Titanium dioxide nanoparticles (TiO2 NPs) were usually consumed with a high content of sugar, and children were identified as having the highest exposures due to sweet food preferences. Research on the combined effect of ingested TiO2 NPs and glucose has great significance, particularly in young people. We examined young Sprague-Dawley rats administered TiO2 NPs (0, 2, 10 and 50 mg/kg) orally with and without glucose (1.8 g/kg) for 90 days. Blood glucose homeostasis was assessed by monitoring blood glucose and detecting glycoproteins. Glucose tolerance was also evaluated by the oral glucose tolerance test. The levels of blood glucose-related hormones such as insulin, C-peptide and glucagon were measured. We found that subchronic co-exposure of TiO2 NPs and glucose caused slight imbalance of blood glucose homeostasis in vivo. Mild and temporary hypoglycemia, impaired glucose tolerance and changes of glucose-regulating hormones were shown in the exposure groups. The combined effect of TiO2 NPs and glucose was more apparent than that of TiO2 NPs alone, which may be due to the effects of excess glucose and the interactions between TiO2 NPs and glucose. The antagonistic effect of TiO2 NPs with glucose did exist in the level of glycosylated hemoglobin in female rats. Gender differences were apparent in these effects induced by TiO2 NPs and glucose. Female rats seemed to be more susceptible for blood glucose disorders. Co-exposure of TiO2 NPs and excessive glucose could induce gender-dependent imbalance of blood glucose homeostasis in rats. It may be the reason that these consumers face greater health risks glycosylated hemoglobin.
Keywords: blood glucose homeostasis; combined effect; gender difference; nanotoxicology; titanium dioxide nanoparticles.
© 2020 John Wiley & Sons, Ltd.