Programming Effect of the Parental Obesity on the Skeletal System of Offspring at Weaning Day

SIMPLE SUMMARY: Overweight and obesity can cause many diseases, and several studies indicate a close relationship between the obesity of parents and the health of their offspring. Our aim was to investigate whether there is a programming influence of parental obesity on the skeletal system in weaned female and male offspring rats. In undertaking this, analysis of bone material was carried out using isolated tibia, and densitometry (DXA), peripheral (pQCT) and micro (µCT) computed tomography were performed. Mechanical tests and blood serum biochemistry were also carried out. Our work showed a significant programming influence of parental obesity on neonatal skeletal development. The tibiae isolated from offspring originating from obese parents were characterized by more intense mineralization and higher fracture resistance. However, numerous studies demonstrate the destructive effect of obesity on the skeletal system. Our research and the available literature suggest the existence of a “fat threshold”, the exceeding of which changes of the osteotropic effect of adipose tissue to become unfavorable. Therefore, there is a need for further research to determine the time-dependent metabolic relationship between adipose tissue and bone in both animals and humans. ABSTRACT: Our study aimed to verify the hypothesis of the existence of a programming effect of parental obesity on the growth, development and mineralization of the skeletal system in female and male rat offspring on the day of weaning. The study began with the induction of obesity in female and male rats of the parental generation, using a high-energy diet (group F). Females and males of the control group received the standard diet (group S). After 90 days of dietary-induced obesity, the diet in group F was changed into the standard. Rats from groups F and S were mated to obtain offspring which stayed with their mothers until 21 days of age. Tibia was tested using dual-energy X-ray absorptiometry (DXA), peripheral quantitative computed tomography (pQCT), micro-computed tomography (µCT) and mechanical strength using the three-point bending test. Biochemical analysis of blood serum bone metabolism markers was performed. DXA analysis showed higher tibia bone mineral content (BMC) and area. pQCT measurements of cortical and trabecular tissue documented the increase of the volumetric bone mineral density and BMC of both bone compartments in offspring from the F group, while µCT of the trabecular tissue showed an increase in trabecular thickness and a decrease of its separation. Parental obesity, hence, exerts a programming influence on the development of the skeletal system of the offspring on the day of the weaning, which was reflected in the intensification of mineralization and increased bone strength.