Heterogeneity of maternal characteristics and impact on gestational diabetes (GDM) risk-Implications for universal GDM screening?

Genetic risk of type 2 diabetes modifies the association between lifestyle and glycemic health at 5 years postpartum among high-risk women

INTRODUCTION

Lifestyle interventions are effective in preventing type 2 diabetes, but genetic background may influence the individual response. In the Finnish gestational diabetes prevention study, RADIEL, lifestyle intervention during pregnancy and first postpartum year was effective in preventing gestational diabetes (GDM) and postpartum glycemic abnormalities only among women at highest genetic risk of type 2 diabetes. This study aimed to assess whether still 5 years postpartum the genetic risk modifies the association between lifestyle and glycemic health.

RESEARCH DESIGN AND METHODS

The RADIEL study (randomized controlled trial) aimed to prevent GDM with a lifestyle intervention among high-risk women (body mass index ≥30 kg/m2 and/or prior GDM). The follow-up study 5 years postpartum included anthropometric measurements, laboratory assessments, device-measured physical activity (PA), and questionnaires. A Healthy Lifestyle Score (HLS) indicated adherence to lifestyle goals (PA, diet, smoking) and a polygenic risk score (PRS) based on 50 type 2 diabetes risk alleles depicted the genetic risk.

RESULTS

Altogether 314 women provided genetic and glycemic data 5 years postpartum. The PRS for type 2 diabetes was not associated with glycemic abnormalities, nor was HLS in the total study sample. There was, however, an interaction between HLS and type 2 diabetes PRS on glycemic abnormalities (p=0.03). When assessing the association between HLS and glycemic abnormalities in PRS tertiles, HLS was associated with reduced risk of glycemic abnormalities only among women at the highest genetic risk (p=0.008).

CONCLUSIONS

These results extend our previous findings from pregnancy and first postpartum year demonstrating that still at 5 years postpartum, healthy lifestyle is associated with a lower risk of prediabetes/diabetes only among women at the highest genetic risk of type 2 diabetes.

Gestational diabetes mellitus: genetic factors, epigenetic alterations, and microbial composition

Gestational diabetes mellitus (GDM) is a common metabolic disorder, usually diagnosed during the third trimester of pregnancy that usually disappears after delivery. In GDM, the excess of glucose, fatty acids, and amino acids results in foetuses large for gestational age. Hyperglycaemia and insulin resistance accelerate the metabolism, raising the oxygen demand, and creating chronic hypoxia and inflammation. Women who experienced GDM and their offspring are at risk of developing type-2 diabetes, obesity, and other metabolic or cardiovascular conditions later in life. Genetic factors may predispose the development of GDM; however, they do not account for all GDM cases; lifestyle and diet also play important roles in GDM development by modulating epigenetic signatures and the body's microbial composition; therefore, this is a condition with a complex, multifactorial aetiology. In this context, we revised published reports describing GDM-associated single-nucleotide polymorphisms (SNPs), DNA methylation and microRNA expression in different tissues (such as placenta, umbilical cord, adipose tissue, and peripheral blood), and microbial composition in the gut, oral cavity, and vagina from pregnant women with GDM, as well as the bacterial composition of the offspring. Altogether, these reports indicate that a number of SNPs are associated to GDM phenotypes and may predispose the development of the disease. However, extrinsic factors (lifestyle, nutrition) modulate, through epigenetic mechanisms, the risk of developing the disease, and some association exists between the microbial composition with GDM in an organ-specific manner. Genes, epigenetic signatures, and microbiota could be transferred to the offspring, increasing the possibility of developing chronic degenerative conditions through postnatal life.

Mouse Models of Gestational Diabetes Mellitus and Its Subtypes: Recent Insights and Pitfalls

Gestational diabetes mellitus (GDM) is currently the most common complication of pregnancy and is defined as a glucose intolerance disorder with recognition during pregnancy. GDM is considered a uniform group of patients in conventional guidelines. In recent years, evidence of the disease's heterogeneity has led to a growing understanding of the value of dividing patients into different subpopulations. Furthermore, in view of the increasing incidence of hyperglycemia outside pregnancy, it is likely that many cases diagnosed as GDM are in fact patients with undiagnosed pre-pregnancy impaired glucose tolerance (IGT). Experimental models contribute significantly to the understanding of the pathogenesis of GDM and numerous animal models have been described in the literature. The aim of this review is to provide an overview of the existing mouse models of GDM, in particular those that have been obtained by genetic manipulation. However, these commonly used models have certain limitations in the study of the pathogenesis of GDM and cannot fully describe the heterogeneous spectrum of this polygenic disease. The polygenic New Zealand obese (NZO) mouse is introduced as a recently emerged model of a subpopulation of GDM. Although this strain lacks conventional GDM, it exhibits prediabetes and an IGT both preconceptionally and during gestation. In addition, it should be emphasized that the choice of an appropriate control strain is of great importance in metabolic studies. The commonly used control strain C57BL/6N, which exhibits IGT during gestation, is discussed in this review as a potential model of GDM.

Ascending Growth is Associated with Offspring Adiposity in Pregnancies Complicated with Obesity or Gestational Diabetes

CONTEXT

Early growth is associated with childhood adiposity, but the influence of lifestyle remains unknown.

OBJECTIVE

This work aimed to investigate the association of growth profiles from high-risk pregnancies with adiposity at age 5 years, taking into account lifestyle and several antenatal/postnatal exposures.

METHODS

This prospective cohort study.

INCLUDED

609 children born during the Finnish Gestational Diabetes Prevention Study (RADIEL), recruiting women with body mass index (BMI) greater than or equal to 30 and/or prior gestational diabetes mellitus (GDM) (2008-2013). Altogether 332 children attended the 5-year follow-up (2014-2017). Main outcome measures included growth profiles based on ponderal index (PI = weight/height3), investigated using latent class mixed models. Adiposity was assessed with anthropometrics and body composition (InBody720).

RESULTS

We identified 3 growth profiles: ascending (n = 82), intermediate (n = 351), and descending (n = 149). Children with ascending growth had a higher body fat percentage, ISO-BMI, and waist circumference (P < .05) at age 5 years. Ascending (β 4.09; CI, 1.60-6.58) and intermediate (β 2.27; CI, 0.50-4.03) profiles were associated with higher fat percentage, even after adjustment for age, sex, gestational age, diet, physical activity, education, and prepregnancy BMI. Similar associations existed with ISO-BMI. After adjusting for age and education, ascending growth was associated with prepregnancy BMI (odds ratio [OR] 1.06; CI, 1.01-1.12), primiparity (OR 3.07; CI, 1.68-5.62), cesarean delivery (OR 2.23; CI, 1.18-4.21), and lifestyle intervention (OR 2.56; CI, 1.44-4.57). However, meeting the intervention goals and exclusive breastfeeding for 3 months or more were associated with lower odds of ascending growth.

CONCLUSION

Accelerated early growth was associated with higher adiposity in 5-year-old children from high-risk pregnancies, even when adjusted for lifestyle. Reducing cesarean deliveries and promoting breastfeeding may be beneficial for postnatal growth.

Contribution of gestational diabetes mellitus heterogeneity and prepregnancy body mass index to large-for-gestational-age infants-A retrospective case-control study

OBJECTIVE

To study the associations between heterogeneity of gestational diabetes mellitus (GDM) subtype/prepregnancy body mass index (pre-BMI) and large-for-gestational-age (LGA) infants of Chinese women.

METHODS

We performed a retrospective case-control study of 299 women with GDM and 204 women with normal glucose tolerance (NGT), using oral glucose tolerance test-based indices performed at 24-25 weeks of gestation. Women with GDM were classified into the following three physiologic subtypes: GDM with a predominant insulin-secretion defect (GDM-dysfunction), GDM with a predominant insulin-sensitivity defect (GDM-resistance), or GDM with both defects (GDM-mixed). We then used a binary logistic regression model to evaluate the potential associations of GDM subtypes and pre-BMI with newborn macrosomia or LGA.

RESULTS

Women with GDM-resistance had a higher pre-BMI (P < 0.001), whereas women in the GDM-dysfunction and GDM-mixed groups had pre-BMIs comparable to the NGT group. In the logistic regression model, women in the GDM-mixed group exhibited an increased risk of bearing newborns with macrosomia and LGA, and women in the GDM-dysfunction group tended to have newborns with LGA after adjusting for pre-BMI and other potential confounders. Women who were overweight or obese prepregnancy manifested an increased risk of having newborns with macrosomia and LGA relative to normal-weight women, regardless of whether values were unadjusted or adjusted for all potential confounders. There was no significant interaction between GDM subtype and pre-BMI for any of the studied outcomes.

CONCLUSIONS

Heterogeneity of GDM (GDM-dysfunction and GDM-mixed) and prepregnancy overweight/obesity were independently associated with LGA in Chinese women. There was no significant interaction between GDM subtypes and pre-BMI for LGA.

Risk Factors Screening for Gestational Diabetes Mellitus Heterogeneity in Chinese Pregnant Women: A Case-Control Study

PURPOSE

To study the risk factors of gestational diabetes mellitus (GDM) heterogeneity, and to evaluate the correlation between the risk factors and obesity.

METHODS

We performed a case-control study of 452 women with GDM and 516 women with normal glucose tolerance (NGT) at the first and second trimester. We defined GDM women as GDM-resistance subtype, GDM-dysfunction subtype, and GDM-mixed subtype, according to their simultaneous insulin-release test with predominant insulin-sensitivity defect, insulin-secretion defect, or both defects.

RESULTS

We found that higher maternal age, family history of diabetes, the elevated level of fasting blood glucose in the first trimester (≥5.1 mmol/L) were risk factors of all GDM subtypes. Pre-pregnancy overweight/obesity and the increased gestational weight gain (GWG) in the first-trimester are risk factors of the GDM-resistance subtype. Indicators including younger age at first menstruation, the elevated levels of alanine aminotransferase (ALT), total bile acid (TBA), triglyceride (TG), and the decreased level of high-density lipoprotein cholesterol (HDL-C) are risk factors of the GDM-resistance subtype. However, the associations between those risk factors and GDM-resistance subtype attenuated after adjusted by pre-pregnancy body mass index (pre-BMI) and gestational weight gain (GWG) in the first trimester. Nonalcoholic fatty liver disease (NAFLD) and the improved level of TG are independent risk factors for the GDM-resistance subtype and the GDM-mixed subtype, respectively.

CONCLUSION

Women with GDM exhibited heterogeneity based on glycemic physiology and their risk factors are not all the same. Some obesity-related risk factors are specific to the GDM-resistance subtype, which are mediated by pre-pregnancy overweight/obesity and the elevated GWG the first-trimester.

Lifestyle and glycemic health 5 years postpartum in obese and non-obese high diabetes risk women

AIM

Women with prior gestational diabetes (GDM) are at increased diabetes risk. This study aimed to assess whether lifestyle is associated with glycemic health of high-risk women 5 years postpartum, taking into account the pre-pregnancy BMI.

METHODS

The RADIEL study enrolled before or in early pregnancy 720 women with pre-pregnancy BMI ≥ 30 kg/m² and/or prior GDM. The follow-up visit 5 years postpartum included questionnaires and measurements of anthropometrics, blood pressure, and physical activity (PA) as well as analyses of glucose metabolism, lipids, and inflammatory markers. We measured body composition (Inbody) and calculated a Healthy Food Intake Index (HFII) from Food Frequency Questionnaires (FFQ). ArmBand measured PA, sedentary time, and sleep. To take into account the diverse risk groups of GDM, we divided the women based on pre-pregnancy BMI over/under 30 kg/m².

RESULTS

Altogether 348 women attended the follow-up. The obese and non-obese women showed similar prevalence of glycemic abnormalities, 13% and 19% (p = 0.139). PA levels were higher among the non-obese women (p < 0.05), except for step count, and their HFII was higher compared to the obese women (p = 0.033). After adjusting for age, education, and GDM history, PA and HFII were associated with glycemic health only among obese women. When both lifestyle factors were in the same model, only PA remained significant. PA associated with other markers of metabolic health also among the non-obese women, excluding HbA1c.

CONCLUSION

Lifestyle 5 years postpartum was associated with better glycemic health only among the obese high-risk women. PA, however, is essential for the metabolic health of all high-risk women.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, http://www.clinicaltrials.com , NCT01698385.

Neonatal outcomes among offspring of obese women diagnosed with gestational diabetes mellitus in early versus late pregnancy

BACKGROUND

Maternal metabolic derangements associated with early pregnancy gestational diabetes may affect the fetus differently compared with gestational diabetes diagnosed later in pregnancy. The aim of this observational study was to assess neonatal outcomes according to timing of gestational diabetes diagnosis in obese women.

METHODS

Women ≥18 years of age with a pre-pregnancy body mass index ≥30 kg/m2 were grouped according to the results of a 75 g 2-h oral glucose tolerance test performed at 13.1 weeks of gestation and repeated at 23.4 weeks if normal at first testing. The main outcomes were birthweight and large for gestational age.

RESULTS

Out of 361 women, 164 (45.4%) were diagnosed with gestational diabetes, 133 (81.1%) of them in early pregnancy. The mean offspring birthweight was 3673 g (standard deviation (SD) 589 g) in the early and 3710 g (SD 552 g) in the late gestational diabetes group. In a multivariate logit model, the odds ratio for large for gestational age was 2.01 (95% CI: 0.39-10.39) in early compared with late gestational diabetes.

CONCLUSIONS

We observed no statistically significant differences in neonatal outcomes according to timing of gestational diabetes diagnosis. In addition to lack of power, early treatment of hyperglycemia may partly explain the results.

Effect of maternal lifestyle intervention on metabolic health and adiposity of offspring: Findings from the Finnish Gestational Diabetes Prevention Study (RADIEL)

AIM

To assess in women at high risk of gestational diabetes mellitus (GDM) the effect of a lifestyle intervention on the metabolic health of their offspring around 5 years after delivery.

METHODS

For the original Finnish gestational diabetes prevention study (RADIEL), 720 women with a prepregnancy body mass index (BMI)≥30kg/m² and/or previous GDM were enrolled before or during early pregnancy and allocated to either an interventional (n=126) or conventional (n=133) care group. The present 5-year follow-up substudy assessed the metabolic health outcomes of their offspring. Age- and gender-standardized residuals of metabolic health components (waist circumference, mean arterial pressure, high-density lipoprotein and triglyceride levels, and fasting insulin/glucose ratio) were also combined to determine the accumulation of metabolic effects. Body composition was assessed by electrical bioimpedance.

RESULTS

Offspring of women in the intervention group had a less optimal metabolic profile after the 5-year follow-up compared with offspring in the usual care group (P=0.014). This difference in metabolic health was primarily related to lipid metabolism, and was more prominent among boys (P=0.001) than girls (P=0.74). Neither GDM, gestational weight gain, prepregnancy BMI, offspring age nor timing of randomization (before or during pregnancy) could explain the detected difference, which was also more pronounced among the offspring of GDM pregnancies (P=0.010). Offspring body composition was similar in both groups (P>0.05).

CONCLUSION

The lifestyle intervention aimed at GDM prevention was associated with unfavourable metabolic outcomes among offspring at around 5 years of age.

Precision medicine in type 2 diabetes

The Precision Medicine Initiative defines precision medicine as 'an emerging approach for disease treatment and prevention that takes into account individual variability in genes, environment and lifestyle for each person'. This approach will facilitate more accurate treatment and prevention strategies in contrast to a one-size-fits-all approach, in which disease treatment and prevention strategies are developed for generalized usage. Diabetes is clearly more heterogeneous than the conventional subclassification into type 1 and type 2 diabetes. Monogenic forms of diabetes like MODY and neonatal diabetes have paved the way for precision medicine in diabetes, as carriers of unique mutations require unique treatment. Diagnosis of diabetes in the past has been dependent upon measuring one metabolite, glucose. By instead including six variables in a clustering analysis, we could break down diabetes into five distinct subgroups, with better prediction of disease progression and outcome. The severe insulin-resistant diabetes (SIRD) cluster showed the highest risk of kidney disease and highest prevalence of nonalcoholic fatty liver disease, whereas patients in the insulin-deficient cluster 2 (SIDD) had the highest risk of retinopathy. In the future, this will certainly be improved and expanded by including genetic, epigenetic and other biomarker to allow better prediction of outcome and choice of more precise treatment.

Heterogeneity of gestational diabetes (GDM) and challenges in developing a GDM risk score

AIMS

Gestational diabetes (GDM) affects a growing number of women and identification of individuals at risk, e.g., with risk prediction models, would be important. However, the performance of GDM risk scores has not been optimal. Here, we assess the impact of GDM heterogeneity on the performance of two top-rated GDM risk scores.

METHODS

This is a substudy of the RADIEL trial-a lifestyle intervention study including women at high GDM risk. We assessed the GDM risk score by Teede and that developed by Van Leeuwen in our high-risk cohort of 510 women. To investigate the heterogeneity of GDM, we further divided the women according to GDM history, BMI, and parity. With the goal of identifying novel predictors of GDM, we further analyzed 319 women with normal glucose tolerance in the first trimester.

RESULTS

Both risk scores underestimated GDM incidence in our high-risk cohort. Among women with a BMI ≥ 30 kg/m² and/or previous GDM, 49.4% developed GDM and 37.4% received the diagnosis already in the first trimester. Van Leeuwen score estimated a 19% probability of GDM and Teede succeeded in risk identification in 61%. The lowest performance of the risk scores was seen among the non-obese women. Fasting plasma glucose, HbA_1c, and family history of diabetes were predictors of GDM in the total study population. Analysis of subgroups did not provide any further information.

CONCLUSIONS

Our findings suggest that the marked heterogeneity of GDM challenges the development of risk scores for detection of GDM.

Prevention of gestational diabetes with a prepregnancy lifestyle intervention - findings from a randomized controlled trial

Purpose

Lifestyle intervention studies performed during pregnancy have shown inconsistent results in relation to prevention of gestational diabetes mellitus (GDM). Therefore, the aim of this study was to assess the effect of an intervention initiated already before pregnancy in prevention of GDM in high-risk women.

Patients and methods

A randomized controlled trial was conducted in four Finnish maternity hospitals between the years 2008 and 2014. Altogether 228 high-risk women planning pregnancy were randomized to an intervention (n=116) or a control group (n=112). The risk factors were body mass index ≥30 kg/m² (n=46), prior GDM (n=120), or both (n=62), without manifest diabetes at study inclusion. Trained study nurses provided individualized lifestyle counseling every 3 months in addition to a group session with a dietician. The control group received standard antenatal care. GDM was defined as one or more pathological glucose values in a 75 g 2-hour oral glucose tolerance test, performed between 12 and 16 weeks of gestation and if normal repeated between 24 and 28 weeks of gestation.

Results

Within 12 months, 67% of the women (n=72) in the intervention group and 63% of the women (n=71) in the control group (p=0.84) became pregnant. The cumulative incidence of GDM among the women available for the final analyses was 60% (n=39/65) in the intervention group and 54% (n=34/63) in the control group (p=0.49). GDM was diagnosed already before 20 weeks of gestation in 60% (n=44/73) of the cases.

Conclusion

The preconceptional lifestyle intervention applied in the present study did not reduce the incidence of GDM.

Heterogeneity of gestational diabetes (GDM) and long-term risk of diabetes and metabolic syndrome: findings from the RADIEL study follow-up

AIMS

To assess the metabolic health of obese and non-obese women at high GDM risk 5 years postpartum.

METHODS

This is a secondary analysis of the 5-year follow-up of the RADIEL GDM prevention study including 333 women at high GDM risk (BMI ≥ 30 kg/m² and/or previous GDM). Five years postpartum metabolic health was assessed including anthropometric measurements, oral glucose tolerance test, lipid metabolism, and body composition as well as medical history questionnaires. For the analysis, we divided the women into four groups based on parity, BMI, and previous history of GDM.

RESULTS

Five years postpartum impaired glucose regulation (IFG, IGT, or diabetes) was diagnosed in 15% of the women; 3.6% had type 2 diabetes. The highest prevalence was observed among obese women with a history of GDM (26%), and the lowest prevalence (8%) among primiparous obese women (p = 0.021). At follow-up 25-39% of the obese women fulfilled the diagnostic criteria for the metabolic syndrome, in the non-obese group 11% (p < 0.001). This was associated with body fat percentage. The non-obese group, however, faced metabolic disturbances (IFG, IGT, diabetes, or metabolic syndrome) at a significantly lower BMI (p < 0.001). Among women who were non-obese before pregnancy, 5 years postpartum, the obesity prevalence based on BMI was 14% and based on body fat percentage 58%.

CONCLUSIONS

The prevalence of impaired glucose regulation and metabolic syndrome is high 5 years postpartum among women at high risk of GDM. There are high-risk women also among the non-obese, who develop metabolic derangements already at a lower BMI.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, www.clinicaltrials.com , NCT01698385.

Effects of a Lifestyle Intervention During Pregnancy and First Postpartum Year: Findings From the RADIEL Study

CONTEXT

Women with a history of gestational diabetes (GDM) have a sevenfold risk of developing type 2 diabetes.

OBJECTIVE

To assess the effects of a lifestyle intervention during pregnancy and first postpartum year on glucose regulation, weight retention, and metabolic characteristics among women at high GDM risk.

DESIGN

In the Finnish Gestational Diabetes Prevention study, trained study nurses provided lifestyle counseling in each trimester and 6 weeks, 6 months, and 12 months postpartum.

SETTING

Three maternity hospitals in the Helsinki area and one in Lappeenranta.

PATIENTS

In total, 269 women with previous GDM and/or a prepregnancy body mass index ≥30 kg/m2 were enrolled before 20 gestational weeks and allocated to either a control or an intervention group. This study includes the 200 participants who attended study visits 6 weeks and/or 12 months postpartum.

INTERVENTION

The lifestyle intervention followed Nordic diet recommendations and at least 150 minutes of moderate exercise was recommended weekly.

MAIN OUTCOME MEASURE

The incidence of impaired glucose regulation (impaired fasting glucose, impaired glucose tolerance, or type 2 diabetes) during the first postpartum year.

RESULTS

Impaired glucose regulation was present in 13.3% of the women in the control and in 2.7% in the intervention group [age-adjusted odds ratio, 0.18 (95% confidence interval, 0.05 to 0.65), P = 0.009] during the first postpartum year. There were no differences between the groups in weight retention, physical activity, or diet at 12 months postpartum.

CONCLUSIONS

A lifestyle intervention during pregnancy and the first postpartum year successfully reduced the incidence of postpartum impairment in glucose regulation.

Interconception care for women with a history of gestational diabetes for improving maternal and infant outcomes

BACKGROUND

Gestational diabetes mellitus (GDM) is associated with adverse health outcomes for mothers and their infants both perinatally and long term. Women with a history of GDM are at risk of recurrence in subsequent pregnancies and may benefit from intervention in the interconception period to improve maternal and infant health outcomes.

OBJECTIVES

To assess the effects of interconception care for women with a history of GDM on maternal and infant health outcomes.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register (7 April 2017) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials, including quasi-randomised controlled trials and cluster-randomised trials evaluating any protocol of interconception care with standard care or other forms of interconception care for women with a history of GDM on maternal and infant health outcomes.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility. In future updates of this review, at least two review authors will extract data and assess the risk of bias of included studies; the quality of the evidence will be assessed using the GRADE approach.

MAIN RESULTS

No eligible published trials were identified. We identified a completed randomised controlled trial that was designed to evaluate the effects of a diet and exercise intervention compared with standard care in women with a history of GDM, however to date, it has only published results on women who were pregnant at randomisation (and not women in the interconception period). We also identified an ongoing trial, in obese women with a history of GDM planning a subsequent pregnancy, which is assessing the effects of an intensive lifestyle intervention, supported with liraglutide treatment, compared with usual care. We also identified a trial that was designed to evaluate the effects of a weight loss and exercise intervention compared with lifestyle education also in obese women with a history of GDM planning a subsequent pregnancy, however it has not yet been published. These trials will be re-considered for inclusion in the next review update.

AUTHORS' CONCLUSIONS

The role of interconception care for women with a history of GDM remains unclear. Randomised controlled trials are required evaluating different forms and protocols of interconception care for these women on perinatal and long-term maternal and infant health outcomes, acceptability of such interventions and cost-effectiveness.

Is improvement in the Healthy Food Intake Index (HFII) related to a lower risk for gestational diabetes?

The aim was to analyse whether changes in the Healthy Food Intake Index (HFII) during pregnancy are related to gestational diabetes (GDM) risk. The 251 pregnant women participating had a pre-pregnancy BMI≥30 kg/m2 and/or a history of GDM. A 75 g oral glucose tolerance test (OGTT) was performed during the first and second trimesters of pregnancy for assessment of GDM. A normal OGTT result at first trimester was an inclusion criterion for the study. FFQ collected at first and second trimesters served for calculating the HFII. A higher HFII score reflects higher adherence to the Nordic Nutrition Recommendations (NNR) (score range 0-17). Statistical methods included Student's t test, Mann-Whitney U test, Fisher's exact test and linear and logistic regression analyses. The mean HFII at first trimester was 10·1 (95 % CI 9·7, 10·4) points, and the mean change from the first to the second trimester was 0·35 (95 % CI 0·09, 0·62) points. The range of the HFII changes varied from -7 to 7. The odds for GDM decreased with higher HFII change (adjusted OR 0·83 per one unit increase in HFII; 95 % CI 0·69, 0·99; P=0·043). In the analysis of the association between HFII-sub-indices and GDM, odds for GDM decreased with higher HFII-Fat change (fat percentage of milk and cheese, type of spread and cooking fats) but it was not significant in a fully adjusted model (P=0·058). Dietary changes towards the NNR during pregnancy seem to be related to a lower risk for GDM.

Relationship between observational learning and health belief with physical activity among adolescents girl in Isfahan, Iran

Background:

Physical activities among adolescents affects health during pubescence and adolescence and decrease in physical activities among adolescents has become a global challenge. The aim of the present study was to define the relation between the level of physical activity among adolescent girls and their health beliefs as personal factor and level of observational learning as environmental factor.

Materials and Methods:

The present study was a cross-sectional study that was conducted on 400 students aged from 11 to 19 years in Isfahan, Iran. Information regarding the duration of physical activity with moderate/severe intensity was measured in four dimensions of leisure time (exercising and hiking), daily activities, and transportation-related activities using the International Physical Activity questionnaire. Health belief structures included perceived sensitivity, intensity of perceived threat, perceived benefits, and barriers and self-efficacy; observational learning was measured using a researcher-made questionnaire.

Results:

Results showed that perceived barriers, observational learning, and level of self-efficacy were related to the level of physical activity in all dimensions. In addition, the level of physical activity at leisure time, transportation, and total physical activity were dependent on the intensity of perceived threats (P < 0.05).

Conclusions:

This study showed that the intensity of perceived threats, perceived barriers and self-efficacy structures, and observational learning are some of the factors related to physical activity among adolescent girls, and it is possible that by focusing on improving these variables through interventional programs physical activity among adolescent girls can be improved.