Table 1.
Renal impairment and other characteristics of metformin initiators during the study period
| Northern Denmark N=22 728 |
UK N=101 992 |
|
|---|---|---|
| eGFR (most recent within a year before cohort entry)—n (%) | ||
| ≥60 mL/min/1.73 m2 | 20 677 (90.98) | 76 304 (74.81) |
| 45–59 mL/min/1.73 m2 | 1576 (6.93) | 20 648 (20.24) |
| 30–44 mL/min/1.73 m2 | 410 (1.80) | 4620 (4.53) |
| 15–29 mL/min/1.73 m2 | 61 (0.27) | 408 (0.40) |
| <15 mL/min/1.73 m2 | 4 (0.02) | 12 (0.01) |
| Metformin daily dose (mg) at cohort entry, mean (SD)* | 1433.53 (2410.20) | 1104.63 (426.64) |
| Metformin daily dose during follow-up (mg), mean (SD)* | 1387.37 (539.86) | 1265.86 (634.70) |
| Demographics at cohort entry | ||
| Age (years)—median (IQR) | 61 (51–69) | 63 (54–72) |
| Age (years)—n (%) | ||
| 30–39 | 1639 (7.21) | 4542 (4.45) |
| 40–49 | 3186 (14.02) | 12 566 (12.32) |
| 50–59 | 5572 (24.52) | 23 228 (22.77) |
| 60–69 | 6895 (30.34) | 29 098 (28.53) |
| 70–79 | 3971 (17.47) | 23 507 (23.05) |
| ≥80 | 1465 (6.45) | 9051 (8.87) |
| Female gender—n (%) | 10 269 (45.18) | 45 361 (44.48) |
| Male gender—n (%) | 12 459 (54.82) | 56 631 (55.52) |
| Duration of type 2 diabetes at cohort entry†—n (%) | ||
| First prescription at cohort entry | 21 799 (95.91) | 18 766 (18.40) |
| <1 year | 55 (0.24) | 32 868 (32.23) |
| 1–3 years | 220 (0.97) | 19 211 (18.84) |
| ≥3 years | 654 (2.88) | 31 147 (30.54) |
| HbA1c at cohort entry, %, mean (SD) (a) | 8.09 (1.91) | 8.67 (1.80) |
| History of potential contraindications for metformin within 5 years before cohort entry—n (%) | ||
| Diabetic ketoacidosis | 10 (0.04) | 69 (0.07) |
| Liver disease | 215 (0.95) | 1034 (1.01) |
| Alcohol-related diseases | 128 (0.56) | 1070 (1.05) |
| Co-medication within 90 days before cohort entry—n (%) | ||
| Other antidiabetic medications | 738 (3.25) | 20 141 (19.75) |
| NSAIDs | 3802 (16.73) | 11 965 (11.73) |
| Antihypertensives | 11 878 (52.26) | 64 112 (62.86) |
| Aspirin | 982 (4.32) | 28 954 (28.39) |
| Charlson Comorbidity Index Score at cohort entry—n (%) (a) | ||
| 0 | 16 196 (71.26) | 57 993 (56.86) |
| 1 | 3754 (16.52) | 24 592 (24.11) |
| 2 | 1781 (7.84) | 11 870 (11.64) |
| 3 | 585 (2.57) | 4704 (4.61) |
| ≥4 | 412 (1.81) | 2833 (2.78) |
| Lifestyle factors at cohort entry (where available) | ||
| Obesity‡ | NA | 54 100 (53.04) |
| Smoking | ||
| Current | NA | 17 505 (17.16) |
| Former | NA | 41 660 (40.85) |
| Never | NA | 40 957 (40.16) |
| Missing | NA | 1870 (1.83) |
*Based on non-missing values.
†In the UK, duration was defined as time since first antidiabetic prescription or first diagnosis of type 2 diabetes, whichever was earlier.
‡Defined as a body mass index ≥30 kg/m2.
eGFR, estimated glomerular filtration rate; HbA1c, glycated haemoglobin; NA, not available/applicable; NSAID, non-steroidal anti-inflammatory drug.