INS and Hyperglycemia: Data on fluoride exposure and glucose metabolism impairments in mammals are rather fragmentary: (1) chronic fluoride exposure results in hyperglycemia accompanying classical symptoms of fluorosis, with diabetogenic effect of fluoride deriving from inhibition of key enzymes in glycolysis and in the Krebs cycle (Grucka-Mamczar et al. 2007); (2) a recent study also indicates that fluoride exposure lowers insulin secretion, consequent to a reduction in insulin mRNA and its secretion from beta-cells).