Table 1—

Results of neurocognitive tests

Type 1 diabetic patients
Healthy subjects
P value
Control nightHypoglycemic nightControl nightHypoglycemic night
Word pairs
    Number of trials1.31 ± 0.121.50 ± 0.131.63 ± 0.131.63 ± 0.13NS
    Before sleep28.8 ± 1.129.3 ± 0.930.4 ± 1.031.1 ± 1.0NS
    After sleep30.6 ± 1.030.2 ± 1.332.4 ± 1.131.1 ± 1.3NS
    Δ+1.9 ± 1.0+0.9 ± 0.9+2.1 ± 0.5+0.1 ± 0.6*
Word subtest
    Before sleep (s)45 ± 345 ± 243 ± 444 ± 5NS
    After sleep (s)45 ± 246 ± 243 ± 344 ± 4NS
Color subtest
    Before sleep (s)59 ± 355 ± 260 ± 459 ± 4NS
    After sleep (s)57 ± 258 ± 355 ± 456 ± 4NS
Interference subtest
    Before sleep (s)92 ± 581 ± 580 ± 487 ± 8NS
    After sleep (s)91 ± 579 ± 479 ± 582 ± 6NS
ERPs
    P3 A (μV)13.0 ± 3.215.0 ± 2.714.0 ± 2.312.1 ± 2.2NS
    P3 L (ms)351 ± 10332 ± 8350 ± 11347 ± 8NS
    N1 A (μV)−4.9 ± 0.7−7.3 ± 2.6−5.35 ± 0.7−4.96 ± 1.4NS
    N1 L (ms)117 ± 4113 ± 3104 ± 2114 ± 5NS
    RT (ms)417 ± 31416 ± 37423 ± 31395 ± 29NS
  • Data are means ± SEM. P values are derived from ANOVA, including a group factor (type 1 diabetic vs. healthy control subjects) and the repeated-measures factors hypoglycemic (hypoglycemic vs. euglycemic control night) and time (performance before sleep vs. after sleep). Data given for N1 amplitude (A) and latency (L) were recorded at Cz and those for P3 amplitude and latency at Pz.

  • * P < 0.05 for the main effect of time;

  • P < 0.01 for hypoglycemic × time interaction. Δ, difference between the numbers of recalled word pairs at retrieval testing in the morning and at learning before sleep; RT, reaction time.