Research Article
Low, rather than High, Body Mass Index Is a Risk Factor for Acute Kidney Injury in Multiethnic Asian Patients: A Retrospective Observational Study
Table 3
Baseline characteristics in relation to acute kidney injury categories according to KDIGO classification.
| | Total | No AKI | AKI |
| Number of patients | 12555 | 10949 | 1606 | Demographics | | | | Age, year | | | | Gender, men (%) | 6755 (53.8) | 5932 (54.2) | 8273 (51.2) | BMI, kg/m2 | | | | BMI, kg/m2 by categories (%) | | | | <18.5 | 1727 (13.8) | 1452 (13.3) | 275 (17.1) | 18.5–23 | 4339 (34.6) | 3775 (34.5) | 564 (35.1) | 23–27.5 | 3902 (31.1) | 3414 (31.2) | 488 (30.4) | >27.5 | 2587 (20.6) | 2308 (21.1) | 279 (17.4) | Ethnicity () | | | | Chinese | 7776 (61.9) | 6755 (61.7) | 1021 (63.4) | Malay | 2360 (18.8) | 2033 (18.6) | 327 (20.4) | Indian | 1485 (11.8) | 1334 (12.2) | 151 (9.4) | Others | 934 (7.4) | 827 (7.6) | 107 (6.7) | Specialty () | | | | Medicine | 6353 (50.6) | 5524 (50.4) | 829 (51.6) | Surgery | 1679 (13.4) | 1478 (13.5) | 201 (12.5) | Geriatrics | 1591 (12.7) | 1302 (11.9) | 289 (18.0) | Cardiology | 1479 (11.8) | 1301 (11.9) | 178 (11.0) | Orthopedic surgery | 1147 (9.1) | 1084 (9.9) | 63 (3.9) | Urology | 248 (2.0) | 205 (1.9) | 43 (2.7) | Otolaryngology | 41 (0.3) | 39 (0.4) | 2 (0.1) | Ophthalmology | 17 (0.1) | 16 (0.1) | 1 (0.1) | Background diagnosis () | | | | Hypertension | 4895 (39.0) | 4045 (36.9) | 850 (52.9) | Dyslipidemia | 3896 (31.0) | 3255 (29.7) | 641 (39.9) | Diabetes mellitus | 3289 (26.2) | 2644 (24.1) | 645 (40.2) | Cardiovascular disease | 2515 (20) | 2004 (18.3) | 511 (31.8) | Orthopedic related disease | 1402 (11.2) | 1146 (10.5) | 256 (15.9) | Cerebrovascular disease | 1314 (10.5) | 1053 (9.6) | 261 (16.3) | Neurological disease | 1219 (9.7) | 1003 (9.2) | 216 (13.4) | Respiratory disease | 1030 (8.2) | 899 (8.2) | 131 (8.2) | Hematological disease | 955 (7.6) | 739 (6.7) | 216 (13.4) | Gastrointestinal disease | 936 (7.5) | 787 (7.2) | 149 (9.3) | Chronic kidney disease | 857 (6.8) | 615 (5.6) | 242 (15.1) | Psychiatric illness | 760 (6.1) | 626 (5.7) | 134 (8.3) | Urological disease | 595 (4.7) | 465 (4.2) | 130 (8.1) | Underlying malignancy | 584 (4.7) | 459 (4.2) | 125 (7.8) | Hepatobiliary disease | 463 (3.7) | 350 (3.2) | 113 (7.0) | Procedures () | | | | Endoscopy | 2355 (18.8) | 1941 (17.7) | 414 (25.8) | Orthopedic surgery | 1222 (9.7) | 1072 (9.8) | 150 (9.3) | Cardiology related procedures (non-open-heart surgery) | 584 (4.7) | 538 (4.9) | 46 (2.9) | Excision of skin lesions | 851 (6.8) | 734 (6.7) | 117 (7.3) | Open laparotomy | 579 (4.6) | 468 (4.3) | 111 (6.9) | Urology related surgery | 510 (4.1) | 406 (3.7) | 105 (6.5) | Laparoscopic surgery (intra-abdominal) | 265 (2.1) | 243 (2.2) | 22 (1.4) | Neurosurgery | 159 (1.3) | 131 (1.2) | 28 (1.7) | Otolaryngology related surgery | 149 (1.2) | 112 (1.0) | 37 (2.3) | Vascular surgery, open | 57 (0.5) | 49 (4) | 8 (0.5) | Laparoscopic assisted bariatric bypass surgery | 12 (0.18) | 11 (0.1) | 1 (0.1) | Hospitalisation characteristics | | | | ICU admission (%) | 1638 (13.0) | 1204 (11.0) | 434 (27.0) | Mortality within 90 days of admission (%) | 997 (7.9) | 572 (5.2) | 425 (26.5) | Length of stay (d, IQR) | 5 (3–9) | 4 (3–8) | 11 (5–21) | Creatinine measurements | | | | Time from baseline measurement to hospitalisation (d, IQR) | 71 (29.3–147) | 67 (26–144) | 79 (37.3–155.5) | Number of measurements within 365 days before hospitalisation (, IQR) | 4 (2–6) | 4 (2–6) | 5 (3–8) |
|
|
AKI: acute kidney injury; ICU: intensive care unit; BMI: body mass index; IQR: interquartile range.
|