Patient characteristics according to severity of hypoglycaemia during follow-up
| Total group (N=1667) | No hypoglycaemia (N=804 (48%)) | Only mild hypoglycaemia (N=744 (45%)) | Severe hypoglycaemia (N=119 (7%)) | |
|---|---|---|---|---|
| Baseline characteristics | ||||
| Age, years | 67.2±11.7 | 68.7±12.2 | 65.6±11.0* | 67.7±12.3 |
| Women | 784 (47%) | 364 (45%) | 357 (48%) | 63 (53%) |
| Diabetes duration, years | 11.5 (7.9–15.9) | 11.2 (7.3–14.9) | 12.0 (8.2–16.5)* | 12.1 (8.2–18.4)* |
| Duration of insulin use, years | 4.6 (2.1–7.6) | 4.3 (1.8–6.5) | 4.9 (2.7–8.7)* | 5.5 (3.8–10.1)* |
| Type of insulin | ||||
| Only intermediate/long acting | 714 (43%) | 419 (52%) | 266 (36%)* | 29 (24%)* |
| Combination of fast and intermediate/long acting | 885 (53%) | 341 (42%) | 459 (62%)* | 85 (71%)* |
| Use of oral antidiabetic medication (next to insulin) | ||||
| No oral antidiabetic medication | 416 (25%) | 177 (22%) | 194 (26%) | 45 (38%)* |
| Only metformin | 642 (39%) | 285 (35%) | 305 (41%)* | 52 (44%) |
| Only SU | 95 (6%) | 65 (8%) | 29 (4%)* | 1 (1%)* |
| Metformin and SU | 449 (27%) | 238 (30%) | 190 (26%) | 21 (18%)* |
| Other† | 65 (4%) | 39 (5%) | 26 (3%) | 0 |
| HbA1c, % (mmol/mol) | 7.6±1.2 (60±13) | 7.6±1.2 (60±12) | 7.5±1.1 (58±12) | 7.8±1.3 (62±14) |
| BMI, kg/m‡ | 31.3±5.9 | 31.6±5.8 | 31.2±5.9 | 30.5±6.2 |
| Smoking | 342 (21%) | 160 (20%) | 156 (21%) | 26 (22%) |
| UAC ratio, mg/mmol | 2.0 (0.8–6.4) | 2.1 (0.9–6.9) | 1.9 (0.8–5.9) | 2.3 (0.8–4.8) |
| eGFR | 80.3±24.9 | 79.6±25.9 | 81.2±23.3 | 79.3±27.0 |
| Hypertension‡ | 1411 (85%) | 685 (85%) | 626 (84%) | 100 (84%) |
| SBP, mm Hg | 144.3±22.1 | 144.7±22.6 | 143.9±21.6 | 143.9±21.7 |
| DBP, mm Hg | 76.4±9.3 | 76.7±10.0 | 76.2±8.5 | 75.7±9.1 |
| Use of antihypertensive medication | 1222 (73%) | 590 (73%) | 548 (74%) | 84 (71%) |
| Cardiovascular history§ | 339 (20%) | 153 (19%) | 156 (21%) | 30 (25%) |
| CVA | 65 (4%) | 34 (4%) | 25 (3%) | 6 (5%) |
| MI | 218 (13%) | 101 (13%) | 98 (13%) | 19 (16%) |
| TIA | 99 (6%) | 39 (5%) | 51 (7%) | 9 (8%) |
| Retinopathy | ||||
| No | 1164 (70%) | 563 (70%) | 524 (70%) | 77 (65%)* |
| Mild | 78 (5%) | 28 (4%) | 37 (5%) | 13 (11%) |
| Severe | 13 (1%) | 7 (1%) | 5 (1%) | 1 (1%) |
| Educational level | ||||
| Low | 786 (47%) | 385 (48%) | 344 (46%) | 57 (48%) |
| Middle | 541 (33%) | 234 (29%) | 267 (36%) | 40 (34%) |
| High | 204 (12%) | 97 (12%) | 99 (13%) | 8 (7%) |
| Follow-up characteristics | ||||
| Number of mild hypoglycaemic events during follow-up (in total group) | 0 (0–12) | NA | 24 (4–64) | 0 (0–24) |
| Number of patients who reported mild hypoglycaemia during follow-up | 803 (48%) | NA | 744 (100%) | 59 (50%) |
| Number of mild hypoglycaemic events during follow-up (in patients reporting hypoglycaemia) | 24 (5–65) | NA | 24 (4–64) | 24 (12–101) |
| Number of severe hypoglycaemic events during follow-up | 0 (0–0) | NA | NA | 2 (2–13) |
| Follow-up duration, years¶ | 1.9 (1.1–2.4) | 1.8 (1.1–2.3) | 1.9 (1.2–2.5)* | 2.1 (1.5–2.6)* |
| Mortality | 98 (5.9%) | 67 (8.3%) | 24 (3.2%)* | 7 (5.9%) |
Data are presented as numbers (%), mean±SD or median (IQR).
*Significantly different (p<0.05) compared with the patients who reported no hypoglycaemia during follow-up; differences in characteristics between the groups were tested using χ2 for dichotomous and nominal categorical variables, using χ2 including tests for trends for ordinal categorical variables, using independent-samples Student's t-tests for continuous variables, and Mann-Whitney's U tests for continuous variables that were not normally distributed.
†Other oral antidiabetic medication=other than metformin and SU, whether or not combined with metformin and/or SU.
‡Hypertension is defined as either an SBP≥140 mm Hg, a DBP≥90 mm Hg or use of antihypertensive medication.
§Patients can be in more than one subcategory if they have experienced more than one type of cardiovascular event.
¶Follow-up duration is defined as either the time between baseline and 1/1/2013, or, if someone died before 1/1/2013, as the time between baseline and mortality.
BMI, body mass index; CVA, cerebral vascular accident; DBP, diastolic blood pressure; eGFR, estimated glomerular filtration rate; HbA1c, glycated haemoglobin; MI, myocardial infarction; NA, not applicable; SBP, systolic blood pressure; SU, sulfonylurea; TIA, transient ischaemic attack; UAC, urinary albumin–creatinine.