Intrauterine growth restriction programs adult metabolic disease, which is exacerbated with “second hits” such as pregnancy and obesity in females born small. Importantly, exercise is reported to have a positive effect in those born small. This study determined if a high fat diet (HFD) exacerbates metabolic dysfunction in pregnant females born small and whether exercise before and during pregnancy is more beneficial in preventing these complications than exercise during pregnancy alone.
Uteroplacental insufficiency was induced by bilateral uterine vessel ligation (Restricted) or sham (Control) surgery on E18 in Wistar-Kyoto rats. Female offspring consumed a chow or HFD (23% fat) from 5 weeks and mated at 20 weeks. Female rats were exercised on treadmills for 4 weeks before pregnancy and throughout pregnancy or during the last two thirds of pregnancy only. A glucose tolerance test was performed (E18) and plasma leptin, intramuscular triglyceride and pancreatic β-cell and islet mass were measured at E20.
Control and Restricted rats exposed to a HFD were heavier with higher plasma leptin concentrations compared to chow-fed rats irrespective of exercise interventions. HFD exacerbated the pre-existing glucose intolerance in Restricted female rats but exercise before and during pregnancy prevented the development of glucose intolerance (p<0.05). Females on a HFD and exercised before and during pregnancy had increased β-cell and islet mass (p<0.05). Compared to Control counterparts, exercise before and during pregnancy reduced intramuscular triglyceride in Restricted chow-fed females (p<0.05). Metabolic dysfunction was not impacted by exercise in pregnancy alone.
In conclusion, females born small are at a greater risk of glucose intolerance when exposed to a HFD but this was prevented by the lifestyle intervention of exercise potentially due to improved β-cell mass. This study also suggests that exercise prior to and during pregnancy is more beneficial in preventing metabolic disease than exercise during pregnancy only.