[Long-term effects of mild hyperglycemia exposure in utero and postnatal high fat diet on body weight and lipid metabolism in rat offsprings].

OBJECTIVE: To investigate the long-term effects of intrauterine mild hyperglycemia exposure and postnatal high fat diet on the body weight and metabolism of offspring through a pregnant rat model of intrauterine mild hyperglycemia.

METHODS: Twenty-one pregnant Wistar rats were randomly divided into intrauterine hyperglycemia group and control group. Twenty percent streptozotocin (STZ, 25 mg/kg)was given to rats of intrauterine hyperglycemia group by a single intraperitoneal injection to induce intrauterine mild hyperglycemia; control group rats received an equal volume of citric acid-sodium citrate buffer. Off springs were divided into 4 groups: exposed to intrauterine hyperglycemia and fed with normal diet group (group DN) or high fat diet group (group DF); exposed to intrauterine euglycemia and fed with normal diet group (group CN) or high fat diet group (group CF). The blood glucose levels of pregnant rats in two groups and body weights of offsprings in four groups were recorded. At the age of 28 weeks, the mesenteric fat amount, epididymal amount, perirenal fat amount, total triglyceride (TG) and high density 1ipoprotein-cholestrol (HDL-C) were measured in all four groups.

RESULTS: (1)The average blood glucose level of intrauterine hyperglycemia group [(16.6 ± 3.4) mmol/L] was significantly higher than that of the control group [(5.8 ± 1.1) mmol/L, P < 0.01]. (2) On the birth day, 3 weeks and 4 weeks, the body weight of group DN[(7.4 ± 0.6), (44.1 ± 5.9), (79.6 ± 7.4) g] and group DF [(7.4 ± 0.2), (43.9 ± 6.9), (76.1 ± 5.8) g] were remarkably increased compared with group CN [(6.6 ± 0.5),(35.6 ± 4.4),(71.5 ± 6.8) g, P < 0.05]; but the body weight in group CF [(6.7 ± 0.5),(33.0 ± 6.5),(66.1 ± 10.2) g] had no statistical difference compared with group CN (P > 0.05). (3)From then on, the body weights of the offsprings in four groups presented an increasing trend, but there was no statistical difference until 28 weeks (P > 0.05). (4) The perirenal fat amount of group DN, group CF and group DF [(13.8 ± 3.3), (14.3 ± 3.2), (18.4 ± 1.3) g] were remarkably increased compared with group CN[(9.7 ± 3.5) g, P < 0.05]; the epididymal fat amount of group CF and group DF were also significantly increased compared to group CN (P < 0.05); the mesenteric fat amount in four groups had no statistical difference (P > 0.05). (5) The TG level of group DN, group CF and group DF [(0.52 ± 0.14), (0.52 ± 0.09), (0.54 ± 0.17) mmol/L] were significantly higher compared to group CN [(0.41 ± 0.09) mmol/L, P < 0.05], but there was no statistical difference within the first three groups (P > 0.05); the HDL-C level in four groups had no statistical difference (P > 0.05).

CONCLUSIONS: In intrauterine mild hyperglycemia environment, there were some evidently metabolic changes observed in the offspring, including body weight increasing on birth day and early postnatal period, visceral fat amount increasing and lipid metabolism disorders, which could be aggravated by postnatal high fat diet.