[Fetal growth retardation and postnatal high fat diet on the development of insulin resistance and fertility: experiment with rats].

OBJECTIVE: To investigate the influences of fetal growth retardation (FGR) and postnatal high fat diet (HF) on the development of insulin resistance (IR), puberty development and fertility problems in female rat offspring.

METHODS: FGR model was induced by maternal low protein diet. 32 newborn FGR rats and 32 control rats were randomly divided into two equal groups: FGR/HF group (with the mother rats given with high fat diet for 3 weeks after delivery), FGR/N (with the mother rats given with normal diet), C/HF group (control newborn rat group with the mother rats given with high fat diet), and C/N group (control newborn rat group with the mother rats given with normal diet). The pups were fed by mother milk. All pups were weaned at the 4th week of age and then fed with the diet the same diet as that during the lactation period until the end of experiment. From day 30 onwards, vaginal opening and oestrous cycle were inspected daily on 10 pups in each group. At the 13th week, body weight, length and perirenal fat weight/body weight (Fw/Bw) were recorded for 10 pups in each group. At the same time, fasting plasma glucose (FPG), fasting insulin (FINS), and testosterone level were measured. From the 13th week onwards, mating test was performed for 6 pups in each group.

RESULT: At the 13th week, there was an obesity tendency in the FGR/N, FGR/HF and C/HF groups. The FINS levels were all higher, and insulin sensitivity index (ISI) levels were all significantly lower in these three groups than in the C/N group (all P < 0.05). The homeostasis model assessment insulin resistance index (HOMA-IR) levels of the FGR/N and FGR/HF groups were significantly higher than that of the C/N group (both P < 0.05), the FINS and HOMA-IR of the FGR/HF group were significantly higher than that of the FGR/N group (both P < 0.05). There was oligoovulation in the FGR and high fat diet rats, the pregnancy rate of the FGR/HF group was significantly lower than that of the C/N group (P < 0.05). FGR/HF group had the most serious obesity, IR and fertility problems.

CONCLUSION: There are puberty disturbance, oligoovulation and IR in FGR and high fat diet rats. IR, puberty development and fertility problems are linked and occur independently of the postnatal nutrition, but can be exacerbated by postnatal high fat diet.