Baseline characteristics of patients with ICH according to BMI categories
| Variable | Underweight (n=3081) | Normal weight (n=31 525) | Overweight (n=23 818) | Obese (n=24 365) | P value |
| Age (years), mean±SD | 69.4±14.1 | 64.5±13.0 | 62.3±12.2 | 60.6±12.6 | <0.0001 |
| Male, n (%) | 1506 (48.9) | 19 067 (60.5) | 15 763 (66.2) | 15 325 (62.9) | <0.0001 |
| Level of education, n (%) | |||||
| Elementary or below | 1322 (42.9) | 11 017 (34.9) | 7474 (31.4) | 7199 (29.5) | <0.0001 |
| Middle school | 426 (13.8) | 5572 (17.7) | 4983 (20.9) | 5345 (21.9) | <0.0001 |
| High school or above | 266 (8.6) | 3329 (10.6) | 2803 (11.8) | 3338 (13.7) | <0.0001 |
| Health insurance status, n (%) | <0.0001 | ||||
| UEMRS | 540 (17.5) | 5756 (18.3) | 4803 (20.2) | 5424 (22.3) | |
| URMIS | 517 (16.8) | 5150 (16.3) | 3657 (15.4) | 3746 (15.4) | |
| NRCMS | 1687 (54.8) | 16 989 (53.9) | 12 708 (53.4) | 12 480 (51.2) | |
| Self-pay | 208 (6.8) | 2382 (7.6) | 1733 (7.3) | 1865 (7.7) | |
| Others | 129 (4.2) | 1248 (4.0) | 917 (3.9) | 850 (3.5) | |
| Admission time period, n (%) | <0.0001 | ||||
| 2015 | 86 (2.8) | 1111 (3.5) | 854 (3.6) | 912 (3.7) | |
| 2016 | 864 (28.0) | 7844 (24.9) | 5633 (23.7) | 6108 (25.1) | |
| 2017 | 759 (24.6) | 8488 (26.9) | 6447 (27.1) | 6363 (26.1) | |
| 2018 | 929 (30.2) | 9256 (29.4) | 7085 (29.7) | 7134 (29.3) | |
| 2019 | 443 (14.4) | 4826 (15.3) | 3799 (16.0) | 3848 (15.8) | |
| Pre-stroke mRS, n (%) | <0.0001 | ||||
| 0–2 | 2076 (67.4) | 22 110 (70.1) | 17 192 (72.2) | 17 728 (72.8) | |
| 3–5 | 784 (25.4) | 7707 (24.4) | 5579 (23.4) | 5341 (21.9) | |
| NIHSS, mean±SD | 9.2±9.3 | 8.5±8.7 | 8.2±8.3 | 8.4±8.8 | 0.0591 |
| GCS, mean±SD | 11.4±4.0 | 11.6±4.0 | 11.4±4.1 | 11.3±4.2 | <0.0001 |
| Behavioural history, n (%) | |||||
| Current smoking | 492 (16.0) | 5775 (18.3) | 4944 (20.8) | 5067 (20.8) | <0.0001 |
| Drinking | 556 (18.0) | 7110 (22.6) | 5999 (25.2) | 6574 (27.0) | <0.0001 |
| Medical history, n (%) | |||||
| Hypertension | 2000 (64.9) | 21 573 (68.4) | 17 076 (71.7) | 18 477 (75.8) | <0.0001 |
| Diabetes mellitus | 202 (6.6) | 2576 (8.2) | 2242 (9.4) | 2864 (11.8) | <0.0001 |
| Dyslipidaemia | 116 (3.8) | 1187 (3.8) | 933 (3.9) | 1293 (5.3) | <0.0001 |
| Atrial fibrillation | 67 (2.2) | 526 (1.7) | 318 (1.3) | 357 (1.5) | <0.0001 |
| TIA | 29 (0.9) | 191 (0.6) | 110 (0.5) | 172 (0.7) | <0.0001 |
| Ischaemic stroke | 423 (13.7) | 4005 (12.7) | 3046 (12.8) | 3313 (13.6) | <0.0001 |
| SAH | 17 (0.6) | 170 (0.5) | 130 (0.5) | 138 (0.6) | 0.9786 |
| ICH | 667 (21.6) | 5847 (18.5) | 4122 (17.3) | 4185 (17.2) | <0.0001 |
| Heart failure | 39 (1.3) | 166 (0.5) | 86 (0.4) | 101 (0.4) | <0.0001 |
| Myocardial infarction | 20 (0.6) | 271 (0.9) | 218 (0.9) | 237 (1.0) | 0.0003 |
| Peripheral vascular disease | 41 (1.3) | 301 (1.0) | 210 (0.9) | 248 (1.0) | <0.0001 |
| Medication history, n (%) | |||||
| Antiplatelet | 187 (6.1) | 2006 (6.4) | 1625 (6.8) | 1904 (7.8) | <0.0001 |
| Anticoagulation | 59 (1.9) | 593 (1.9) | 437 (1.8) | 485 (2.0) | <0.0001 |
| Antihypertensive | 1254 (40.7) | 13 989 (44.4) | 11 452 (48.1) | 12 459 (51.1) | <0.0001 |
| Antidiabetic | 139 (4.5) | 1919 (6.1) | 1627 (6.8) | 2085 (8.6) | <0.0001 |
| Cholesterol-reduce | 97 (3.1) | 933 (3.0) | 684 (2.9) | 745 (3.1) | 0.2620 |
| Lab tests, mean±SD | |||||
| LDL (mmol/L) | 2.8±1.7 | 2.8±1.5 | 2.8±1.5 | 2.9±1.7 | <0.0001 |
| Glycated haemoglobin (%) | 5.9±1.8 | 5.9±1.7 | 5.9±1.7 | 6.0±1.8 | <0.0001 |
| FBG (mmol/L) | 6.4±2.8 | 6.4±2.7 | 6.5±2.8 | 6.8±3.0 | <0.0001 |
| Hcy (μmol/L) | 13.7±8.4 | 13.9±8.0 | 14.2±8.0 | 14.3±8.1 | <0.0001 |
| Creatinine (μmol/L) | 141.7±1327.7 | 140.5±1270.3 | 141.9±1412.2 | 150.8±1399.6 | 0.828 |
| BUN (mmol/L) | 6.0±3.1 | 5.8±2.8 | 5.7±2.7 | 5.7±2.7 | <0.0001 |
| UA (μmol/L) | 268.8±140.1 | 284.1±133.2 | 289.0±132.4 | 295.9±142.8 | <0.0001 |
| Platelets (×109/L) | 199.6±74.5 | 201.1±71.1 | 202.6±69.1 | 206.2±69.6 | <0.0001 |
| SBP (mm Hg), mean±SD | 162.2±29.3 | 163.1±28.0 | 164.8±27.6 | 166.7±28.5 | <0.0001 |
| DBP (mm Hg), mean±SD | 91.2±16.8 | 93.9±16.6 | 95.6±16.5 | 97.2±17.2 | <0.0001 |
| In-hospital treatment, n (%) | |||||
| Haematoma evacuation | 202 (6.6) | 2798 (8.9) | 2640 (11.1) | 2915 (12.0) | <0.0001 |
| LOS (days), mean±SD | 15.9±11.9 | 16.4±11.5 | 16.6±11.7 | 16.8±11.8 | <0.0001 |
| Hospital expenditure (RMB), mean±SD | 17 444.2±16 541.5 | 17 910.8±16 480.4 | 18 461.0±17 184.0 | 18 777.8±17 486.9 | <0.0001 |
BMI, body mass index; BUN, blood urea nitrogen; DBP, diastolic blood pressure; FBG, fasting blood glucose; GCS, Glasgow Coma Scale; Hcy, homocysteine; ICH, intracerebral haemorrhage; LDL, low-density lipoprotein; LOS, length of stay; ; mRS, modified Rankin Scale; NIHSS, National Institutes of Health Stroke Scale; NRCMS, New Rural Cooperative Medical Scheme; RMB, renminbi; SAH, subarachnoid haemorrhage; SBP, systolic blood pressure; TIA, transient ischaemic attack; UA, uric acid; UEMRS, Urban Employee Medical Insurance; URMIS, Urban Residents Medical Insurance.