Exercise Capacity in Unilateral Diaphragm Paralysis: The Effect of Obesity
Table 2
Effect of UDP, obesity, and their combination on static PFTs and exercise parameters.
Not obese
Obese
UDP + Not obese
UDP + Obese
p-value
Static PFT values
FEV-1, absolute value Liters
2.57 +/- 0.93
2.74 +/- 0.65
1.96 +/- 0.80
1.91 +/- 0.58
p=.004
Forced vital capacity % predicted
91 +/- 17
99 +/- 12
67 +/- 17
62.9 +/- 13.5
p<.0001
Total lung capacity % predicted
97 +/- 18
94 +/- 15
74 +/- 14
66.1 +/- 14.0
p=.0002
Functional residual capacity % predicted
99 +/- 21
73 +/- 18
71 +/- 15
53.7 +/- 12.0
p<.0001
DLCO/Alveolar volume % predicted
84 +/- 26
98 +/- 16
103 +/- 14
111.7 +/- 20.3
p=.054
Exercise parameters
O2 uptake, peak exercise ( L/min)
2.01 +/- 0.88
2.33 +/- 0.67
1.85 +/- 0.83
1.57 +/- 0.64
p=.04
Peak minute ventilation, VE (L/min)
76.4 +/- 35.3
78.4 +/- 21.0
66.2 +/- 24.0
54.4 +/- 23.2
p=.06
Breathing Reserve % of predicted VE (max)
16.1 +/- 22.0
15.4 +/- 18.4
-0.81 +/- 21.5
11.9 +/- 19.5
p=.16
Estimated peak work rate (PWR, watts)
132.4 +/- 76.6
149 +/- 74.7
130 +/- 75.8
93.9 +/- 66.2
p=.13
Total exercise time (minutes)
8.5 +/- 2.9
8.1 +/- 2.2
8.9 +/- 3.1
5.7 +/- 2.0
p=.008
Estimated work efficiency at peak exercise (watts/L/min)
64.7 +/- 23.5
61.8 +/- 20.7
68.2 +/- 27.1
51.4 +/- 21.2
p=.23
Anaerobic Threshold % of maximal predicted VO2
64 +/- 18
62 +/- 14
59 +/- 13
44 +/- 17
p=.03
SpO2, resting minus nadir (%)
3.0 +/- 3.6
2.0 +/- 1.9
4.3 +/- 3.3
2.9 +/- 3.8
p=.61
Numerical values are reported as mean +/- standard deviation. UDP = unilateral diaphragm paralysis. -values are based on the Kruskal-Wallis test. Estimated peak work efficiency is calculated as the ratio PWR/VO2peak. Breathing reserve is expressed as the percent reduction in peak VE below the predicted maximal VE. No clear anaerobic threshold could be identified in 8 of the 46 subjects.
