Int J Clin Pediatr

International Journal of Clinical Pediatrics, ISSN 1927-1255 print, 1927-1263 online, Open Access

Article copyright, the authors; Journal compilation copyright, Int J Clin Pediatr and Elmer Press Inc

Journal website https://www.theijcp.org

Original Article

Volume 11, Number 3, October 2022, pages 76-84

Reduction of Exercise Capacity, Respiratory and Peripheral Muscle Strength in Severe Asthma

Figure 1. Correlation between MST and age, BMI, pulmonary function test, respiratory and peripheral muscle strength. MEP: maximal expiratory pressure; MIP: maximal inspiratory pressure; MST: modified shuttle test; BMI: body mass index.

Figure 2. Group with < Q3 percentile compared to > Q3 on the 6MWT in relation to FVC and FEV₁. 6MWT: 6-min walk test; Q3: 75th percentile. FEV₁: forced expiratory volume at first second of FVC; FVC: forced vital capacity.

**Table 1.** Clinical Characteristics of Patients With Severe Asthma
Variables	N = 30
Data are presented as mean ± SD or n (%). ^an = 23; ^bn = 17; ^c≥ 12 years, n = 11. BMI: body mass index; FEF_25-75: forced expiratory flow at 25-75% of FVC; FEV₁: forced expiratory volume at first second of FVC; FVC: forced vital capacity; PEF: peak expiratory flow; IPAQ: International Physical Activity Questionnaire; PedsQL: Pediatric Quality of Life Inventory Asthma Module.
Female	19 (63.3)
Age, years	10.8 ± 2.88
Anthropometry
Weight, kg	42.8 ± 1.44
Height, m	1.44 ± 0.15
Height, z score	-0.03 ± 1.37
BMI, kg/m²	20.34 ± 3.22
BMI, z score	0.99 ± 1.20
Lung function
FVC, L (%)^a	2.4 ± 0.8 (104.0 ± 10.6)
FEV₁, L (%)^a	2.1 ± 0.7 (101.5 ± 13.5)
FEV₁/FVC^a	87.7 ± 8.3
FEF_25-75, L (%)^b	2.5 ± 1.1 (100.8 ± 37.4)
PEF, L (%)^b	5.7 ± 2.2 (104.9 ± 18.5)
Physical activity (IPAQ)^c
Very active	0 (0.0)
Active	6 (54.5)
Insufficiently active A	4 (36.4)
Insufficiently active B	1 (9.1)
Sedentary	0 (0.0)
Quality of life (PedsQL asthma)
Asthma symptoms	69.7 ± 18.0
Treatment problems	84.3 ± 13.3
Worry	70.8 ± 25.6
Communication	83.1 ± 16.1

Table 1. Clinical Characteristics of Patients With Severe Asthma

Variables

N = 30

Data are presented as mean ± SD or n (%). ^an = 23; ^bn = 17; ^c≥ 12 years, n = 11. BMI: body mass index; FEF_25-75: forced expiratory flow at 25-75% of FVC; FEV₁: forced expiratory volume at first second of FVC; FVC: forced vital capacity; PEF: peak expiratory flow; IPAQ: International Physical Activity Questionnaire; PedsQL: Pediatric Quality of Life Inventory Asthma Module.

Female

19 (63.3)

Age, years

10.8 ± 2.88

Anthropometry

Weight, kg

42.8 ± 1.44

Height, m

1.44 ± 0.15

Height, z score

-0.03 ± 1.37

BMI, kg/m²

20.34 ± 3.22

BMI, z score

0.99 ± 1.20

Lung function

FVC, L (%)^a

2.4 ± 0.8 (104.0 ± 10.6)

FEV₁, L (%)^a

2.1 ± 0.7 (101.5 ± 13.5)

FEV₁/FVC^a

87.7 ± 8.3

FEF_25-75, L (%)^b

2.5 ± 1.1 (100.8 ± 37.4)

PEF, L (%)^b

5.7 ± 2.2 (104.9 ± 18.5)

Physical activity (IPAQ)^c

Very active

0 (0.0)

Active

6 (54.5)

Insufficiently active A

4 (36.4)

Insufficiently active B

1 (9.1)

Sedentary

0 (0.0)

Quality of life (PedsQL asthma)

Asthma symptoms

69.7 ± 18.0

Treatment problems

84.3 ± 13.3

Worry

70.8 ± 25.6

Communication

83.1 ± 16.1

**Table 2.** Comparison Between Predicted and Measured Values of the Tests
Test	Obtained	Predict	% of predict	P value
^aPredicted by reference equation. ^bPredicted by normative values. Data are presented as mean ± SD. 6MWT: 6-min walk test; HS: handgrip strength; MEP: maximal expiratory pressure; MIP: maximal inspiratory pressure; MST: modified shuttle test; PedsQL: Pediatric Quality of Life Inventory Asthma Module.
6MWT (m)	538.0 ± 63.7	640.0 ± 44.1	84.4 ± 11.3^a	< 0.001
MST (m)	748.3 ± 201.4	918.2 ± 134.2	81.5 ± 18.1^a	< 0.001
MIP (cm H₂O)	77.9 ± 24.8	93.4 ± 10.6	83.4 ± 24.6^a	0.002
MEP (cm H₂O)	82.1 ± 17.2	98.4 ± 7.8	83.9 ± 18.2^a	< 0.001
HS (kg)	16.5 ± 5.4	19.1 ± 6.2	88.8 ± 19.3^b	0.003

Table 2. Comparison Between Predicted and Measured Values of the Tests

Test

Obtained

Predict

% of predict

P value

^aPredicted by reference equation. ^bPredicted by normative values. Data are presented as mean ± SD. 6MWT: 6-min walk test; HS: handgrip strength; MEP: maximal expiratory pressure; MIP: maximal inspiratory pressure; MST: modified shuttle test; PedsQL: Pediatric Quality of Life Inventory Asthma Module.

6MWT (m)

538.0 ± 63.7

640.0 ± 44.1

84.4 ± 11.3^a

< 0.001

MST (m)

748.3 ± 201.4

918.2 ± 134.2

81.5 ± 18.1^a

< 0.001

MIP (cm H₂O)

77.9 ± 24.8

93.4 ± 10.6

83.4 ± 24.6^a

0.002

MEP (cm H₂O)

82.1 ± 17.2

98.4 ± 7.8

83.9 ± 18.2^a

< 0.001

HS (kg)

16.5 ± 5.4

19.1 ± 6.2

88.8 ± 19.3^b

0.003

**Table 3.** Correlations Between PedsQL Asthma and Age, BMI, Maximal and Submaximal Exercise Capacity, Peripheral and Respiratory Muscle Strength
Variables	Asthma symptoms	Treatment problems	Worry	Communication
6MWT: 6-min walk test; BMI: body mass index; HS: handgrip strength; MEP: maximal expiratory pressure; MIP: maximal inspiratory pressure; MST: modified shuttle test; PedsQL: Pediatric Quality of Life Inventory Asthma Module.
Age	-0.403	0.027	-0.262	0.162	-0.599	< 0.001	-0.284	0.136
BMI	-0.390	0.033	-0.170	0.370	-0.138	0.467	-0.243	0.204
MST	0.059	0.762	-0.060	0.758	-0.165	0.392	0.134	0.496
6MWT	-0.018	0.926	-0.047	0.805	0.076	0.691	0.177	0.359
MIP	0.141	0.474	0.047	0.813	-0.127	0.519	-0.340	0.083
MEP	-0.338	0.078	-0.398	0.036	-0.249	0.202	-0.053	0.794
HS	-0.522	0.004	-0.287	0.139	-0.504	0.006	-0.308	0.118

Table 3. Correlations Between PedsQL Asthma and Age, BMI, Maximal and Submaximal Exercise Capacity, Peripheral and Respiratory Muscle Strength

Variables

Asthma symptoms

Treatment problems

Worry

Communication

6MWT: 6-min walk test; BMI: body mass index; HS: handgrip strength; MEP: maximal expiratory pressure; MIP: maximal inspiratory pressure; MST: modified shuttle test; PedsQL: Pediatric Quality of Life Inventory Asthma Module.

Age

-0.403

0.027

-0.262

0.162

-0.599

< 0.001

-0.284

0.136

BMI

-0.390

0.033

-0.170

0.370

-0.138

0.467

-0.243

0.204

MST

0.059

0.762

-0.060

0.758

-0.165

0.392

0.134

0.496

6MWT

-0.018

0.926

-0.047

0.805

0.076

0.691

0.177

0.359

MIP

0.141

0.474

0.047

0.813

-0.127

0.519

-0.340

0.083

MEP

-0.338

0.078

-0.398

0.036

-0.249

0.202

-0.053

0.794

-0.522

0.004

-0.287

0.139

-0.504

0.006

-0.308

0.118