Table 3. Regression equations, explanation coefficient (r²) and lower limits for CO diffusion, CO diffusion constant and alveolar volume in the reference population of the female and male genders.

Female, 21-92 years, 140-176 cm height, white race (n = 120)
	Height coefficient	Age coefficient	Constant	r2 adjusted	5th residue percentile	Lower limit
DCO (ml/min/mmHg)	0.244	- 0.087	- 15.32	0.53	4.18	P-4.18
VA (L)	0.058	---------	- 5.06	0.40	0.83	P-0.83
KCO (ml. min-1. mmHg-1. L-1)	0.019	---------	+ 0.98	0.05	1.05	P-1.05
Male, 25-88 years, 156-189 cm height, white race (n = 120)
	Height coefficient	Age coefficient	Constant	r2 adjusted	5th residue percentile	Lower limit
DCO (ml/min/mmHg)	0.335	- 0.148	- 22.48	0.60	5.00	P-5.00
VA (L)	0.091	---------	- 9.76	0.56	1.00	P-1.00
KCO (ml. min-1. mmHg-1. L-1)	-------	- 0.019	5.03	0.25	0.82	P-0.82