Study Of The Relationship Between Dietary Nutrients Intake Before And During Pregnancy And Gestational Diabetes Mellitus

Objective:1.To examine the relationship between dietary energy,protein,fat,carbohydrate,fiber,and cholesterol intake before and during pregnancy and risk of gestational diabetes mellitus(GDM).2.To investigate the influence of different dietary nutrients intake on gestational diabetes mellitus with different pre-pregnancy BMI during the previous year before conception,the first,and second trimester of pregnancy.Methods:A total of 10,320 pregnant women were recruited in Taiyuan birth cohort study in 2012-2016.After exclusion of 1,137 pregnant women who did not meet the inclusion criteria,9,183 were analyzes for the current project.There were 1,400 pergnanct women being diagnosed as GDM and 7,783 without GDM(non-GDM group).A standardized and structured questionnaire was adopted to collect information on demographic characteristics,lifestyle factors,medical history,perinatal care,and occupational history.Dietary intake was assessed using a 33-item food frequency questionnaire(FFQ).Participants were asked to report the frequency and consumption of standard portion size each time for each food during the previous year before conception,the first,and second trimester of pregnancy.The response of participants were converted to food intake in grams per day for analysis.EpiData3.1 software was used for data entry and SAS 9.4 was used for data analysis.A chisquared test was conducted to compare the difference of each characteristic between cases and controls.Multivariate unconditioned logistic regression model was used to estimate odds ratios(OR)and 95% confidence intervals(CI).P<0.05 was considered as statistical significance and analyses were two-sided.Results:1.General informationThe maternal age ranged from 18 to 59 years old with the mean age of 29.07(±4.58)years.Approximately half the women's education level was undergraduate or above(47.28%,4336/9170),followed by high school level(35.31%,3238/9170).Majority of families' income was in mid level(59.09%,5182/8769).2.The risk factors of gestational diabetes mellitusThe univariate analysis showed that the maternal age,education level,family income,location of residence,parity,family history of diabetes,family history of hypertension,hypertensive disorder during pregnancy,pre-pregnancy BMI,weight gain during pregnancy,pre-pregnancy or pregnancy supplemental folic acid were associated with GDM.The intake of total fatty acids,saturated fatty acids,monounsaturated fatty acids,polyunsaturated fatty acids,carbohydrates,dietary fiber,soluble dietary fiber,and insoluble dietary fiber were also associated with GDM risk(P <0.05).3.Multivariate analysis of GDM factors3.1 The influence of dietary energy intake on GDMCompared to the first quartile(Q1)of dietary energy intake one year before pregnancy,the forth quartile(Q4,? 1547.77 Kcal/d))energy intake one year before pregnancy was associated with increased risk of GDM(OR=1.221,95%CI: 1.027 ~ 1.452).After stratified by pre-pregnancy BMI,the Q4 energy intake during one year before pregnancy and the first trimester was associated with increased risk of GDM(OR=2.217,95%CI:1.207~4.074;OR=1.295,95%CI:1.034~1.622 respectively)among women who had pre-pergnancy BMI overweight/obese.3.2 The influence of dietary protein intake on GDMNo statistically significant associations were found between dietary protein intake during one year before pregnancy,the first and the second trimester and GDM.Prepregnancy BMI did not modify the assocaition.3.3 The influence of dietary fat intake on GDMCompared to the Q1 dietary fat intake one year before pregnancy,the Q4(?47.67 g/d)fat intake was associated with increased risk of GDM(OR=1.197,95%CI: 1.002 ~1.431).Further analysis showed that dietary total fatty acids,saturated fatty acids,monounsaturated fatty acids,and polyunsaturated fatty acid intakes were all related to GDM in different stages of pregnant women.After stratified by pre-pregnancy BMI,women with normal pre-pregnancy BMI had an increased risk of GDM(OR=1.281,95% CI: 1.020~1.610)associated with dietary fat intake in Q4 level(? 47.67g/d)one year before pregnancy.Among women with pre-pregnancy BMI overweight/obese,Q3 and Q4 dietary fat intake one year before pregnancy and Q4 dietary fact intake during the second trimester were associated with increased risk of GDM(OR=1.938,95%CI:1.035~3.630;OR=1.787,95%CI:1.021~3.128;OR=1.276,95%CI:1.015~1.602,respectively).Further analysis found that dietary total fatty acids,saturated fatty acids,monounsaturated fatty acids,and polyunsaturated fatty acid intakes of pregnant women with different pre-pregnancy BMI were related to GDM at different stages.3.4 The influence of dietary carbohydrate intake on GDMThe Q4 dietary carbohydrate intake one year before pregnancy,during the first trimester and the second trimester were associated with increased risk of GDM(OR=1.252,95%CI:1.056~1.485;OR=1.199,95%CI:1.011~1.421;and OR=1.306,95%CI:1.098~1.554,respectively).After stratification by pre-pregnancy BMI,Q3 and Q4 carbohydrate intake one year before pregnancy and Q4 carbohydrate intak during the first trimester in the normal pre-pregnancy BMI group were associated with increased risk of GDM(OR=1.382,95%CI:1.111~1.719;OR=1.264,95%CI : 1.017~1.571;OR=1.299,95%CI : 1.044~1.616,respectively).The Q4 carbohydrate intak during the second trimester was also associated with increased risk of GSM among pre-pregnancy BMI overweight/obese group(OR=1.335,95%CI:1.069~1.668).3.5 The influence of dietary fiber intake on GDMNo statistically significant association was found between dietary fiber,soluble dietary fiber,insoluble dietary fiber intake one year before pregnancy or during the first or second trimester and GDM risk in overall population or by pre-pregnancy BMI.3.6 The influence of dietary cholesterol intake on GDMThe Q4(?76.49 mg/d)dietary cholesterol intake one year before pregnancy was associated with increased risk of GDM(OR=1.371,95%CI: 1.105~1.700)and the observed assocaition was mainly seen among women who had pre-pregnancy BMI overweight/obese.The Q4 dietary cholesterol intake(? 76.49 mg/d)during the second trimester was also associated with risk of GDM(OR=1.205,95% CI: 1.010~1.439).Conclusions:1.High level of dietary energy intake one year before pregnancy was asosiated with increased risk of GDM,and the increased risk varied by pre-pregnancy BMI.2.High levels of dietary fat intake one year before pregnancy was associated with increased risk of GDM,and the risk varied by pre-pregnancy BMI3.High level of dietary carbohydrate intake one year before pregnancy and during the first and second trimester was associated with increased risk of GDM,and the risk varied by pre-pregnancy BMI.4.High intake of dietary cholesterol one year before pregnancy and during the second trimester was associated with increased risk of GDM and the risk varied by pre-pregnancy BMI.While the study results warrant replication in different study populations,the study results suggest a potential interventional opportunity for reducing GDM by controlling for dietary energy and macronutrient intake.