25–344.00) | 286.14 (87.16) 276.00 (232.50–332.00) | 0.01 (− 0.13, 0.15) | 0.898 | 287.37 (90.65) 282.00 (222.50–342.00) | 283.92 (85.93) 275.50 (229.75–328.00) | 0.04 (− 0.13, 0.21) | 0.654 |
Sex | 0.19 (0.04, 0.33) | 0.01 | 0.02 (− 0.16, 0.19) | 0.858 | ||||
Female | 422 (69.41%) | 164 (60.52%) | 161 (60.98%) | 163 (61.74%) | ||||
Male | 186 (30.59%) | 107 (39.48%) | 103 (39.02%) | 101 (38.26%) | ||||
Smoking | 0.03 (− 0.11, 0.17) | 0.683 | 0.01 (− 0.16, 0.18) | 0.874 | ||||
No | 557 (91.61%) | 246 (90.77%) | 243 (92.05%) | 242 (91.67%) | ||||
Yes | 51 (8.39%) | 25 (9.23%) | 21 (7.95%) | 22 (8.33%) | ||||
Drinking | 0.10 (− 0.04, 0.25) | 0.143 | 0.00 (− 0.17, 0.17) | 1 | ||||
No | 580 (95.39%) | 252 (92.99%) | 247 (93.56%) | 247 (93.56%) | ||||
Yes | 28 (4.61%) | 19 (7.01%) | 17 (6.44%) | 17 (6.44%) | ||||
Fracture site | 0.19 (0.05, 0.34) | 0.069 | 0.21 (0.04, 0.38) | 0.115 | ||||
Spine | 288 (47.37%) | 107 (39.48%) | 98 (37.12%) | 107 (40.53%) | ||||
Hip | 230 (37.83%) | 107 (39.48%) | 128 (48.48%) | 103 (39.02%) | ||||
Proximal humerus | 17 (2.80%) | 11 (4.06%) | 7 (2.65%) | 11 (4.17%) | ||||
Wrist | 73 (12.01%) | 46 (16.97%) | 31 (11.74%) | 43 (16.29%) | ||||
ASA score | 0.19 (0.04, 0.33) | 0.031 | 0.14 (− 0.03, 0.31) | 0.282 | ||||
1 | 93 (15.30%) | 38 (14.02%) | 31 (11.74%) | 38 (14.39%) | ||||
2 | 432 (71.05%) | 177 (65.31%) | 189 (71.59%) | 172 (65.15%) | ||||
3 | 83 (13.65%) | 56 (20.66%) | 44 (16.67%) | 54 (20.45%) | ||||
CCI | 0.15 (0.01, 0.29) | 0.17 | 0.07 (− 0.10, 0.24) | 0.735 | ||||
0 | 533 (87.66%) | 244 (90.04%) | 242 (91.67%) | 237 (89.77%) | ||||
1 | 55 (9.05%) | 24 (8.86%) | 20 (7.58%) | 24 (9.09%) | ||||
2 | 20 (3.29%) | 3 (1.11%) | 2 (0.76%) | 3 (1.14%) | ||||
Prior fracture | 0.19 (0.05, 0.33) | 0.012 | 0.02 (− 0.15, 0.19) | 0.806 | ||||
No | 479 (78.78%) | 233 (85.98%) | 224 (84.85%) | 226 (85.61%) | ||||
Yes | 129 (21.22%) | 38 (14.02%) | 40 (15.15%) | 38 (14.39%) | ||||
Anesthesia | 0.19 (0.05, 0.34) | 0.03 | 0.15 (− 0.02, 0.32) | 0.229 | ||||
General anesthesia | 322 (52.96%) | 118 (43.54%) | 119 (45.08%) | 117 (44.32%) | ||||
Spinal anesthesia | 195 (32.07%) | 100 (36.90%) | 108 (40.91%) | 96 (36.36%) | ||||
Brachial plexus block anesthesia | 91 (14.97%) | 53 (19.56%) | 37 (14.02%) | 51 (19.32%) | ||||
Hypertension | 0.04 (− 0.10, 0.18) | 0.569 | 0.01 (− 0.16, 0.18) | 0.924 | ||||
No | 410 (67.43%) | 188 (69.37%) | 184 (69.70%) | 185 (70.08%) | ||||
Yes | 198 (32.57%) | 83 (30.63%) | 80 (30.30%) | 79 (29.92%) |
Results
Patient baseline features
Primary outcome
Outcomes | Model 1a | Model 2b | Model 3c |
---|---|---|---|
Mortality, OR (95% CI) P-value | 0.35 (0.15, 0.85) 0.020 | 0.37 (0.14, 0.97) 0.044 | 0.34 (0.12, 0.95) 0.039 |
LOS, β (95% CI) P-value, days | − 1.65 (− 2.42, − 0.88) < 0.001 | − 1.44 (− 2.19, − 0.69) < 0.001 | − 1.36 (− 2.11, − 0.61) < 0.001 |
Hospitalization cost, β (95% CI) P-value, U$ | − 543.26 (− 909.74, − 176.78) 0.004 | − 543.26 (− 909.74, − 176.78) 0.004 | − 504.42 (− 872.49, − 136.35) 0.008 |
Blood transfusion, OR (95% CI) P-value | 0.60 (0.32, 1.14) 0.118 | 0.82 (0.41, 1.63) 0.564 | 0.84 (0.42, 1.69) 0.627 |
PONV, OR (95% CI) P-value | 1.00 (0.35, 2.89) 1.000 | 1.22 (0.41, 3.62) 0.721 | 1.10 (0.36, 3.31) 0.870 |
Secondary outcomes
Subgroup analyses
Subgroup | N | OR (95% CI) P-value | P-value for interaction |
---|---|---|---|
Sex | 0.97 | ||
Female | 324 | 0.30 (0.05, 1.65) 0.1650 | |
Male | 204 | 0.28 (0.07, 1.22) 0.0911 | |
Age tertile | 0.61 | ||
Low | 159 | 0.00 (0.00, Inf) 0.9998 | |
Middle | 180 | 110.06 (0.00, Inf) 0.9999 | |
High | 189 | 0.27 (0.09, 0.86) 0.0266 | |
BMI tertile | 0.06 | ||
Low | 175 | 0.87 (0.22, 3.48) 0.8412 | |
Middle | 177 | 0.03 (0.00, 0.55) 0.0177 | |
High | 176 | 0.00 (0.00, Inf) 0.9985 | |
Fracture site | 0.78 | ||
Spine | 205 | 0.03 (0.00, 5.20) 0.1800 | |
Hip | 231 | 0.32 (0.10, 0.99) 0.0475 | |
Proximal humerus | 18 | 1.00 (0.00, Inf) 1.0000 | |
Wrist | 74 | 1.00 (0.00, Inf) 1.0000 | |
Anesthesia | 0.95 | ||
General anesthesia | 236 | 0.41 (0.06, 3.00) 0.3792 | |
Spinal anesthesia | 204 | 0.28 (0.08, 1.00) 0.0499 | |
Brachial plexus block anesthesia | 88 | 1.00 (0.00, Inf) 1.0000 | |
Potassium tertile | 0.36 | ||
Low | 174 | inf. (0.00, Inf) 0.9930 | |
Middle | 173 | 0.07 (0.01, 0.73) 0.0265 | |
High | 181 | 0.53 (0.09, 3.08) 0.4831 | |
Magnesium tertile | 0.56 | ||
Low | 163 | 0.37 (0.01, 10.62) 0.5613 | |
Middle | 184 | 0.03 (0.00, 3.91) 0.1624 | |
High | 181 | 0.36 (0.09, 1.43) 0.1444 | |
Serum creatinine tertile | 0.16 | ||
Low | 176 | 0.66 (0.19, 2.37) 0.5268 | |
Middle | 172 | 0.00 (0.00, Inf) 0.9808 | |
High | 180 | 0.00 (0.00, Inf) 0.9948 |