Our group has shown that maternal nicotine exposure (6 mg/kg/day) from day 2 to 16 of lactation causes neonatal hyperleptinemia and primary hypothyroidism and programs for overweight, higher visceral adiposity, adipocyte hypertrophy, hyperleptinemia, leptin and insulin resistance, and secondary hypothyroidism in adult rat offspring (Oliveira et al., 2009; de Oliveira et al., 2010). Here, LEP is linked to hypothyroidism.