Table 2. Pearson’s correlation coefficient between SMI and parameters of respiratory function and respiratory muscle strength.

	Total (n=77)	Male (n=40)	Female (n=37)
Respiratory function
VC (l)	0.82**	0.50**	0.51**
IRV (l)	0.63**	0.26	0.40*
ERV (l)	0.61**	0.17	0.33*
IC (l)	0.73**	0.41**	0.47**
FVC (l)	0.82**	0.48**	0.44**
FEV1 (l)	0.80**	0.41**	0.35*
PEFR (l/sec)	0.76**	0.34*	0.35*
Respiratory muscle strength
PImax (kPa)	0.56**	0.18	0.13
PIpeak (kPa)	0.58**	0.22	0.17
PEmax (kPa)	0.66**	0.35*	0.27
PEpeak (kPa)	0.69**	0.37*	0.32

Pearson’s correlation coefficient *p<0.05, **p<0.01.