Cardiovascular and Renal Impairment in a Model of Pregnancy During Refeeding After Exposure to a Period of Severe Food Restriction

Background: Acute severe food restriction (sFR) can impair cardiovascular and renal function. Less understood are the long-term adverse consequences to cardiac and renal health after body weight (BW) has recovered due to refeeding including in women who become pregnant during refeeding. Aim: Assess cardiac and renal function in post-partum sFR-Refed rats that become pregnant months after BW recovered due to refeeding as well as on their pregnancy outcomes. Methods: Female Sprague-Dawley rats (3 months old) were fed normal chow ad libitum (Ctrl) or a 60% caloric-restricted (sFR) diet for 2 weeks before being maintained on normal chow ad libitum (sFR-Refed) . Breeding was started after two months of refeeding. Heart and kidney function were analyzed by precision ultrasound during the late pregnancy period from day 19 to 21. After imaging, the animals were infused with Evan’s blue for blood volume determination. Results: After 2 weeks of sFR, rats lost ~20% of their initial BW [DFinal/Initial: Ctrl, 7.1±2.5 vs sFR, -21.5±1.3; p<0.001; n=17]. Although BW increased after 2 months of refeeding, BW gain was lower in the sFR-Refed pregnant group[DFinal/Initial: Ctrl, 44.9±2.3 vs sFR-Refed, 36.9±2.8; p<0.05; n=7-8]. The number of pups [Litter #: Ctrl, 10.5±1.2 vs sFR-Refed, 13.5±1.0; p>0.05; n=4] and average pup weight [gm: Ctrl, 4.92±0.60 vs sFR-Refed, 4.52±0.50; p>0.05; n=4] were not different nor were there effects on the mother's placenta, kidney, and heart weights. However, cardiac output was lower [mL/min: Ctrl, 91.6±5.1 vs sFR-Refed, 74.7±4.1; p<0.05; n=7-8] and renal artery blood flow was reduced [mL/min: Ctrl, 210±12 vs sFR-Refed, 170±11; p<0.05; n=8] in sFR-Refed pregnant compared to Ctrl pregnant rats. Blood volume was also reduced in the pregnant sFR-Refed group [mL: Ctrl, 16.6 ± 1.6 vs sFR-Refed, 8.7 ± 2.0; p<0.05; n=3-4]. Conclusion: These findings suggest that prior exposure to sFR can inhibit blood volume expansion that normally occurs during pregnancy and impair cardiac and renal function post-partum. Further research is needed to understand how women who are subjected either voluntarily (e.g., crash diets) or involuntarily (e.g., very low food security) to prior periods of inadequate caloric intake could be at increased risk for cardiovascular and renal disease later-in-life. AHA: 940246 (AS); KL2: KL2TR001432 (AS); Marriott Award: EG400066 (AS); DOD: W81XWH2110201 (AS). This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.