Table 3.

Effect of OGTT and grouping variables on protein nitration and PARP activation according to mixed models with fixed effects. Difference in ON stress between the fasting and the postload state was assessed by the inclusion of the interaction between time (index) and the given predictors. As the same subjects were observed at two time points, observations are not independent (they are clustered within individuals), thus fixed-effects hierarchical linear specification was used. Both nitrative stress and PARP activity increase by the 2nd hour of the OGTT due to the glucose load (index). In case of tyrosine nitration, previous insulin treatment during index pregnancy significantly decreases the increment (index ∗ previous insulin treatment). PARP activation is not altered by the grouping variables.

Independent variable	log NT	log PAR
Dependent variable
Index	0.33∗∗∗ (0.085)	0.37∗∗ (0.13)
Previous insulin treatment	0.08 (0.43)
Index ∗ previous insulin treatment	−0.65∗∗ (0.28)

N = 86 and 84, respectively. Values are estimated effect sizes: B (SE) (^∗: p ≤ 0.05; ^∗∗: p ≤ 0.01; ^∗∗∗: p ≤ 0.001).