Fig. 1Study protocol (left image) and photo of the Actigraph device (Actigraph Corp.) on a wrist (right image). T2DM, type 2 diabetes mellitus; OGTT, oral glucose tolerance test; HbA1c, glycosylated hemoglobin; DM, diabetes mellitus.
Fig. 2Sleep quality data acquired with the Actigraph (Actigraph Corp.) in the type 2 diabetes mellitus (T2DM), prediabetes, and normal glucose tolerance (NGT) groups; arrows indicate the sleep onset and wake up points (representative data of each group). EF, efficiency.
Table 1.Baseline characteristics of the study participants
Characteristic |
T2DM (n=30) |
Prediabetes (n=30) |
NGT (n=30) |
P value |
Age, yr |
47.3±10.68 |
52.5±11.03 |
42.9±12.45 |
0.007 |
Sex, male/female |
23/7 (76.7) |
8/22 (26.7) |
9/21 (30) |
<0.001 |
DM duration, yr |
2.23±2.32 |
- |
- |
|
BMI, kg/m2
|
25.74±4.49 |
26.23±3.13 |
24.90±3.28 |
0.372 |
HbA1c, % |
7.83±2.01 |
5.80±0.24 |
5.31±0.22 |
<0.001 |
LDL, mg/dL |
95.33±49.78 |
108.63±35.48 |
104.67±27.57 |
0.402 |
Triglyceride, mg/dL |
155.56±66.83 |
159.03±100.98 |
143.58±100.87 |
0.792 |
HDL, mg/dL |
43.56±11.82 |
53.53±15.69 |
51.13±15.97 |
0.026 |
Total cholesterol, mg/dL |
156.06±50.22 |
181.13±38.59 |
178.46±30.61 |
0.036 |
eGFR, mL/min/1.73 m2
|
122.87±21.00 |
118.57±36.68 |
121.08±34.07 |
0.867 |
Creatinine |
0.70±0.13 |
0.64±0.23 |
0.68±0.19 |
0.448 |
Hemoglobin, g/dL |
14.73±1.93 |
14.10±1.34 |
13.67±1.44 |
0.040 |
T3, ng/dL |
91.30±19.19 |
109.28±33.03 |
107.96±18.05 |
0.025 |
Free T4, ng/dL |
1.22±0.17 |
1.20±0.23 |
1.19±0.17 |
0.834 |
TSH, µIU/mL |
1.49±1.14 |
1.85±1.47 |
1.73±1.55 |
0.645 |
Table 2.Comparisons of objective sleep quality measurements from the Actigraph among the three groups
Variable |
T2DM |
Prediabetes |
NGT |
P value |
Total sleep time, min |
362.23±89.37 |
363.24±60.86 |
345.71±41.84 |
0.525 |
Sleep efficiency, % |
86.25±7.09 |
87.99±6.44 |
90.22±4.53 |
0.047 |
WASO, frequency |
56.72±35.29 |
49.05±26.84 |
37.34±19.90 |
0.031 |
Awake, frequency |
19.73±7.22 |
17.92±6.62 |
15.21±5.04 |
0.025 |
Average awake, frequency |
2.81±1.03 |
2.65±0.79 |
2.49±1.26 |
0.500 |
Table 3.Correlation analysis of sleep efficiency, wakening frequency and metabolic parameters
Variable |
Age |
BMI |
HbA1c |
LDL |
TG |
HDL |
TC |
eGFR |
Hb |
Efficiency |
–0.069 |
–0.209 |
–0.348 |
0.070 |
0.073 |
0.093 |
0.126 |
–0.098 |
–0.080 |
P value |
0.517 |
0.054 |
0.001 |
0.518 |
0.496 |
0.384 |
0.237 |
0.359 |
0.454 |
Awake |
0.155 |
0.038 |
0.215 |
–0.143 |
–0.016 |
–0.081 |
–0.155 |
–0.019 |
0.078 |
P value |
0.144 |
0.728 |
0.042 |
0.184 |
0.883 |
0.449 |
0.145 |
0.861 |
0.465 |
Table 4.Multiple regression analysis of HbA1c level and sleep efficiency after adjusting for age and BMI
Sleep efficiency |
B |
β |
t
|
P value |
VIF |
Constant |
106.871 |
|
18.292 |
<0.001 |
|
Age |
–0.046 |
–0.088 |
–0.856 |
0.394 |
1.020 |
BMI |
–0.334 |
–0.195 |
–1.906 |
0.060 |
1.025 |
HbA1c |
–1.279 |
–0.328 |
–3.234 |
0.002 |
1.007 |