Exercise in pregnant rats born smallattenuates bone deficits without negative effects of
high-fat diet
Anevska K1,2, Mahizir D2, Briffa JF2, Jefferies AJ2, Wark JD2,3, Wlodek ME2 and Romano T1
1La Trobe University, Melbourne, Australia
2The University of Melbourne, Parkville, Australia
3Royal Melbourne Hospital, Parkville, Australia
Low birth weight is known toprogram poor adult bone healthand increasesobesityrisk, whichcan alter bone metabolism.Pregnancy and obesity in females born smallcan exacerbate pre-existing bone deficits. Exercising prior to pregnancy can reverse negative effects of obesity potentially influencing bone health.We aimed to determine whether high-fat diet (HFD) consumption would exacerbate bone deficits during pregnancy in females born small and whetherendurance exercise prior to and during pregnancy would attenuate these deficits.
Uteroplacental insufficiencywas induced on embryonic day 18 (E18) in WKY rats using bilateral uterine vessel ligation (Restricted) or sham (Control) surgery (F0 generation). F1 females consumed standard chow or HFD (23% fat) from age 5 weeks, ad libitum,and were mated at 20 weeks. Femalerats exercised on a treadmill for 4 weeks prior to and during pregnancy or remained sedentary. Femora and plasmawere collected at post-mortem (E20) for pQCT and bone marker analysis.
SedentaryRestricted females had decreased trabecular and cortical content, cortical thickness, periosteal and endosteal circumferences and bending strength (p<0.05), irrespective of diet compared to Controls. HFD increased trabecular density in Control and Restricted Sedentary females. Interestingly, exercise before and during pregnancy prevented these bonedeficits. Plasma osteocalcin concentrationswere increased in Sedentary Restricted females (p<0.05). HFD reducedosteocalcin and increased CTX-1 concentrations in Sedentary females(p<0.05).Bone turnover markers were not different in pregnant chow and HFD females with exercise intervention.
HFD did not exacerbate bone deficits in Restricted females.However changes detected in bone markers in Sedentary HFD femaleshighlights the possibility of altered bone metabolism. Bone deficits in females born small during late gestation were prevented by exercise intervention; highlighting exercise as a therapy for females born small who are at risk of developing bone deficits.