Osteotropic Effect of Parenteral Obesity in Programmed Male Rats Fed a Calorically Differentiated Diet during Growth and Development

SIMPLE SUMMARY: Parental obesity affects skeletal metabolism in offspring. This relationship is called “nutritional programming”. During the weaning period, they are more highly mineralized and mechanically resistant. It was interesting for us whether changing or continuing the feeding of male offspring with a standard or high-energy diet may have different metabolic effects on bone tissue. Our previous studies on females have shown that the beneficial direction of change is the replacement of the standard diet with a high-energy diet; the reduction of the caloric content of food (change from a high-energy to a properly balanced diet) leads to disorders of skeletal growth and development. In males, any change in diet inhibited skeletal development, and the bones were weaker. The most effective was the continuation of high-energy nutrition, which, in males at 49 and 90 days of age, was manifested by stronger bones. This proves that males and females react differently to a change in the caloric content of the diet during the period of growth and development. ABSTRACT: The experiment was undertaken to assess whether the continuation or change of the parents’ diet affects the previously programmed bone metabolism of the male offspring during its growth and development. A total of 16 male and 32 female Wistar rats were divided into groups and fed a standard (diet S) or high-energy (diet F). After the induction of obesity, the rats from groups S and F, as the parent generation, were used to obtain male offspring, which were kept with their mothers until the weaning day (21 days of age). In our earlier study, we documented the programming effects of the diet used in parents on the skeletal system of offspring measured on the weaning day. Weaned male offspring constitute one control group—parents and offspring fed the S diet. There were three experimental groups, where: parents received diet S and offspring were fed with the F diet; parents were treated with the diet F, while offspring received the S diet; and parents and offspring were fed with the diet F. The analyses were performed at 49 and 90 days of life. After sacrifice, cleaned-off soft tissue femora were assessed using peripheral quantitative computed tomography (pQCT), dual X-ray absorptiometry (DXA), and a three-point bending test. We observed that changing and continuation of nutrition, applied previously in parents, significantly influenced the metabolism of the bone tissue in male offspring, and the osteotropic effects differed, depending on the character of the nutrition modification and age. Additionally, an important conclusion of our study, regarding the previous, is that nutrition modification, affecting the metabolism of bone tissue, also depends on the sex.