Improvement of leptin and insulin sensitivity due to early nutritional intervention in rats born with intrauterine growth retardation / 中华内分泌代谢杂志

ABSTRACT

Objective To look for an appropriate dietary pattern of early nutritional intervention, which does not only meet the need of catch-up growth but also avoids or reduces the incidence of insulin resistance (IR) in adulthood of rats born with intrauterine growth retardation (IUGR). Methods The model of IUGR in rats was established by maternal nutrition restriction. Sixty newborn female rats with IUGR were randomly divided into 5 groups: (1) IUGR control group fed with common diet. (2) IUGR high-carbohydrate diet group. (3) IUGR high-fat diet group. (4) IUGR high-protein diet group. (5) IUGR low-protein diet group. The IUGR newborn rats were breast-fed for 3 weeks, while the mother rats were fed with the above different diets with the same caloric amount. Twelve normal newborn female rats served as a normal control group and were fed with common diet. All newborn rats were fed routine diet starting from the 4th week of experiment. The body weight, perirenal fat weight and the serum leptin, blood glucose, insulin concentration were measured and the insulin sensitive index (ISI) were calculated at the 4th week and the 12th week of life. Results The IUGR rats fed with high-protein diet showed a catch-up growth without the increase of perirenal fat at the 4th week, a normal level of perirenal fat, leptin and ISI at the 12th week compared with the normal control group, and did not show IR. The groups fed with high carbohydrate diet and high fat diet also showed a catch-up growth, but did the same as the IUGR control group in other aspects, they all showed increased perirenal fat, higher levels of leptin, lower ISI and IR at adulthood. The group fed with low protein diet did not show IR, but kept a small body size with increased perirenal fats. The serum leptin level of rats was positively correlated to body weight at the 4th week of life and was positively correlated to the weight of perirenal fat and negatively correlated to ISI at the 12th week of life. Conclusion High protein diet is an appropriate early nutritional intervention for rats with IUGR. The serum leptin level at the 12th week of life seems to be an index of IR in adult rats with IUGR.