Effects of gestational malnutrition on glucose and lipid metabolism of pregnant rats and birth weight of their offsprings / 中华围产医学杂志

ABSTRACT

Objective To explore the glucose and liplid metabolism changes of pregnant rats and the birth weight of their offsprings due to pregnancy malnutrition,including overnutrition and undernutrition.Methods Thirty pregnant Wistar rats were randomly divided into three groups on the day of conception,the high-fat-diet group,normal control group and 50％ food-restricted diet group.Increase of body weight and serum level of triglycerides,high-density lipoprotein,low-density lipoprotein,oral glucose tolerance test (OGTT) and insulin release test(IRT) levels during pregnancy were measured.The birth weight of offsprings was recorded within 12 h after birth.One-way ANOVA,LSD or Dunnett T3,and Chi-square test were applied for statistical analysis.Results The body weight at late pregnancy and the level of triglycerides and low-density lipoprotein were significantly increased in the high-fat-diet rats compared to normal control ones [(1.68±0.13) mmol/L vs (0.78±0.08) mmol/L,(0.57±0.04) mmol/L vs (0.35±0.07) mmol/L; both P＜0.01].While the level of high-density lipoprotein of high-fat-diet rats was lower than that of the normal control rats [(0.56±0.06) mmol/L vs (1.09±0.08) mmol/L,P＜0.05].The level of triglycerides,low density lipoprotein and high density lipoprotein in 50％ food restricted group [(0.47±0.06) mmol/L,(0.21±0.06) mmol/L and (0.42±0.05) mmol/L] were lower than the control group (all P＜0.05).Impaired glucose tolerance,abnormal OGTT and IRT results were found in both high-fat-diet and 50％ foodrestricted diet rats.The fasting plasma glucose level in high-fat-diet group was significantly increased in late pregnancy compared to the control [(6.63±0.53) mmol/L vs (4.90±0.26) mmol/L,P＜0.05],while there was no significant difference between rats in 50％ food-restricted diet [(4.18±0.26) mmol/L]and control group (P＞0.05).There was no statistical difference in fasting serum insulin level among the three groups.The average birth weight was significantly increased in high-fat-diet rats than in the control group [(6.14±0.31) g vs (5.73±0.26) g,P＜0.05],and the incidence of macrosomic newborn rats in the high-fat-diet group was also higher than that of the control group [19.2 ％ (19/99)vs 7.84％(8/102),P＜0.05].The birth weight of offspring in 50％ food-restricted diet group was decreased with their average birth weight of (4.54±0.23) g,which was lower than that of the control group (P＜0.05).The incidence of macrosomic [13.40％ (11/76)] and low birth weight newborn rats [15.90％ (13/76) vs 3.92％(4/102)] in food-restricted diet group were both higher than in the control group (P＜0.05); and smaller number of offsprings was obtained than the control group (76 vs 102,P＜0.05),the number of offsprings in high-fat-diet group was 99,which was less than the control group without statistical difference (P＞0.05).Conclusions Pregnancy malnutrition,including overnutrition and undernutrition,may affect the lipid metabolism and glucose tolerance of pregnant rats,leading to insulin resistance,and may also contribute to the abnormal birth weight of the offspring,including macrosomia and low birth weight.