No diabetes Diabetes, no insulin Diabetes, + insulin
  n=674 n=289 n=99
MMSE score, mean ± SD 25.5 ± 3.4 24.8 ± 3.6** 24.2 ± 4.0***
Verbal fluency, mean ± SD 28.6 ± 12.5 26.5 ± 12.3* 25.0 ± 11.8**
Digit span, mean ± SD 14.1 ± 3.8 13.5 ± 3.5* 12.7 ± 3.4***
WLL delayed recall, mean ± SD 3.7 ± 2.9 3.5 ± 2.8 3.4 ± 2.7
LM delayed recall, mean ± SD 19.0 ± 9.8 17.4 ± 9.8* 17.9 ± 9.4
Trailmaking A, mean ± SD 83.7 ± 57.4 89.1 ± 61.6 94.4 ± 62.5*
Trailmaking B, mean ± SD 205.3 ± 84.3 214.7 ± 84.5 232.4 ± 76.8***
Block design, mean ± SD 20.7 ± 9.1 19.7 ± 9.3 17.9 ± 8.3**
Subjects are divided into three subgroups: those who did not have diabetes, those who had diabetes without insulin treatment and those who had diabetes with insulin treatment. Mean ± SD with T-test is used to describe the distributions and comparisons of test scores in each cognitive domain between those who did not have diabetes and either diabetic subgroup. P values for the statistical significance are shown with *p<0.05; **p<0.01; ***p<0.001
WLL = Word learning list; LM = Logical memory
Table 4: Comparisons of cognitive function between non-diabetic and diabetic subgroups in the context of insulin treatment.