Proceedings of The Physiological Society

Physiology 2015 (Cardiff, UK) (2015) Proc Physiol Soc 34, C22

Oral Communications

Impact of LGI diet and exercise during experimental obese pregnancy on maternal and offspring cardiometabolic disorders

N. Maicas Blasco1, E. Lovegrove1, E. Domfeh1, A. Samuelsson1, P. Taylor1, L. Poston1

1. Women's Health, King's College London, London, United Kingdom.

The establishment of developmental programming has identified the intrauterine environment as a target for intervention to reduce the adverse effects of maternal obesity and the risk for childhood obesity and cardiometabolic disease in later life. We assessed the impact of low glycaemic index diet (LGI) and physical activity (phys) in obese pregnant rats on maternal and offspring physiological and biochemical parameters. At gestational day (GD) 7, control and high-fat fed obese rats were assigned either to Con (n=10), Ob (n=9) or Ob-phys-LGI (n=8) groups. Exercise was kept until GD 17 and LGI diet until day 14 of lactation. Offspring (Off) were followed until 3 months. Glucose tolerance test was performed and systolic (SBP) and mean arterial (MAP) pressure were measured by radiotelemetry in isoflurane anesthetized rats. Blood was collected from the tail or by cardiac puncture in CO2 sacrificed animals. Values represented as mean±SEM, using ANOVA or Mann-Whitney. Dams in Ob-phys-LGI group showed a reduction in gestational weight gain compared to Ob dams (46±19.2 vs 78±11g;p<0.001). At the end of pregnancy, Ob dams were insulin resistant (HOMA:72±22.3 vs 23±2.6;p<0.05) and had enhanced levels of serum leptin (11850±1743 vs 4235±698.7pg/mL;p<0.001) and adipose tissue (10.9±0.9 vs 4.2±0.8g;p<0.001) compared to Con dams. Intervention led to reversal of fat pad mass (4.9±0.7g;p<0.001) and serum leptin (5004±845.2pg/mL;p<0.01). Maternal body weight (b.w.) gain during lactation in Ob dams was decreased when compared to Con group (-28±13 vs 33±7.4g;p<0.001). This decrease was reversed by the intervention (31±7.8g;p<0.001). From weaning until 3 months, the b.w. gain of OffOb showed a trend to increase when compared to OffCon (males:441±11 vs 414±7.8g, females:229±4.2 vs 218±4.3g). The increase in b.w. was less pronounced in OffOb-phys-LGI, without reaching statistical significance (males:419±6.5g, females:218±6.6g). Female OffOb had increased retroperitoneal fat (3.4±0.3 vs 2.3±0.3g;p<0.05) and impaired glucose tolerance (AUC:1166±44.9 vs 1046±33.1;p<0.05) when compared to OffCon, with a trend to be less pronounced in female OffOb-phys-LGI (2.5±0.3g and 1075±27.0;p>0.05). With regard to cardiovascular parameters, female OffOb displayed an increase of MAP and SBP compared to female OffCon (MAP:104.2±1.2 vs 99.5±1.4mmHg. SBP:122.6±2.0 vs 114.9±2.5mmHg;p<0.05). Male OffOb showed an increase in MAP in comparison with male OffCon (107.6±1.6 vs 102.2±1.7mmHg) which reached statistical significance in the active (nocturnal) phase (p<0.05). No significant differences were observed in the intervention group. These data show that obese pregnant rats develop insulin resistance with increased fat mass and serum leptin levels. LGI diet combined with exercise improved the phenotype observed in obese pregnant rats but without a significant effect on adiposity or cardiovascular parameters in 3-month offspring of obese dams.

Where applicable, experiments conform with Society ethical requirements