Table 1.
Baseline characteristics of the study sample in the different categories of socioeconomic status.
| Variable | Obs, n = 402 | Quartile 1 income, n = 101 | Quartile 2 income, n = 102 | Quartile 3 income, n = 99 | Quartile 4 income, n = 100 | p value |
|---|---|---|---|---|---|---|
| Age | 67.3 ± 10.4 | 67.8 ± 11.7 | 66.5 ± 10.8 | 67.5 ± 8.4 | 67.4 ± 10.5 | 0.848 |
| Sex, women | 149 (37.1%) | 42 (41.6) | 40 (39.2) | 37 (37.4) | 30 (30.0) | 0.357 |
| Duration of diabetes (years) | 17.8 ± 4.8 | 18.0 ± 3.8 | 17.3 ± 5.6 | 18.2 ± 6.0 | 17.7 ± 3.5 | 0.608 |
| Net income/person/year (€) | 15,379 ± 5260 | 10,484 ± 1186 | 12,635 ± 521 | 15,488 ± 1205 | 23,015 ± 4223 | < 0.001 |
| BMI (kg/m2) | 28.7 ± 4.7 | 29.8 ± 4.9 | 27.9 ± 4.0 | 28.5 ± 4.4 | 28.5 ± 5.1 | 0.029 |
| Smokers | 61 (15.3%) | 18 (18.2) | 19 (18.6) | 13 (13.3) | 11 (11.0) | 0.355 |
| HbA1c (%) | 8.5 ± 1.5 | 8.9 ± 1.8 | 8.4 ± 1.5 | 8.5 ± 1.3 | 8.2 ± 1.3 | 0.009 |
| Insulin dose (IU/kg) | 0.62 ± 0.31 | 0.58 ± 0.29 | 0.66 ± 0.30 | 0.62 ± 0.31 | 0.60 ± 0.36 | 0.359 |
| Other antidiabetic agents | 2 (1–2) | 1 (0–2) | 2 (1–2) | 2 (1–2) | 2 (1–2) | 0.315 |
| Retinopathy | 146 (36.3%) | 46 (45.5) | 36 (35.3) | 30 (30.3) | 34 (34.0) | 0.136 |
| Nephropathy | 220 (54.7) | 54 (53.5) | 51 (50.0) | 53 (53.5) | 62 (62.0) | 0.365 |
| Ischemic heart disease | 99 (24.6) | 21 (20.8) | 19 (18.6) | 33 (33.3) | 26 (26.0) | 0.074 |
| Stroke | 36 (9.0) | 8 (7.9) | 10 (9.8) | 7 (7.1) | 11 (11.0) | 0.761 |
Note: Continuous variables are expressed as mean ± standard deviation and categorical variables as n (%). Differences between quartiles were analyzed with ANOVA.
Abbreviations: BMI, body mass index; HbA1c, glycated hemoglobin.