TABLE 2.

Multiple regression models for 24-h average EE (cal/min) in ob/ob mice (n = 28) evaluated in the leptin-deficient state and subsequently evaluated again in the leptin-replaced state

Model for leptin-deficient state
Independent variable	Coefficient* ± SE	P
Intercept	1.989 ± 2.859	0.49
Lean body mass (g)	0.212 ± 0.281	0.46
Fat mass (g)	0.120 ± 0.106	0.27
Model for leptin-replaced state
Intercept	−4.229 ± 4.499	0.36
Leptin (ng/ml)	0.115 ± 0.042	0.01
Lean body mass (g)	0.912 ± 0.373	0.02
Fat mass (g)	−0.086 ± 0.122	0.49

*Estimated change in mean EE per unit change in the independent variable. Separate models were fit within each state. Interpretation: Plasma leptin level and LBM are significant independent determinants of EE in ob/ob mice receiving short-term leptin replacement in the physiological range. In addition to being significant in the leptin-replaced state, the estimated EE cost per gram increase in LBM is over fourfold larger than it was in the leptin-deficient state. By comparison, the contribution of FM to EE in ob/ob mice did not achieve significance in either the presence or absence of leptin administration.