Baseline characteristics of people with type 1 diabetes and controls with no prior amputation by categories of HbA1c at first inclusion in the National Diabetes Register from 1998 to 2013
Controls n=182 617 | All type 1 diabetes n=36 577 | P value | |
Women* | 82 738 (45.3%) | 16 567 (45.3%) | 0.97 |
Age (years)* | 35.2 (14.6) n=182 617 | 35.2 (14.6) n=36 577 | 0.79 |
Age category | |||
18–34 | 102 427 (56.1%) | 20 495 (56.0%) | |
35–49 | 45 377 (24.8%) | 9083 (24.8%) | |
50–64 | 27 588 (15.1%) | 5533 (15.1%) | |
65+ | 7225 (4.0%) | 1466 (4.0%) | 0.72 |
Born in Sweden | 158 353 (86.7%) | 34 028 (93.0%) | <0.0001 |
Education category | |||
Low | 38 640 (21.5%) | 8091 (22.4%) | |
Mid | 92 477 (51.6%) | 19 378 (53.7%) | |
High | 48 234 (26.9%) | 8629 (23.9%) | <0.0001 |
Variables in the National Diabetes Register only | |||
HbA1c (mmol/mol, IFCC) | 66.1 (14.7) n=36 340 | ||
HbA1c (%, NGSP) | 8.20 (1.35) n=36 340 | ||
Diabetes duration (years) | 19.9 (14.7) n=36 577 | ||
Insulin method | |||
Injection | 27 972 (80.3%) | ||
Pump | 6841 (19.7%) | ||
BMI (kg/m2) | 25.9 (4.6) n=35 343 | ||
LDL (mmol/L) | 2.63 (0.82) n=33 009 | ||
Systolic BP (mm Hg) | 126.1 (15.7) n=36 121 | ||
Diastolic BP (mm Hg) | 72.6 (9.3) n=36 121 | ||
Smoking | 4435 (12.3%) | ||
Blood pressure-lowering medication | 14 171 (39.3%) | ||
Lipid-lowering medication | 12 978 (35.9%) | ||
eGFR | 93.5 (31.6) n=34 328 | ||
Albuminuria | |||
Normoalbuminuria | 26 797 (80.0%) | ||
Microalbuminuria | 3796 (11.3%) | ||
Macroalbuminuria | 217 (6.3%) | ||
CKD stage 5 | 794 (2.4%) | ||
Registrations in the inpatient register prior to baseline | |||
Acute myocardial infarction (I21) | 835 (0.5%) | 808 (2.2%) | <0.0001 |
Atrial fibrillation (I48) | 811 (0.4%) | 215 (0.6%) | 0.0004 |
Coronary heart disease (I20–I25) | 1667 (0.9%) | 1605 (4.4%) | <0.0001 |
Heart failure (I50) | 438 (0.2%) | 491 (1.3%) | <0.0001 |
Valve disease (I05–I09, I34–I36) | 359 (0.2%) | 134 (0.4%) | <0.0001 |
Stroke (I61–I64) | 726 (0.4%) | 548 (1.5%) | <0.0001 |
Cancer (C00–C97) | 2093 (1.1%) | 515 (1.4%) | <0.0001 |
Foot ulcer (circulatory complications) (E10.5, E11.5, E12.5, E13.5, E14.5) | 17 (0.0%) | 1349 (3.7%) | <0.0001 |
For categorical variables, n (%) is presented. For continuous variables, mean (SD) is presented.
*Variables used in the matching process.
BMI, body mass index; BP, blood pressure; CKD, chronic kidney disease; eGFR, estimated glomerular filtration rate; HbA1c, hemoglobin A1c; IFCC, International Federation of Clinical Chemistry; LDL, low-density lipoprotein; NGSP, National Glycohemoglobin Standardization Program.