Table 2.
Study Characteristics
| Study | Country | Study design | Type of surgery | Sample size, n | HbA1c cut-off (no. of patients, percentage) | Time window between HbA1c level result and surgery | Outcome measures |
|---|---|---|---|---|---|---|---|
| Lee et al. 2015 [31] | South Korea | Retrospective | Nephrectomy (radical and partial) for renal cell carcinoma | n = 3075 | ≥ 6.8% (n = 158, 50%) | Within 6 months of the surgery | · Progression-free survival |
| 316 (75.8%) patients had recorded HbA1c levels | < 6.8% (n = 158, 50%) | · Cancer specific survival | |||||
| *HbA1c 6.8% used as cut-off point as it was the median value | · Overall survival | ||||||
| Gustafsson et al. 2009 [18] | Sweden | Prospective | Elective colorectal resection (including cancer, inflammatory bowel disease, benign pathology) | n = 120 | > 6.0% (n = 31, 25.8%) | 1 day before surgery | · Postoperative glucose control |
| ≤ 6.0% (n = 89, 74.2%) | · Magnitude of inflammatory response | ||||||
| · Postoperative recovery | |||||||
| · 30-day overall morbidity | |||||||
| Goh et al. 2017 [25] | Singapore | Retrospective | Colorectal surgery | n = 149 | ≥ 8% (n = 31, 23.8%) | Within 3 months of the surgery | · Postoperative complications (CD grade 2 and above) |
| 130 (87.2%) patients had recorded HbA1c levels | < 8% (n = 99, 76.2%) | ||||||
| Goodenough et al. 2015 [24] | USA | Prospective | *Abdominal surgery | n = 1017 | ≥ 6.5% (n = 183, 41.8%) | Within 3 months of the surgery | · Primary: Major complication CD grade 3–5 within 30 days |
| 438 (43.1%) patients had recorded HbA1c levels | < 6.5% (n = 255, 52.8%) | · Secondary: Any complication, including CD grade 1–2 | |||||
| Kamarajah et al. 2018 [26] | UK | Prospective | Gastrointestinal and hepatobiliary surgery | n = 381 | ≥ 6.5% (n = 49, 27.1%) | Within 3 months of the surgery | · Primary: 30-day complications defined by CD |
| 181 (47.5%) patients had recorded HbA1c levels | < 6.5% (n = 132, 72.9%) | · Secondary: Major complications, 30-day readmission rates, postoperative care setting | |||||
| Huang et al. 2017 [23] | China | Retrospective | Surgical resection for gastrointestinal cancer | n = 209 | ≥ 7% (n = 67, 56.8%) | Not stated | · 30-day and 180-day mortality rates |
| 118 (56.4%) patients had recorded HbA1c levels | < 7% (n = 51, 43.2%) | · Postoperative complications | |||||
| · Length of hospital stay | |||||||
| Jones et al. 2017 [33] | USA | Retrospective | Gastrointestinal surgery | n = 21541 | > 6.5% (n = 8822, 41.0%) | Within 3 months of the surgery | · Any post-operative complication |
| 5.7–6. 5% (n = 8118, 37.7%) | · Infectious complications (wound infection, pneumonia, urinary tract infection, sepsis) | ||||||
| < 5.7% (n = 4601, 21.4%) | · Post-discharge outcomes (readmission within 14 d, readmission within 30 d) | ||||||
| Villamiel et al. 2019 [17] | Philippines | Retrospective | Elective colorectal surgery | n = 157 | > 7% (n = 15, 34.1%) | Not stated | · Primary: Length of hospital stay |
| 44 (28%) patients had recorded HbA1c levels | ≤ 7% (n = 29, 65.9%) | · Secondary: Discharge within 30 postoperative days, postoperative complications, reoperation, pneumonia, wound infection | |||||
| Okamura et al. 2017 [19] | Japan | Retrospective | Esophagectomy for esophageal cancer | n = 300 | ≥ 6.5% (n = 27, 9%) | Within 3 months of the surgery | · Anastomotic leak |
| 6.0–6.4% (n = 50, 16.7%) | |||||||
| < 6.0% (n = 223, 74.3%) | |||||||
| Oh et al. 2018 [35] | South Korea | Retrospective | Elective major laparoscopic abdominal surgery | n = 1885 | ≥ 6.0% (n = 628, 33.3%) | Within 1 month of the surgery | · Acute kidney injury (post-operative day 0–3, stage 1–3) |
| < 6.0% (n = 1257, 66.7%) | |||||||
| Chen et al. 2018 [21] | China | Retrospective | Colorectal surgery | n = 126 | > 6.3%, (n = 67, 53.2%) | Not stated | · Anastomotic leak |
| ≤ 6.3% (n = 59, 46.8%) | |||||||
| Zhou et al. 2019 [34] | China | Retrospective | Colorectal and upper gastrointestinal surgery | n = 118 | 7–8% (n = 27, 22.9%) | Not stated | · Postoperative delirium |
| 6.5 ≤ 7% (n = 27, 22.9%) | |||||||
| 5.7 ≤ 6.5% (n = 34, 28.8%) | |||||||
| < 5.7% (n = 30, 25.4%) | |||||||
| Dai et al. 2017 [20] | China | Retrospective | Colorectal surgery | n = 201 | > 7% (n = 112, 55.7%) | Not stated | · Anastomotic leak |
| ≤ 7% (n = 89, 44.3%) | · Length of stay | ||||||
| · Duration of surgery | |||||||
| · Major intra-operative bleeding | |||||||
| · Infections | |||||||
| · Acute myocardial infarction | |||||||
| Zhang et al. 2008 [32] | China | Retrospective | Cholecystectomy | n = 86 | > 7.0 | Not stated | · Anastomotic leak |
| < 7.0 | · Infections | ||||||
| Number of patients per group not reported | |||||||
| Wang et al. 2010 [22] | China | Retrospective | Gastrointestinal tumor surgery | n = 82 | < 6.2 (n = 47, 79.7%) | Not stated | · Bloatedness |
| ≥ 6.2 (n = 35, 42.7%) | · Nausea and vomiting | ||||||
| · Anastomotic leak | |||||||
| · Time to flatus | |||||||
| · Length of hospital stay |
*
Included four gynecological procedures that constituted only 0.7% of the total number of surgeries.