Accelerated growth without prepubertal obesity in nutritionally programmed microswine offspring

Poor fetal growth and associated prepubertal growth acceleration are linked to increased risk of cardiometabolic dysfunction in later life, but whether obesity is integral to catch-up growth and its ensuing risks are unknown. In microswine offspring exposed to perinatal maternal protein restriction (MPR), we measured body and organ sizes (during MPR); linear growth and weight gain (birth to 5 months of age); feed intake and utilization efficiency (5-14 weeks); and body composition at 6 and 11 weeks of age (by dual-energy X-ray absorptiometry, DEXA). During MPR, low protein offspring (LPO) showed asymmetric growth restriction with reduced body weight (Wt):length (Lth) at birth and elevated heart Wt:liver Wt ratio by 2 weeks of age. In LPO, after slow early postnatal growth (0-5 weeks), subsequent linear growth on ad libitum normal feed was absolutely accelerated (cm/week; P < 0.001) over 6-11 weeks but normal thereafter, whereas absolute weight gain (kg/week) was similar to controls but accelerated relative to lower LPO nadir weights. Concurrently, rates of fat and lean tissue accrual in LPO over 6-11 weeks were similar to normal protein offspring in absolute terms (g/5 weeks) but increased relative to lower mass at 6 weeks, yielding normal lean:Lth but reduced fat:Lth ratios at 11 weeks. LPO had higher relative feed intake (g/kg/meal) in both sexes and higher feed efficiency in females over 5-11 weeks of age. Findings suggest that postnatal linear growth acceleration preserved thinness in juvenile LPO. Given separately reported abnormalities of vascular (Bagby et al., 2011) and adipocyte function in juvenile LPO, (DuPriest et al., 2011) findings demonstrate that perinatal MPR programs catch-up growth and cardiovascular abnormalities independently of obesity.