Background

Maternal age is on the rise, alongside an increase in childhood obesity. However, relatively few studies have delved into the relationship between maternal age and offspring obesity risk. Here we experimentally investigated the effect of maternal age on offspring susceptibility to diet induced obesity.

Methods

Female C57BL/6 mice (n=22) were continuously bred throughout their lifetime. Two male and two female pups from each mother’s first, fifth and tenth litter were used to represent mothers of a young (3 months), middle (6-8 months) and old age (10-12 months). At 14 weeks old, one male and one female from each litter were fed a high fat diet (HFD; 45%); or control diet (10% fat) for eight weeks. Body mass (BM) was recorded daily. Fat mass and fat free mass were measured by dual x-ray absorptiometry after 8 weeks of diet. Following which the mice were culled and all fat pads were dissected and weighed.

Results

The BM of male and female HFD fed offspring increased rapidly over the diet period. Terminal BM, fat mass and fat free mass was unaffected by maternal age in both male and female offspring fed either HFD or control diet. After accounting for BM however, male offspring of young mothers fed HFD had significantly greater brown adipose tissue (BAT) and subcutaneous fat compared to offspring of middle age (t= 2.4, p=0.02, t=2.3, p=0.025 respectively) and old mothers (t= 2.7, p=0.01, t=3, p=0.005). Female HFD offspring born to young mothers also had significantly greater BAT, subcutaneous and retroperitoneal fat compared to female offspring of middle age (t=4.4, p=0.0001, t=3.8, p=0.0005, t=2.7, p=0.011 respectively) and old mothers (t=3.1, p=0.003, t=2.4, p=0.023, t=2.3, p=0.029 respectively). There was no difference between the offspring of middle age and old mother’s BAT, subcutaneous or retroperitoneal fat. Epididymal fat of male and female offspring was not affected by maternal age.

Conclusions

Overall, maternal age played a role in altering the fat pad sizes in offspring fed HFD.