Abstract
Childhood obesity is growing in prevalence. Obesity and bone dysfunctions may be related
disorders, and therefore our aim was to study the impact of the early overfeeding
(EO) in offspring bone health since weaning up to adulthood. To induce EO during lactation,
litter size was adjusted to 3 male rats per litter (SL). Litter containing 10 pups
per mother was the control (NL). Bone tissue was evaluated by dual-energy X-ray absorptiometry,
computed tomography, microcomputed tomography, biomechanical tests, and serum analyses.
SL offspring presented higher body weight, fat mass, lean mass from 21 up to 180 days,
hyperphagia, and higher visceral fat mass. Bone analysis showed that SL offspring
presented higher total bone mineral density (BMD) only at 180 days, and higher total
bone mineral content and higher bone area from 21 until 180 days. At 180 days, SL
offspring presented higher femur BMD and fourth lumbar vertebra (LV4) BMD, higher
femoral head radiodensity and LV4 vertebral body radiodensity, lower trabecular pattern
factor and trabecular separation, however with higher trabecular number, higher maximal
load, resilience, stiffness and break load, and lower break deformation. SL group
had, at 180 days, higher osteocalcin and lower C-terminal cross-linked telopeptide
of type I collagen (CTX I). We have shown that the excess of fat mass contributed
to an increased bone mass, and hypothesized that this increase could be mediated by
the hypothyroidism and previous higher thyroid hormone action and hyperleptinemia
at weaning. Furthermore, the increased biomechanical loading due to increased body
weight probably help us to understand the protective effects obesity exerts upon bone
health.
Key words
early overfeeding - bone - programming
