NOTES
-
CONFLICTS OF INTEREST
No potential conflict of interest relevant to this article was reported.
-
AUTHOR CONTRIBUTIONS
Conception or design: H.S.C., S.W.L., J.T.K., H.K.L.
Acquisition, analysis, or interpretation of data: H.S.C., S.W.L., J.T.K., H.K.L.
Drafting the work or revising: H.S.C., J.T.K., H.K.L.
Final approval of the manuscript: H.S.C., S.W.L., J.T.K., H.K.L.
Fig. 1Kaplan-Meier plot for the cumulative proportions of diabetes mellitus (DM) according to quartiles of (A) forced vital capacity (FVC) (% predicted) and (B) forced expiratory volume in 1 second (FEV1) (% predicted).
Fig. 2(A) Forced vital capacity (FVC) (% predicted) and (B) forced expiratory volume in 1 second (FEV1) (% predicted) according to diabetes mellitus (DM) development and time. Markers represents mean values at each time, and vertical lines represent 95% confidential intervals. Solid line with circle marker represents non-DM progressors, and dashed line with hollow circle marker represents DM progressors.
Table 1.Baseline characteristics according to the quartiles of FVC (% predicted) and FEV1 (% predicted)
Characteristic |
Quartiles of FVC (% predicted)
|
Quartiles of FEV1 (% predicted)
|
1st |
2nd |
3rd |
4th |
P value/P for trend |
1st |
2nd |
3rd |
4th |
P valuea/P for trendb
|
No. of cases |
1,105 |
1,088 |
1,125 |
1,202 |
|
1,074 |
1,152 |
1,112 |
1,180 |
|
Values, % predicted |
86.33±9.15 |
101.68±2.82 |
111.24±2.85 |
126.61±9.39 |
|
88.63±9.99 |
107.37±3.65 |
119.36±3.39 |
137.61±10.46 |
|
Age, yr |
55.3±8.8 |
54.5±9.0 |
55.1±8.7 |
56.3±8.6 |
<0.001/0.002 |
55.3±8.8 |
54.3±8.8 |
54.6±8.7 |
56.9±8.5 |
<0.001/<0.001 |
Male sex, % |
53.3 |
44.5 |
45.2 |
33.7 |
<0.001/<0.001 |
60.6 |
51.8 |
37.9 |
26.8 |
<0.001/<0.001 |
BMI, kg/m2
|
24.68±3.50 |
24.70±3.36 |
24.48±3.10 |
24.28±3.03 |
0.005/<0.001 |
24.21±3.35 |
24.70±3.34 |
24.65±3.13 |
24.53±3.17 |
0.002/0.035 |
WC, cm |
85.2±9.3 |
84.8±8.8 |
84.5±8.1 |
84.0±8.4 |
0.006/<0.001 |
84.4±8.9 |
85.1±8.6 |
84.8±8.2 |
84.3±8.8 |
0.114/0.564 |
Hip circumference, cm |
91.7±6.3 |
91.8±6.2 |
91.5±5.8 |
91.1±6.0 |
0.030/0.004 |
91.3±6.1 |
92.0±6.1 |
91.7±5.9 |
91.1±6.2 |
0.002/0.189 |
WH ratio, % |
0.93±0.06 |
0.92±0.07 |
0.92±0.06 |
0.92±0.06 |
0.044/0.005 |
0.92±0.06 |
0.92±0.07 |
0.92±0.06 |
0.92±0.06 |
0.758/0.815 |
Met SD, % |
46.0 |
44.9 |
41.0 |
40.5 |
0.015/0.002 |
39.8 |
43.5 |
44.5 |
44.2 |
0.100/0.038 |
DM at baseline, % |
19.2 |
15.3 |
13.7 |
10.3 |
<0.001/<0.001 |
17.0 |
15.0 |
14.5 |
11.9 |
0.007/0.001 |
SBP, mm Hg |
130.3±18.7 |
130.0±18.9 |
128.4±18.9 |
128.3±19.3 |
0.018/0.001 |
129.7±18.9 |
129.4±18.9 |
129.3±18.8 |
128.4±19.3 |
0.394/0.091 |
DBP, mm Hg |
84.7±10.9 |
83.8±11.3 |
83.4±11.4 |
82.7±11.5 |
0.001/<0.001 |
84.5±10.9 |
83.7±11.3 |
83.6±11.6 |
82.8±11.4 |
0.006/<0.001 |
Smoking, % |
|
|
|
|
<0.001/<0.001 |
|
|
|
|
<0.001/<0.001 |
None |
53.2 |
58.7 |
60.4 |
67.2 |
|
44.4 |
52.9 |
65.5 |
76.1 |
|
Ex |
15.6 |
11.6 |
12.9 |
10.8 |
|
15.0 |
15.0 |
12.0 |
9.2 |
|
Light |
11.2 |
11.2 |
11.3 |
10.0 |
|
14.3 |
12.2 |
10.6 |
6.7 |
|
Heavy |
20.0 |
18.5 |
15.4 |
12.0 |
|
26.3 |
19.9 |
11.9 |
8.0 |
|
Exercise, % |
|
|
|
|
0.028/0.005 |
|
|
|
|
0.053/0.028 |
None |
77.0 |
79.2 |
79.0 |
81.7 |
|
79.2 |
77.2 |
78.6 |
82.2 |
|
1–3/wk |
12.4 |
11.4 |
13.3 |
11.1 |
|
11.7 |
12.6 |
12.9 |
11.0 |
|
4–7/wk |
10.6 |
9.4 |
7.7 |
7.2 |
|
9.1 |
10.2 |
8.5 |
6.8 |
|
FBS, mg/dL |
88.8±23.9 |
85.9±14.4 |
85.4±19.2 |
83.3±13.2 |
<0.001/<0.001 |
87.6±22.4 |
86.5±17.1 |
85.4±18.2 |
84.0±14.3 |
<0.001/<0.001 |
Fasting insulin, µU/mL |
7.71±4.36 |
8.52±5.84 |
8.29±6.53 |
8.06±5.44 |
0.008/0.569 |
7.48±4.43 |
8.26±5.74 |
8.44±5.55 |
8.35±6.42 |
<0.001/<0.001 |
HbA1c, % |
5.98±1.07 |
5.85±0.90 |
5.82±0.93 |
5.75±0.88 |
<0.001/<0.001 |
5.94±1.06 |
5.86±0.91 |
5.81±0.93 |
5.78±0.88 |
<0.001/<0.001 |
HOMA-IR |
1.76±1.99 |
1.82±1.31 |
1.77±1.51 |
1.67±1.22 |
0.132/0.122 |
1.65±1.18 |
1.81±2.00 |
1.80±1.31 |
1.75±1.45 |
0.074/0.039 |
Total cholesterol, mg/dL |
188.6±36.6 |
186.2±35.1 |
185.9±33.1 |
183.6±34.0 |
0.008/<0.001 |
185.0±35.2 |
186.4±34.2 |
186.6±35.1 |
186.1±34.6 |
0.723/0.765 |
Triglyceride, mg/dL |
173.8±111.6 |
165.4±107.4 |
165.9±112.5 |
157.9±100.1 |
0.006/0.001 |
168.7±107.3 |
171.4±116.3 |
163.8±101.7 |
159.2±105.7 |
0.033/0.008 |
HDL-C, mg/dL |
44.4±10.3 |
44.3±10.1 |
44.7±10.3 |
44.5±9.9 |
0.861/0.495 |
44.9±10.5 |
43.8±10.1 |
44.5±9.8 |
44.7±10.1 |
0.051/0.761 |
AST, IU/L |
32.5±30.8 |
30.5±16.2 |
30.0±13.1 |
28.2±12.9 |
<0.001/<0.001 |
32.4±28.2 |
30.8±20.5 |
29.2±15.3 |
27.7±10.5 |
<0.001/<0.001 |
ALT, IU/L |
30.0±27.8 |
28.9±27.8 |
26.8±18.5 |
24.4±13.4 |
<0.001/<0.001 |
29.1±22.6 |
29.5±25.8 |
27.3±26.3 |
24.1±13.6 |
<0.001/<0.001 |
Creatinine, mg/dL |
0.84±0.20 |
0.82±0.21 |
0.81±0.15 |
0.78±0.13 |
<0.001/<0.001 |
0.84±0.20 |
0.83±0.21 |
0.80±0.15 |
0.77±0.13 |
<0.001/<0.001 |
WBC, ×103/mL |
6.64±1.82 |
6.52±1.83 |
6.36±1.79 |
6.26±1.82 |
<0.001/<0.001 |
6.74±1.85 |
6.53±1.80 |
6.37±1.84 |
6.14±1.74 |
<0.001/<0.001 |
CRP, mg/dL |
0.29±0.74 |
0.23±0.39 |
0.26±0.83 |
0.22±0.50 |
0.448a/0.216 |
0.25±0.47 |
0.28±0.77 |
0.26±0.84 |
0.22±0.36 |
0.417a/0.318 |
Table 2.Linear regression analysis between FVC and FEV1 and clinical correlates
Factor |
FVC
|
FEV1
|
Univariate
|
Multivariatea
|
Univariate
|
Multivariatea
|
Beta-coeff |
SE |
P value |
Beta-coeff |
SE |
P value |
Beta-coeff |
SE |
P value |
Beta-coeff |
SE |
P value |
Age, yr |
0.108 |
0.028 |
<0.001 |
0.149 |
0.03 |
<0.001 |
0.192 |
0.033 |
<0.001 |
0.236 |
0.035 |
<0.001 |
Male sex |
–4.461 |
0.484 |
<0.001 |
–3.951 |
0.842 |
<0.001 |
–10.843 |
0.558 |
<0.001 |
–6.863 |
0.972 |
<0.001 |
BMI, kg/m2
|
–0.243 |
0.075 |
0.001 |
–0.218 |
0.082 |
0.008 |
0.205 |
0.089 |
0.021 |
0.013 |
0.095 |
0.890 |
WC, cm |
–0.094 |
0.028 |
0.001 |
|
|
|
–0.008 |
0.033 |
0.806 |
|
|
|
Hip circumference, cm |
–0.109 |
0.040 |
0.006 |
|
|
|
–0.058 |
0.047 |
0.221 |
|
|
|
WH ratio, % |
–7.801 |
3.870 |
0.044 |
|
|
|
5.205 |
4.603 |
0.258 |
|
|
|
SBP, mm Hg |
–0.036 |
0.013 |
0.005 |
–0.034 |
0.014 |
0.013 |
–0.010 |
0.015 |
0.490 |
–0.038 |
0.016 |
0.018 |
DBP, mm Hg |
–0.087 |
0.021 |
<0.001 |
|
|
|
–0.071 |
0.025 |
0.005 |
|
|
|
Smoking |
|
|
|
|
|
|
|
|
|
|
|
|
Ex |
–3.419 |
0.751 |
<0.001 |
0.793 |
0.986 |
0.421 |
–8.399 |
0.867 |
<0.001 |
–2.041 |
1.138 |
0.073 |
Light |
–1.985 |
0.801 |
0.013 |
1.404 |
0.976 |
0.150 |
–9.469 |
0.924 |
<0.001 |
–3.587 |
1.127 |
0.001 |
Heavy |
–4.016 |
0.679 |
<0.001 |
0.349 |
0.961 |
0.716 |
–12.095 |
0.783 |
<0.001 |
–4.600 |
1.109 |
<0.001 |
Exercise, /wk |
|
|
|
|
|
|
|
|
|
|
|
|
1–3 |
–0.521 |
0.750 |
0.487 |
|
|
|
–0.719 |
0.891 |
0.419 |
|
|
|
4–7 |
–2.614 |
0.867 |
0.003 |
|
|
|
–2.348 |
1.032 |
0.023 |
|
|
|
FBS, mg/dL |
–0.091 |
0.014 |
<0.001 |
|
|
|
–0.084 |
0.016 |
<0.001 |
|
|
|
Fasting insulin, μU/mL |
0.046 |
0.044 |
0.301 |
|
|
|
0.170 |
0.052 |
0.001 |
|
|
|
HbA1c, % |
–1.359 |
0.255 |
<0.001 |
–1.244 |
0.264 |
<0.001 |
–1.261 |
0.303 |
<0.001 |
–1.354 |
0.305 |
<0.001 |
HOMA-IR |
–0.221 |
0.163 |
0.175 |
|
|
|
0.233 |
0.193 |
0.229 |
|
|
|
Total cholesterol, mg/dL |
–0.019 |
0.007 |
0.007 |
–0.017 |
0.007 |
0.020 |
0.011 |
0.008 |
0.182 |
–0.004 |
0.009 |
0.610 |
Triglyceride, mg/dL |
–0.008 |
0.002 |
0.001 |
0.002 |
0.002 |
0.377 |
–0.007 |
0.003 |
0.005 |
0.003 |
0.003 |
0.232 |
HDL-C, mg/dL |
0.005 |
0.024 |
0.824 |
|
|
|
0.013 |
0.028 |
0.643 |
|
|
|
AST, IU/L |
–0.067 |
0.012 |
<0.001 |
–0.065 |
0.020 |
0.001 |
–0.086 |
0.015 |
<0.001 |
–0.068 |
0.023 |
0.003 |
ALT, IU/L |
–0.061 |
0.011 |
<0.001 |
0.012 |
0.018 |
0.492 |
–0.069 |
0.013 |
<0.001 |
0.036 |
0.020 |
0.076 |
Creatinine, mg/dL |
–11.016 |
1.355 |
<0.001 |
–6.004 |
1.521 |
<0.001 |
–17.714 |
1.600 |
<0.001 |
–5.396 |
1.756 |
0.002 |
WBC, ×103/mL |
–0.618 |
0.133 |
<0.001 |
–0.260 |
0.141 |
0.065 |
–1.220 |
0.157 |
<0.001 |
–0.588 |
0.163 |
<0.001 |
CRP, mg/dL |
–0.884 |
0.379 |
0.020 |
–0.674 |
0.377 |
0.074 |
–0.750 |
0.451 |
0.096 |
–0.338 |
0.435 |
0.437 |
Table 3.Proportional hazards models of diabetes as a function of quartiles of FVC and FEV1
Variable |
FVC
|
FEV1
|
1st |
2nd |
3rd |
1st |
2nd |
3rd |
Univariate |
1.751 (1.385–2.213) |
1.665 (1.316–2.106) |
1.043 (0.807–1.349) |
1.772 (1.389–2.261) |
1.592 (1.248–2.032) |
1.421 (1.106–1.826) |
Model 1a
|
1.623 (1.277–2.064) |
1.568 (1.234–1.993) |
1.034 (0.797–1.341) |
1.675 (1.299–2.161) |
1.470 (1.142–1.893) |
1.426 (1.105–1.841) |
Model 2b
|
1.389 (1.092–1.768) |
1.390 (1.092–1.768) |
1.016 (0.783–1.318) |
1.452 (1.124–1.877) |
1.358 (1.053–1.751) |
1.430 (1.108–1.846) |
Model 3c
|
1.408 (1.106–1.793) |
1.381 (1.084–1.759) |
1.025 (0.790–1.330) |
1.469 (1.137–1.898) |
1.334 (1.034–1.722) |
1.449 (1.122–1.870) |
Table 4.Panel homeostasis model assessment of insulin resistance results with quartiles of FVC and FEV1 as independent variables
Variable |
FVC
|
FEV1
|
Univariate
|
Multivariate
|
Univariate
|
Multivariate
|
Coefficients (95% CI) |
P valuea
|
Coefficients (95% CI) |
P valueb
|
Coefficients (95% CI) |
P valuea
|
Coefficients (95% CI) |
P valueb
|
1st |
0.095 (0.010 to 0.180) |
0.028 |
0.129 (0.044 to 0.215) |
0.003 |
0.003 (–0.083 to 0.089) |
0.944 |
0.064 (–0.024 to 0.153) |
0.156 |
2nd |
0.127 (0.044 to 0.210) |
0.003 |
0.139 (0.055 to 0.223) |
0.001 |
0.790 (–0.004 to 0.162) |
0.061 |
0.114 (0.029 to 0.199) |
0.009 |
3rd |
0.018 (–0.064 to 0.100) |
0.661 |
0.044 (–0.039 to 0.126) |
0.298 |
0.036 (–0.047 to 0.119) |
0.396 |
0.045 (–0.038 to 0.129) |
0.290 |