(P18-051-23) Prenatal Nitrate Supplementation of Maternal High-Fat Diet Influences Adipose Tissue Development in Offspring From an Obese Pregnancy

Objectives: Excess adiposity during gestation may induce perturbations in offspring that impact adipose tissue (AT) development and long-term cardiometabolic risk. Dietary nitrate is associated with reduced weight gain and visceral fat accrual in adults, yet it is unknown if similar benefits would be imparted to offspring. This study evaluated body composition development in offspring of obese Sprague-Dawley (SD) dams fed a high fat diet with or without inorganic nitrate.

Methods: Eight-week old female SD rats were randomized to 10% normal-fat diet (NFD) (n=4) or 45% high fat diet (HFD) (n=7). Upon obesity confirmation, HFD rats (n=4) were transitioned to a HFD supplemented with inorganic nitrate (HFDN). NFD, HFD, and HFDN rats maintained their respective diets through gestation, lactation, and weaning. At postnatal day 21 (P21), weanling pups from NFD, HFD, and HFDN groups were transitioned to NFD. Pups were euthanized at P21, P42, and P65, representing the weanling, periadolescent, and young adult phases. Bioimpedance spectroscopy (BIS) and mass of visceral white AT (WAT) and brown AT (BAT) were recorded. ANOVA with post hoc testing using Bonferroni correction was employed.

Results: Obesity was confirmed prior to mating in HFD and HFDN rats as evidenced by significantly greater (p < 0.05) body weight and BMI compared to NFD rats. At P21, WAT was significantly lower in pups reared by NFD and HFDN dams compared to those reared by HFD dams (p < 0.001, both). Fat mass assessed by BIS was significantly lower in NFD and HFDN pups compared to HFD pups (p=0.049, p=0.042, respectively). At P42, WAT remained lower in NFD and HFDN pups compared to HFD pups, albeit non-significant (p=0.052). At P65, significant reductions in WAT were observed in NFD and HFDN pups compared to HFD pups (p=0.001, p< 0.001, respectively). Fat mass assessed by BIS was significantly lower in HFDN pups compared to HFD pups (p=0.007). Significant differences (p < 0.05) in BAT were also observed across groups through P65.

Conclusions: Results suggest that prenatal nitrate supplementation may overcome the consequences of an obese pregnancy such that significant differences in body composition were not observed between NFD and HFDN offspring. Additional research is warranted to explore the epigenetic pathways by which nitrate influences AT development.

Funding Sources: Academy of Nutrition and Dietetics