Table 2. Regression analyses of SP, GR, 11βHSD mRNA expression against birth weight and weight at 21 days and SP mRNA expression against plasma cortisol concentrations on postnatal day 20.

Variables	Equation	N	Adjusted r2	P
SP mRNA expression (MNE) vs. Birth weight (kg)
SP-A	y = 1.84x – 0.23	14	0.565	0.001
SP-B		14	0.205	0.059
SP-C		14	0.108	0.135
SP-D		14	0.099	0.145
GR, 11βHSD mRNA expression (MNE) and plasma cortisol vs. Birth weight (kg)
GR	y = 0.19x – 0.015	14	0.489	0.003
11βHSD-1		13	0.191	0.076
11βHSD-2		13	0.016	0.292
Plasma cortisol concentration		9	0.413	0.062
Lung tissue cortisol concentration		11	-0.0120	0.372
SP mRNA expression (MNE) vs. Weight at 21 days (kg)
SP-A	y = 2.09x – 0.012	15	0.356	0.011
SP-B		15	0.169	0.071
SP-C		15	0.049	0.212
SP-D		15	-0.026	0.436
GR, 11βHSD mRNA expression (MNE) and plasma cortisol vs. Weight at 21 days (kg)
GR	y = 0.228x – 0.001	14	0.582	0.001
11βHSD-1		13	0.092	0.292
11βHSD-2		14	0.051	0.217
Plasma cortisol concentration		10	0.079	0.219
Lung tissue cortisol concentration		11	-0.0976	0.747
SP mRNA expression (MNE) vs plasma cortisol concentration
SP-A		10	0.051	0.259
SP-B		10	0.006	0.830
SP-C		10	0.156	0.259
SP-D		10	1.34E-005	0.992
SP mRNA expression (MNE) vs lung tissue cortisol concentration
SP-A		10	0.146	0.150
SP-B		10	0.038	0.278
SP-C	y = 0.34x + 2.27	10	0.446	0.021
SP-D	y = 0.0092x + 0.026	10	0.4522	0.020

Regression equations are only provided in case of significant relationships. MNE, mean normalised expression.