Table 1

Characteristics (median [quartile 1, quartile 3]) or n (%) of the people studied when starting insulin, according to their weight gain at 12 months, and β coefficients from linear models adjusted for the investigational site as a random factor

Weight gain at 12 months (kg)β coefficient*(95% CI)P
Item<2.0 n = 1,0872.0–4.9 n = 5815.0–9.9 n = 405≥10 n = 106
Age (years)62 (55, 69)61 (55, 68)60 (53, 69)58 (53, 67)−0.013(–0.032 to 0.007)0.204
Men536 (49%)282 (48%)202 (50%)57 (54%)0.123(–0.274 to 0.520)0.543
Women551 (51%)299 (52%)203 (50%)49 (46%)
Smoking0.153
 Never smoked637 (59%)345 (59%)232 (57%)48 (45%)Reference
 Stopped ≥1 year272 (25%)131 (23%)97 (24%)28 (26%)−0.302(–0.776 to 0.171)0.211
 Stopped <1 year30 (3%)16 (3%)18 (4%)8 (8%)0.735(–0.357 to 1.828)0.187
 Currently smokes148 (14%)89 (15%)58 (14%)22 (21%)0.277(–0.291 to 0.846)0.339
BMI (kg/m2)29.1 (25.9, 33.5)29.1 (25.9, 33.5)27.5 (24.0, 31.6)28.4 (23.7, 33.5)−0.124(–0.156 to –0.091)<0.001
Duration of diabetes (years)9 (5, 14)9 (5, 15)10 (5, 15)9 (5, 14)0.007(–0.018 to 0.033)0.579
A1C (%)9.0 (8.0, 10.2)9.2 (8.1, 10.4)9.9 (8.6, 11.4)10.1 (8.8, 11.7)1.346(1.034 to 1.659)<0.001
A1C (mmol/mol)75 (64, 88)77 (65, 90)85 (70, 101)87 (73, 104)0.123(0.095 to 0.152)<0.001
Diagnosed hypertension792 (73%)389 (67%)268 (66%)68 (64%)−0.755(–1.183 to –0.328)0.001
Microvascular disease825 (76%)453 (78%)307 (76%)87 (82%)−0.259(–0.748 to 0.231)0.300
Macrovascular disease370 (34%)207 (36%)141 (35%)44 (42%)−0.022(–0.437 to 0.392)0.916
Insulin regimen<0.001
 Basal insulin alone599 (56%)304 (53%)169 (42%)42 (40%)Reference
 Basal + mealtime132 (12%)92 (16%)74 (19%)25 (24%)1.376(0.776 to 1.974)<0.001
 Mealtime alone74 (7%)34 (6%)37 (25%)4 (4%)0.093(–0.745 to 0.933)0.827
 Premix243 (23%)121 (21%)101 (25%)29 (28%)0.774(0.253 to 1.295)0.004
 Other28 (3%)21 (4%)18 (4%)5 (5%)1.766(0.609 to 2.922)0.003
Other diabetes drugs0.004
 None325 (30%)198 (34%)172 (42%)44 (42%)Reference
 One428 (39%)190 (33%)149 (37%)40 (38%)−0.615(–1.084 to –0.147)0.010
 Two282 (26%)163 (28%)70 (17%)19 (18%)−0.909(–1.446 to –0.372)0.001
 Three or more52 (5%)30 (5%)14 (4%)3 (3%)−1.054(–2.042 to –0.066)0.037
Biguanides553 (51%)280 (48%)169 (42%)50 (47%)−0.513(–0.914 to – 0.111)0.012
Sulfonylureas385 (35%)213 (34%)89 (22%)26 (24%)−0.554(–0.990 to – 0.118)0.013
Daily insulin dose (IU/kg)0.18 (0.12, 0.31)0.20 (0.13, 0.33)0.27 (0.15, 0.42)0.31 (0.20, 0.47)4.814(3.673 to 5.955)<0.0001
  • *For categorical measures, β coefficients are given for yes vs. no, or against the reference group stated.

  • †Data were loge transformed for analysis, so the β coefficients are for loge of a unit difference.