J Clin Med Res

Journal of Clinical Medicine Research, ISSN 1918-3003 print, 1918-3011 online, Open Access

Article copyright, the authors; Journal compilation copyright, J Clin Med Res and Elmer Press Inc

Journal website http://www.jocmr.org

Original Article

Volume 8, Number 2, February 2016, pages 105-110

Influence of Body Composition on Lung Function and Respiratory Muscle Strength in Children With Obesity

**Table 1.** Anthropometric Characteristics and Body Composition of Children With Obesity and Those in Ideal Weight Range Stratified by Gender
	Obesity	Ideal weight range	P
Data expressed as mean ± standard deviation or median and interquartile range. BMI: body mass index; WC: waist circumference. *P < 0.05, significant difference between children with obesity and those in ideal weight range.
Male	n = 24	n = 16
Age	7.75 ± 1.53	7.81 ± 1.27	0.22
Body mass (kg)	41.96 ± 8.21*	29.93 ± 7.08	< 0.0001
Height (m)	134.72 ± 7.98	132.93 ± 10.06	0.53
BMI (kg/m²)	23.10 ± 3.54	16.68 ± 1.88	< 0.0001
BMI z score	2.74 ± 0.60*	1.00 ± 0.57	< 0.0001
WC (cm)	79.56 ± 7.58*	62.12 ± 6.83	< 0.0001
Lean mass, kg	30.36 ± 5.76*	25.27 ± 4.56	0.0026
Fat mass, kg	11.75 (9.6 - 14.2)*	4.2 (9.6 - 14.2)	< 0.0001
Lean mass, %	71.45 (67.9 - 75.55)*	83.45 (83.17 - 89.17)	< 0.0001
Fat mass, %	28.55 (24.45 - 32.1)*	14.55 (10.82 - 16.22)	< 0.0001
Female	n = 16	n = 19
Age	8.12 ± 1.5	8.33 ± 1.28	0.83
Body mass (kg)	43.93 ± 10.31*	29.5 ± 4.92	< 0.0001
Height (m)	132 ± 9.84	133 ± 8.95	0.83
BMI (kg/m²)	23.8 ± 3.18	16.44 ± 1.29	< 0.0001
BMI z score	2.59 ± 0.49*	0.49 ± 0.43	< 0.0001
WC (cm)	79.75 ± 8.82*	62.83 ± 4.04	< 0.0001
Lean mass, kg	29.6 (25.3 - 34.3)*	23.9 (20.7 - 28.7)	0.01
Fat mass, kg	12.6 (10.6 - 14.7)*	4.4 (3.1 - 5.37)	< 0.0001
Lean mass, %	71.4 (67.9 - 75.5)	85.4 (83.1 - 89.1)*	< 0.0001
Fat mass, %	30.1 (28.62 - 34.8)*	14.85 (10.15 - 18.15)	< 0.0001

Table 1. Anthropometric Characteristics and Body Composition of Children With Obesity and Those in Ideal Weight Range Stratified by Gender

Obesity

Ideal weight range

Data expressed as mean ± standard deviation or median and interquartile range. BMI: body mass index; WC: waist circumference. *P < 0.05, significant difference between children with obesity and those in ideal weight range.

Male

n = 24

n = 16

Age

7.75 ± 1.53

7.81 ± 1.27

0.22

Body mass (kg)

41.96 ± 8.21*

29.93 ± 7.08

< 0.0001

Height (m)

134.72 ± 7.98

132.93 ± 10.06

0.53

BMI (kg/m²)

23.10 ± 3.54

16.68 ± 1.88

< 0.0001

BMI z score

2.74 ± 0.60*

1.00 ± 0.57

< 0.0001

WC (cm)

79.56 ± 7.58*

62.12 ± 6.83

< 0.0001

Lean mass, kg

30.36 ± 5.76*

25.27 ± 4.56

0.0026

Fat mass, kg

11.75 (9.6 - 14.2)*

4.2 (9.6 - 14.2)

< 0.0001

Lean mass, %

71.45 (67.9 - 75.55)*

83.45 (83.17 - 89.17)

< 0.0001

Fat mass, %

28.55 (24.45 - 32.1)*

14.55 (10.82 - 16.22)

< 0.0001

Female

n = 16

n = 19

Age

8.12 ± 1.5

8.33 ± 1.28

0.83

Body mass (kg)

43.93 ± 10.31*

29.5 ± 4.92

< 0.0001

Height (m)

132 ± 9.84

133 ± 8.95

0.83

BMI (kg/m²)

23.8 ± 3.18

16.44 ± 1.29

< 0.0001

BMI z score

2.59 ± 0.49*

0.49 ± 0.43

< 0.0001

WC (cm)

79.75 ± 8.82*

62.83 ± 4.04

< 0.0001

Lean mass, kg

29.6 (25.3 - 34.3)*

23.9 (20.7 - 28.7)

0.01

Fat mass, kg

12.6 (10.6 - 14.7)*

4.4 (3.1 - 5.37)

< 0.0001

Lean mass, %

71.4 (67.9 - 75.5)

85.4 (83.1 - 89.1)*

< 0.0001

Fat mass, %

30.1 (28.62 - 34.8)*

14.85 (10.15 - 18.15)

< 0.0001

**Table 2.** Maximum Respiratory Pressures (MIP and MEP) Among Children With Obesity and Those in Ideal Weight Range
	Boys	Girls
MIP: maximum inspiratory pressure; MEP: maximum expiratory pressure.
Obese (n = 40)	70.8 ± 27.67	76.74 ± 11.42	72.00 ± 24.32	75.49 ± 11.17	72.5 ± 28.63	67.05 ± 9.93	71.25 ± 30.74	66.66 ± 9.41
Ideal weight (n = 35)	80.62 ± 21.43	70.34 ± 12.54	81.87 ± 18.24	77.78 ± 8.89	72.94 ± 19.68	60.44 ± 6.78	70.00 ± 16.48	65.55 ± 7.73

Table 2. Maximum Respiratory Pressures (MIP and MEP) Among Children With Obesity and Those in Ideal Weight Range

Boys

Girls

MIP obtained (cm H₂O)

MIP predicted (cm H₂O)

MEP obtained (cm H₂O)

MEP predicted (cm H₂O)

MIP obtained (cm H₂O)

MIP predicted (cm H₂O)

MEP obtained (cm H₂O)

MEP predicted (cm H₂O)

MIP: maximum inspiratory pressure; MEP: maximum expiratory pressure.

Obese (n = 40)

70.8 ± 27.67

76.74 ± 11.42

72.00 ± 24.32

75.49 ± 11.17

72.5 ± 28.63

67.05 ± 9.93

71.25 ± 30.74

66.66 ± 9.41

Ideal weight (n = 35)

80.62 ± 21.43

70.34 ± 12.54

81.87 ± 18.24

77.78 ± 8.89

72.94 ± 19.68

60.44 ± 6.78

70.00 ± 16.48

65.55 ± 7.73

**Table 3.** Spirometric Measures of Children With Obesity and Those in Ideal Weight Range
	Obese	Ideal weight	P-value
Data expressed as mean and standard deviation. SVC: slow vital capacity; IRV: inspiratory reserve volume; IC: inspiratory capacity; ERV: expiratory reserve volume; FVC: forced vital capacity; FEV₁: forced expiratory volume in the first second; MVV: maximum voluntary ventilation. *P < 0.05, significant difference between obese and ideal weight groups.
Male
SVC (%P)	99.41 ± 11.05	108.31 ± 12.77*	0.03
IRV (L)	0.93 ± 0.33	1.00 ± 0.44	0.10
IC (L)	1.51 ± 0.25	1.58 ± 0.43	0.30
EVR (L)	0.45 ± 0.27	0.56 ± 0.21	0.24
FVC (% P)	101.82 ± 12.07	103.87 ± 11.21	0.61
FEV₁ (% P)	93.76 ± 9.78	99.87 ± 9.72*	0.04
FEV₁/FVC (%P)	92.29 ± 3.38	96.31 ± 4.82*	0.002
MVV (%P)	73.23 ± 12.76	77.25 ± 18.08	0.46
Female
SVC (%P)	96.81 ± 10.50	93.5 ± 8.18	0.31
IRV (L)	0.89 ± 2.66	0.83 ± 2.27	0.55
IC (L)	1.43 ± 0.34	1.30 ± 0.17	0.05
EVR (L)	0.47 ± 0.41	0.47 ± 0.24	0.96
FVC (%P)	96.81 ± 11.89	11.89 ± 8.98	0.86
FEV₁ (%P)	89.87 ± 9.81	89.94 ± 9.13	0.98
FEV₁/FVC (%P)	91.37 ± 6.94	93.5 ± 5.81	0.46
MVV (%P)	67.06 ± 14.01	73.5 ± 14.17	0.19

Table 3. Spirometric Measures of Children With Obesity and Those in Ideal Weight Range

Obese

Ideal weight

P-value

Data expressed as mean and standard deviation. SVC: slow vital capacity; IRV: inspiratory reserve volume; IC: inspiratory capacity; ERV: expiratory reserve volume; FVC: forced vital capacity; FEV₁: forced expiratory volume in the first second; MVV: maximum voluntary ventilation. *P < 0.05, significant difference between obese and ideal weight groups.

Male

SVC (%P)

99.41 ± 11.05

108.31 ± 12.77*

0.03

IRV (L)

0.93 ± 0.33

1.00 ± 0.44

0.10

IC (L)

1.51 ± 0.25

1.58 ± 0.43

0.30

EVR (L)

0.45 ± 0.27

0.56 ± 0.21

0.24

FVC (% P)

101.82 ± 12.07

103.87 ± 11.21

0.61

FEV₁ (% P)

93.76 ± 9.78

99.87 ± 9.72*

0.04

FEV₁/FVC (%P)

92.29 ± 3.38

96.31 ± 4.82*

0.002

MVV (%P)

73.23 ± 12.76

77.25 ± 18.08

0.46

Female

SVC (%P)

96.81 ± 10.50

93.5 ± 8.18

0.31

IRV (L)

0.89 ± 2.66

0.83 ± 2.27

0.55

IC (L)

1.43 ± 0.34

1.30 ± 0.17

0.05

EVR (L)

0.47 ± 0.41

0.47 ± 0.24

0.96

FVC (%P)

96.81 ± 11.89

11.89 ± 8.98

0.86

FEV₁ (%P)

89.87 ± 9.81

89.94 ± 9.13

0.98

FEV₁/FVC (%P)

91.37 ± 6.94

93.5 ± 5.81

0.46

MVV (%P)

67.06 ± 14.01

73.5 ± 14.17

0.19

**Table 4.** Multiple Linear Regression Among Anthropometric Data, Body Composition, Spirometric Variables and Respiratory Muscle Strength
	SVC%	ERV	IRV	IC	FVC%	FEV₁%	MVV%
SVC: slow vital capacity; ERV: expiratory reserve volume; IRV: inspiratory reserve volume; IC: inspiratory capacity; FVC: forced vital capacity; FEV₁: forced expiratory volume in the first second; MVV: maximum voluntary ventilation.
Body mass	20.36	0.001	17.63	0.01	24.13	0.001	15.38	0.006	32.20*	0.000	31.33	0.002	20.53	0.006
BMI (kg/m²)	20.25	0.000	17.48	0.008	22.54	0.001	15.39	0.001	32.17	0.000	28.65	0.000	17.30	0.001
BMI z score	10.38	0.005	10.58	0.004	11.96	0.002	23.49	0.007	18.92	0.000	19.14	0.000	12.83	0.002
Fat mass, kg	46.52*	0.000	24.96	0.005	0.38	0.001	15.30	0.000	56.67*	0.000	56.27	0.000	44.13	0.000
Fat mass, %	20.48	0.003	16.29	0.002	7.61	0.000	25.85	0.007	30.19	0.000	29.07	0.000	17.50	0.003
Lean mass, kg	30.03	0.000	20.22	0.014	47.04*	0.000	28.51	0.006	56.25*	0.000	34.36	0.000	21.81	0.008
Lean mass, %	23.06	0.002	16.33	0.005	19.62	0.000	18.81	0.013	30.49	0.000	31.24	0.000	17.56	0.003

Table 4. Multiple Linear Regression Among Anthropometric Data, Body Composition, Spirometric Variables and Respiratory Muscle Strength

SVC%

ERV

IRV

FVC%

FEV₁%

MVV%

R²

SVC: slow vital capacity; ERV: expiratory reserve volume; IRV: inspiratory reserve volume; IC: inspiratory capacity; FVC: forced vital capacity; FEV₁: forced expiratory volume in the first second; MVV: maximum voluntary ventilation.

Body mass

20.36

0.001

17.63

0.01

24.13

0.001

15.38

0.006

32.20*

0.000

31.33

0.002

20.53

0.006

BMI (kg/m²)

20.25

0.000

17.48

0.008

22.54

0.001

15.39

0.001

32.17

0.000

28.65

0.000

17.30

0.001

BMI z score

10.38

0.005

10.58

0.004

11.96

0.002

23.49

0.007

18.92

0.000

19.14

0.000

12.83

0.002

Fat mass, kg

46.52*

0.000

24.96

0.005

0.38

0.001

15.30

0.000

56.67*

0.000

56.27

0.000

44.13

0.000

Fat mass, %

20.48

0.003

16.29

0.002

7.61

0.000

25.85

0.007

30.19

0.000

29.07

0.000

17.50

0.003

Lean mass, kg

30.03

0.000

20.22

0.014

47.04*

0.000

28.51

0.006

56.25*

0.000

34.36

0.000

21.81

0.008

Lean mass, %

23.06

0.002

16.33

0.005

19.62

0.000

18.81

0.013

30.49

0.000

31.24

0.000

17.56

0.003