Table 6.

Effects of age and body composition (lean tissue and fat) on BMR, V̇O2max andO2sum in deer mice from 27 to 1827 days old

VariableFat and lean (absolute values)Fat and lean (fractions of body mass)
BMRFatr=0.312, P=0.0228r=-0.096, P=0.499
Lean tissuer=0.321, P=0.0191r=-0.106, P=454
Ager=0.150, P=0.283r=0.038, P=0.787
O2max Fatr=0.401, P=0.00295*r=0.237, P=0.091
Lean tissuer=0.505, P=0.000113*r=0.203, P=0.149
Ager=-0.101, P=0.470r=-0.227, P=0.106
O2sum Fatr=0.437, P=0.00107*r=-0.014, P=0.920
Lean tissuer=0.423, P=0.00161*r=-0.065, P=0.646
Ager=-0.14, P=0.315r=-0.214, P=0.127
  • BMR, basal metabolic rate; O2max, maximal oxygen consumption in exercise; O2sum, maximal oxygen consumption in thermogenesis.

    Regressions were performed across all ages. Regression coefficients (r) and P values for fat and lean tissue content were computed from absolute tissue mass and as fractions of whole body mass; in the latter case, regressions also included whole body mass (r and P values not shown). P values significant after Bonferroni correction are indicated with an asterisk (adjusted α=0.0038 for all ages combined).