The effect of lactational low protein diet on skeletal muscle during adulthood and ageing in male and female mouse offspring

Sarcopenia is characterised by loss of skeletal muscle mass and function associated with a reduction in muscle fibres. External factors, like exercise and diet, can also influence skeletal muscle mass and contribute to muscle fibre loss. Maternal programming refers to the effect of maternal environmental factors such as nutrition that lead to phenotypic changes in the offspring. Maternal malnutrition has been linked to a reduction in body weight and impaired development of skeletal muscle of the offspring; however, there are no studies that reported the long-term effect of maternal low protein diet on the ageing of skeletal muscles. This study aimed to examine how maternal protein deficiency during lactation affects skeletal muscle development and ageing in the offspring. Pups born from normally fed mothers were lactated by low protein fed mothers. Post-weaning, mice were either maintained on a low protein diet (LPD) or switched to normal protein diet (NPD). Pups born from normally fed mothers and maintained on NPD during lactation and afterwards were used as control. In males, the diet mainly affected the size of the myofibres without major effect on fibre number and led to a reduced grip strength of ageing mice (24 months). Female mice had a lower body and muscle weight at weaning but caught up with control mice at 3 months. During ageing, muscle weight, myofibre number and survival rate of female pups were significantly affected. These findings highlight longitudinal animal research for nutritional programming and the importance of sexual dimorphism in response to challenges. Highlights Postnatal low protein diet significantly decreases the survival rate of female but not male mice. During ageing, female mice fed a low protein diet during lactation have lower muscle weight. During ageing, female mice fed a low protein diet postnatally maintain their myofibre number. Male mice fed a low protein diet postnatally have lower body weight and muscle weight throughout their lifespan. Low protein diet affects myofibres size of TA muscle of male but not female mice at 3 months of age however this effect is lost during ageing.