Postprandial walking reduces glucose levels in women with gestational diabetes mellitus

Optimizing postprandial glucose prediction through integration of diet and exercise: Leveraging transfer learning with imbalanced patient data

BACKGROUND

In recent years, numerous methods have been introduced to predict glucose levels using machine-learning techniques on patients' daily behavioral and continuous glucose data. Nevertheless, a definitive consensus remains elusive regarding modeling the combined effects of diet and exercise for optimal glucose prediction. A notable challenge is the propensity for observational patient datasets from uncontrolled environments to overfit due to skewed feature distributions of target behaviors; for instance, diabetic patients seldom engage in high-intensity exercise post-meal.

METHODS

In this study, we introduce a unique application of Bayesian transfer learning for postprandial glucose prediction using randomized controlled trial (RCT) data. The data comprises a time series of three key variables: continuous glucose levels, exercise expenditure, and carbohydrate intake. For building the optimal model to predict postprandial glucose levels we initially gathered balanced training data from RCTs on healthy participants by randomizing behavioral conditions. Subsequently, we pretrained the model's parameter distribution using RCT data from the healthy cohort. This pretrained distribution was then adjusted, transferred, and utilized to determine the model parameters for each patient.

RESULTS

The efficacy of the proposed method was appraised using data from 68 gestational diabetes mellitus (GDM) patients in uncontrolled settings. The evaluation underscored the enhanced performance attained through our method. Furthermore, when modeling the joint impact of diet and exercise, the synergetic model proved more precise than its additive counterpart.

CONCLUSION

An innovative application of the transfer-learning utilizing randomized controlled trial data can improve the challenging modeling task of postprandial glucose prediction for GDM patients, integrating both dietary and exercise behaviors. For more accurate prediction, future research should focus on incorporating the long-term effects of exercise and other glycemic-related factors such as stress, sleep.

Diagnosis to Delivery: A Randomized Clinical Trial of Postmeal Walking in Women with Gestational Diabetes

PURPOSE

The aim of this study was to determine whether advice to perform postmeal walking could be an effective and feasible alternate to standard care continuous walking for the management of gestational diabetes (GDM).

METHODS

Forty women with GDM were randomized between 28 and 30 wk of gestation into either standard care (CTL; 30-min continuous walking, most days per week) or standard care with advice to PMW (daily 10-min walks after three main meals) for ~7 wk. The primary outcome for this randomized controlled trial was postprandial glucose assessed by continuous glucose monitors. Continuous glucose monitor and ActivPAL inclinometers (physical activity parameters) were each worn for 7 d at ~28 and ~35 wk gestation. Delivery outcomes were also collected. A linear mixed model compared the changes across time between groups.

RESULTS

Twenty-six women (PMW: n = 12, CTL: n = 14; age 34 ± 5 y) completed the trial. Mean 3 h postprandial glucose at dinner was higher in the PMW versus CTL group at baseline and across the intervention (main effect group, P = 0.04). Twenty-four hours, nocturnal, and fasting glucose were similar between groups. The PMW group spent ~57 min·d -1 more time sedentary and ~11 min·d -1 less time stepping versus CTL (main effect group: P = 0.02 and 0.05). Adherence to the prescribed 30 min·d -1 of physical activity was high, regardless of whether accumulated as 3 × 10-min or one single bout of walking.

CONCLUSIONS

Distributing activity as 10-min bouts after main meals did not improve postprandial glucose outcomes compared with standard-care control. More research on the optimal duration and intensity of postmeal walks to improve postprandial responses are needed. Strategies that mitigate sedentary time and increase the minutes of physical activity accumulated across the day in pregnancy are also warranted.

Physical activity, gestational weight gain in obese patients with early gestational diabetes and the perinatal outcome - a randomised-controlled trial

BACKGROUND

Excessive gestational weight gain, especially among women with gestational diabetes, is associated with several adverse perinatal outcomes. Our study aimed to analyse the impact of the use of pedometers to supervise physical activity on maternal health and the obstetric outcomes of pregnant women with obesity and early gestational diabetes.

METHODS

124 pregnant patients were enrolled in the presented research.

INCLUSION CRITERIA

singleton pregnancy, age > 18 years, gestational diabetes diagnosed in the first half of pregnancy (< 20th week of pregnancy), obesity according to the American Endocrine Society criteria. Each patient was advised to take at least 5000 steps daily. Patients were randomly assigned to pedometers (N = 62), and were recommended to monitor daily the number of steps. The group without pedometers (N = 62) was not observed. Visit (V1) was scheduled between the 28th and 32nd gestational week (GW), and visit (V2) occurred between the 37th and 39th GW. Anthropometric measurements and blood samples were collected from all patients at each appointment. Foetal and maternal outcomes were analysed at the end of the study.

RESULTS

In the group supervised by pedometers, there were significantly fewer newborns with macrosomia (p = 0,03). Only 45% of patients satisfied the recommended physical activity guidelines. Patients who walked more than 5000 steps per day had significantly higher body weight at baseline (p = 0,005), but weight gain was significantly lower than in the group that did not exceed 5000 steps per day (p < 0,001). The perinatal outcome in the group of patients performing more than 5000 steps did not demonstrate significant differences with when compared to less active group. ROC curve for weight gain above the guidelines indicated a statistically substantial cut-off point for this group at the level of 4210 steps/day (p = 0.00001).

CONCLUSIONS

Monitoring the activity of pregnant patients with gestational diabetes and obesity by pedometers did not have a significantly impact on their metabolic control and weight gain. However, it contributed to less macrosomia. Furthermore, physical activity over 5,000 steps per day positively affects weight loss, as well as contributes to improved obstetric and neonatal outcomes.

Supports and Barriers to Lifestyle Interventions in Women with Gestational Diabetes Mellitus in Australia: A National Online Survey

BACKGROUND

Gestational diabetes mellitus (GDM) affects approximately one in six pregnancies, causing a significant burden on maternal and infant health. Lifestyle interventions are first-line therapies to manage blood glucose levels (BGLs) and prevent future cardiometabolic complications. However, women with GDM experience considerable barriers to lifestyle interventions; thus, the aim of this study was to determine how women with GDM manage their condition and to identify the primary supports and barriers to lifestyle intervention participation.

METHODS

An online cross-sectional survey of women in Australia with a history of GDM was conducted. Questions included participant demographics, strategies used to manage BGLs, physical activity and dietary habits, and barriers and supports to lifestyle interventions.

RESULTS

A total of 665 individuals consented and responded to the advertisement, of which 564 were eligible and provided partial or complete responses to the survey questions. Most respondents were between 35 and 39 years of age (35.5%), not pregnant (75.4%), working part-time (26.7%), university-educated (58.0%), and had only one child (40.1%). Most respondents managed their BGLs through diet (88.3%), with "low-carbohydrate" diets being the most popular (72.3%), and 46.2% of respondents were undertaking insulin therapy. Only 42.2% and 19.8% of respondents reported meeting the aerobic and strengthening exercise recommendations, respectively. Women with one child or currently pregnant expecting their first child were 1.51 times more likely (95% CI, 1.02, 2.25) to meet the aerobic exercise recommendations than those with two or more children. The most common reported barriers to lifestyle intervention participation were "lack of time" (71.4%) and "childcare" commitments (57.7%). Lifestyle interventions delivered between 6 and 12 months postpartum (59.0%), involving an exercise program (82.6%), and delivered one-on-one were the most popular (64.9%).

CONCLUSION

Most women report managing their GDM with lifestyle strategies. The most common strategies reported involve approaches not currently included in the clinical practice guidelines such as reducing carbohydrate consumption. Furthermore, despite being willing to participate in lifestyle interventions, respondents report significant barriers, including lack of time and childcare commitments, whereas mentioned supports included having an online format. Lifestyle interventions for women with a history of GDM should be designed in a manner that is both tailored to the individual and considerate of existing barriers and supports to participation.

Short-term removal of exercise impairs glycemic control in older adults: A randomized trial

Postprandial glycemia (PPG) predicts cardiovascular disease, and short-term physical inactivity increases PPG in young, active adults. Whether this occurs in older, active adults who may be more prone to bouts of inactivity is unknown. This study determined if postprandial interstitial glucose (PPIG) was impaired in active older adults following the removal of exercise for 3 days (NOEX) compared to active young adults. In this randomized, crossover study, 11 older (69.1 ± 1.9 years) and 9 young (32.8 ± 1.8 years) habitually active (≥90 min/week of exercise) adults completed 3-days of NOEX and 3-days of normal habitual exercise (EX), separated by ≥1 week. Diet was standardized across phases. Glycemic control (3-day average) was assessed via continuous glucose monitoring during both phases. Significant main effects of age and phase were detected (p < 0.05), but no interaction was found for steps/day (p > 0.05) (old EX: 6283 ± 607, old NOEX: 2380 ± 382 and young EX: 8798 ± 623, young NOEX: 4075 ± 516 steps/day). Significant main effects of age (p = 0.002) and time (p < 0.001) existed for 1-h PPIG, but no effect of phase or interactions was found (p > 0.05). Significant main effects (p < 0.05) of age (old: 114 ± 1 mg/dl, young: 106 ± 1 mg/dl), phase (NOEX: 112 ± 1 mg/dl, EX: 108 ± 1 mg/dl), and time (0 min: 100 ± 2, 30 min: 118 ± 2, 60 min: 116 ± 2, 90 min: 111 ± 2, 120 min: 108 ± 2 mg/dl) in 2-h PPIG were detected, but no interaction was found (p > 0.05). However, only significant main effects of phase (NOEX: 14 ± 1 and EX:12 ± 1, p > 0.05) were found for 24-h blood glucose standard deviation. Older adults appear to have impaired glycemic control compared to young adults and exercise removal impairs glycemic control in both populations. Yet, the impairment in glycemic control with exercise removal is not different between old and young adults.

Three short postmeal walks as an alternate therapy to continuous walking for women with gestational diabetes

The purpose of this study was to determine whether postmeal walking (breaking up exercise into short bouts after meals) is an effective and feasible alternate to continuous walking for the management of gestational diabetes. Forty-one women with gestational diabetes were randomised between wk 28-30 gestation to either standard-care (30-min continuous exercise) or standard-care with postmeal walking (10-min of walking after breakfast, lunch and dinner). Continuous glucose and activity monitors were worn to measure glycaemic control and adherence during three-days of standard-care (baseline) followed by three-days of postmeal or continuous walking. A linear mixed model analysed the changes from baseline between postmeal and continuous walking, as an average of the three-day periods. Thirty-two women (postmeal walking n=17: control n=15, 33±5 y, body mass index 25±4 kg.m2) completed the trial. Postprandial and overnight glucose concentrations were similar between postmeal walking and control, both interventions improved from baseline. There was no difference in adherence between groups, however postmeal walking completed more minutes of prescribed physical activity across baseline and intervention days compared to the continuous walking standard-care group. Preliminary findings from this proof-of-concept study suggest postmeal walking could be a promising alternative to, and work interchangeably with, traditional advice to perform continuous moderate-intensity physical activity, in women with gestational diabetes. Novelty bullets -Three ten-minute postmeal walks may be comparable to thirty minutes continuous walking for glucose control in women with gestational diabetes - Accumulating activity in short bouts after meals is a feasible alternate to continuous exercise for women with gestational diabetes.

The Influence of Practising Physical Activity on the Prevention and Treatment of Gestational Diabetes: A Systematic Review

BACKGROUND

During pregnancy, maintaining an inadequate lifestyle (bad eating habits, stress, consumption of toxic substances, etc.) generates complications such as pre-eclampsia, overweight, lumbar pain and Gestational Diabetes.

OBJECTIVE

This review was carried out with the objective to determine the influence of practising physical activity on the prevention and treatment of Gestational Diabetes; and to evaluate the efficacy of interventions based on therapeutic exercise in the management of such diseases.

METHOD

A systematic review of the publications of the last five years in Medline, Pubmed, Web of Science and Cinahl databases was conducting with the terms Exercise and Gestational Diabetes.

RESULTS

25 articles were found, 9 were observational studies that analysed physical activity habits through questionnaires, and other 16 applied an intervention. With respect to the frequency of the sessions, most of these studies applied their interventions three times per week, with all of them obtaining positive results. Regarding intensity, all the studies that referred to it concluded that it must be at least moderate, highlighting that, at all times, the limitations of pregnant women must be taken into account.

CONCLUSION

Both for the prevention and treatment of this disease, the physical activity must be performed for a minimum of three times per week, at least in moderate intensity, and must be based on aerobic, resistance and strength exercises.

Sedentary behaviors and gestational diabetes mellitus: A systematic review

AIM

Sedentary behaviors are activities that expend less energy than 1.5 metabolic equivalents, such as watching TV, sitting. We aim to systematically review the evidence to determine the association of sedentary behavior (SB) with the risk of gestational diabetes mellitus, and the associations of SB with health outcomes in pregnant women with gestational diabetes mellitus (GDM) and women at high risk of gestational diabetes mellitus.

METHODS

Two researchers independently performed a literature search using PubMed, Medline, EMBASE, CINAHL, the Cochrane Library, the Rehabilitation and Sports Medicine Source, and the Sedentary Behavior Research Database for studies published up to January 27, 2021. Randomized controlled trials, quasi-experimental studies, and observational studies were screened and selected if SB was assessed in the context of gestational diabetes mellitus. Two reviewers extracted the relevant information and independently assessed the included studies for quality and bias.

RESULTS

Eighteen studies were included, involving 60 804 patients, and the timeline of the original study included was from 2006 to 2021. Our review showed that SB before pregnancy was not associated with the risk of gestational diabetes mellitus, while SB during pregnancy was uncertain about the risk of gestational diabetes mellitus. In addition, there were significant associations between SB time and metabolic outcomes. In addition, SB may cause some adverse maternal and fetal outcomes.

CONCLUSION

SB is likely to be the intermediary variable between occurrence of GDM and adverse maternal and infant outcome, rather than a direct influencing factor. Limited by the quantity and quality of included studies, the above conclusions need to be verified by more high-quality studies.

Postprandial interval walking-effect on blood glucose in pregnant women with gestational diabetes

BACKGROUND

During pregnancy, postprandial hyperglycemia may increase the risk of complications such as fetal macrosomia. However, evidence on beneficial effects of physical activity on postprandial hyperglycemia is sparse.

OBJECTIVE

This study aimed to investigate the effect of 20 minutes of postprandial interval walking on glycemic control and glycemic variability in pregnant women diagnosed as having gestational diabetes mellitus.

STUDY DESIGN

A crossover controlled trial including 14 pregnant women (gestational age 31.8±1.3 weeks) diagnosed as having gestational diabetes mellitus (75 g oral glucose load with 2-hour venous plasma glucose of ≥9.0 mmol/L) was conducted. Participants completed a 4-day intervention period and a 4-day control period with 3 days in between. In each study period, participants received a fixed and identical diet. In the intervention period, participants engaged in 20 minutes of postprandial interval walking after breakfast, lunch, and dinner. Interval walking comprised alternating 3 minutes of slow and fast intervals. Interstitial glucose concentrations were determined during both study periods with a continuous glucose monitor. The mixed effects model was used to compare differences between exercise and no exercise.

RESULTS

Of note, 20 minutes of postprandial interval walking significantly reduced glycemic control during daytime hours relative to the control period (4-day mean glucose, 5.31 [5.04-5.59] vs 5.53 [5.25-5.81] mmol/L [95.6 (90.7-100.6) vs 99.5 (94.5-104.6) mg/dL]; P<.05). On each individual trial day, interval walking significantly reduced glycemic control during daytime hours on day 1 (mean glucose, 5.19 [4.92-5.47] vs 5.55 [5.27-5.83] mmol/L [93.4 (88.6-98.5) vs 99.9 (94.9-104.9) mg/dL]; P=.00), day 2 (mean glucose, 5.32 [5.05-5.60] vs 5.57 [5.29-5.84] mmol/L [95.8 (90.9-100.8) vs 100.3 (95.2-105.1) mg/dL]; P=.00), and day 3 (mean glucose, 5.27 [5.00-5.54] vs 5.46 [5.19-5.74] mmol/L [94.9 (90.0-99.7) vs 98.3 (93.4-103.3) mg/dL]; P=.00), but not on day 4.

CONCLUSION

A total of 20 minutes of postprandial interval walking seems to be an effective way to control postprandial glucose excursions in women with gestational diabetes mellitus.

Physical activity for blood glucose control in gestational diabetes mellitus: rationale and recommendations for translational behavioral interventions

Gestational Diabetes Mellitus (GDM) is associated with adverse health outcomes during pregnancy and beyond. Previous randomized controlled trials of exercise interventions have demonstrated that exercise, conducted primarily during supervised sessions, improves maternal glycemic control in women with GDM. However, additional research is needed to develop physical activity interventions that are easily implemented in healthcare settings (e.g., recommendations and strategies to increase non-supervised physical activity). This narrative review presents: current physical activity recommendations for pregnancy and women with GDM; the scientific literature to date on physical activity, particularly walking, and blood glucose control in GDM; rationale for physical activity interventions targeting women with GDM that are appropriate for translation to the clinical setting (e.g., lifestyle interventions that include behavioral counseling with a health coach); and the strategies employed by previous, successful lifestyle interventions for pregnant and postpartum women that were based in clinical settings.Most previous exercise interventions for blood glucose control in women with GDM have included supervised exercise sessions, and will thus be difficult to translate to the health care system. However, lifestyle interventions for weight maintenance (i.e., healthy diet and physical activity) set in the health care system and delivered by health coaches have been successfully implemented in pregnant and postpartum populations. Therefore, we suggest that future trials examine lifestyle interventions that promote unsupervised walking with evidence-based behavioral strategies (e.g., goal setting, monitoring, and feedback) and consider incorporating the use of physical activity tracking devices to support these strategies.

Exercise as a Therapeutic Intervention in Gestational Diabetes Mellitus

Gestational Diabetes Mellitus (GDM) is defined as any degree of glucose intolerance with onset or first recognition during pregnancy. Regular exercise is important for a healthy pregnancy and can lower the risk of developing GDM. For women with GDM, exercise is safe and can affect the pregnancy outcomes beneficially. A single exercise bout increases skeletal muscle glucose uptake, minimizing hyperglycemia. Regular exercise training promotes mitochondrial biogenesis, improves oxidative capacity, enhances insulin sensitivity and vascular function, and reduces systemic inflammation. Exercise may also aid in lowering the insulin dose in insulin-treated pregnant women. Despite these benefits, women with GDM are usually inactive or have poor participation in exercise training. Attractive individualized exercise programs that will increase adherence and result in optimal maternal and offspring benefits are needed. However, as women with GDM have a unique physiology, more attention is required during exercise prescription. This review (i) summarizes the cardiovascular and metabolic adaptations due to pregnancy and outlines the mechanisms through which exercise can improve glycemic control and overall health in insulin resistance states, (ii) presents the pathophysiological alterations induced by GDM that affect exercise responses, and (iii) highlights cardinal points of an exercise program for women with GDM.

Accumulating Physical Activity in Short or Brief Bouts for Glycemic Control in Adults With Prediabetes and Diabetes

Clinical practice guidelines on physical activity and diabetes currently stipulate physical activity can be accumulated in bouts of ≥10 minutes to meet recommendations for health benefits. Individuals are also encouraged to interrupt prolonged sitting with brief activity breaks of ∼1 to 5 minutes in duration. Growing research highlights accumulating activity in shorter bouts across the day as a potential strategy to improve glycemic control and to help those who are largely sedentary meet physical activity guidelines. Research has shown favourable glycemic benefits for postprandial glucose and glycated hemoglobin with either 3 short (10 to 15 minutes) or frequent brief (1 to 5 minutes) bouts of activity spread around meals or throughout the day. To date, most studies examining accumulated activity were done with people with type 2 diabetes compared with sedentary conditions, were short term and measured various indices of glycemic control using continuous glucose monitoring. The 7 trials comparing accumulating 3 short bouts to a single bout showed comparable benefits for glycemic control (i.e. fasting glucose, 24 h mean glucose and postprandial hyperglycemia). Furthermore, timing short bouts around meals may improve postprandial glucose and hyperglycemia more than a single bout. It is unknown whether a threshold for the duration of accumulated bouts exists---that is, "how much is enough?" In this narrative review, we focus on the glycemic effects of physical activity accumulated in short or brief bouts for people with prediabetes and diabetes as compared with a single continuous bout. Given that poor adherence to physical activity recommendations and that fewer opportunities exist in modern societies for incidental (nonexercise) physical activity, accumulating activity may be a choice strategy for improving glycemic control in those with and at risk of diabetes.

Diet and Healthy Lifestyle in the Management of Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) among pregnant women increases the risk of both short-term and long-term complications, such as birth complications, babies large for gestational age (LGA), and type 2 diabetes in both mother and offspring. Lifestyle changes are essential in the management of GDM. In this review, we seek to provide an overview of the lifestyle changes which can be recommended in the management of GDM. The diet recommended for women with GDM should contain sufficient macronutrients and micronutrients to support the growth of the foetus and, at the same time, limit postprandial glucose excursions and encourage appropriate maternal gestational weight gain. Blood glucose excursions and hyperglycaemic episodes depend on carbohydrate-intake. Therefore, nutritional counselling should focus on the type, amount, and distribution of carbohydrates in the diet. Further, physical activity has beneficial effects on glucose and insulin levels and it can contribute to a better glycaemic control.

Cycling reduces blood glucose excursions after an oral glucose tolerance test in pregnant women: a randomized crossover trial

The aim of this study was to evaluate the effect of an acute bout of cycling immediately after oral glucose intake on glucose metabolism in pregnant women at risk for gestational diabetes mellitus (GDM). Fifteen pregnant women with BMI ≥ 27 kg/m² were enrolled in a randomized crossover controlled study and underwent two oral glucose tolerance tests (OGTTs) ingesting 75 g of glucose followed by either 20 min of stationary cycling at moderate intensity (65%-75% maximal heart rate) or rest. Using continuous glucose monitors, glucose was measured up to 48 h after the OGTT. Glucose, insulin, and C-peptide were determined at baseline and after 1 and 2 h. One hour after glucose intake, mean blood glucose was significantly lower after cycling compared with rest (p = 0.002). Similarly, mean glucose peak level was significantly lower after cycling compared with after rest (p = 0.039). Lower levels of insulin and C-peptide were observed after 1 h (p < 0.01). Differences in glucose measurements after 2 h and up to 48 h were not statistically different. We found that 20 min of cycling at moderate intensity after glucose intake reduced blood glucose excursions in pregnant women at risk for GDM. ClinicalTrials.gov Identifier: NCT03644238. Novelty Bullets In pregnant women, we found that cycling after glucose intake resulted in significantly lower glucose levels compared with rest. The exercise intervention studied is feasible for pregnant women and could be readily used to reduce glucose excursions.

The Use of Non-insulin Agents in Gestational Diabetes: Clinical Considerations in Tailoring Therapy

PURPOSE OF REVIEW

To assess evidence to date for use of non-insulin agents in treatment of gestational diabetes mellitus.

RECENT FINDINGS

There has been increasing interest in the use of non-insulin agents, primarily metformin and glyburide (which both cross the placenta). Metformin has been associated with less maternal weight gain; however, recent studies have shown a trend toward increased weight in offspring exposed to metformin in utero. Glyburide has been associated with increased neonatal hypoglycemia. Glycemic control during pregnancy is essential to optimize both maternal and fetal outcomes. There are a myriad of factors to consider when designing treatment programs including patient preference, phenotype, and glucose patterns. While insulin is typically recommended as first-line, some women refuse or cannot afford insulin and in those cases, non-insulin agents may be used. Further studies are needed to assess treatment in pregnancy, perinatal outcomes, and particularly long-term metabolic profiles in mothers and offspring.

Gestational Diabetes Mellitus

Although it has been accepted for decades that women with gestational diabetes mellitus (GDM) are at high risk for future development of type 2 diabetes, vigorous debate regarding the value of detecting and treating GDM has persisted into the twenty-first century. Although results from 2 randomized trials provide strong evidence that treating GDM reduces adverse perinatal outcomes, it remains to be determined whether treatment impacts long-term offspring outcomes. Insulin is the first-line pharmacologic treatment and is added when glycemic goals are not met with nutritional modifications. Oral agent use is controversial, as data on long-term offspring outcomes are lacking.

Exercise in Pregnant Women with Diabetes

PURPOSE OF REVIEW

Diabetes affects an increasing number of pregnancies. Regular exercise is recommended for pregnant women without diabetes, but whether exercise during pregnancy also benefits women with gestational diabetes (GDM) or preexisting (type 1 or type 2) diabetes or if these women have any specific risks is unclear.

RECENT FINDINGS

Recent evidence suggests that low- to moderate-intensity exercise improves blood glucose and may delay insulin initiation for women with GDM. Exercise is also safe, with no reports of increased maternal or neonatal complications. Few studies evaluated exercise as adjunct therapy for pregnant women with preexisting diabetes, precluding a thorough assessment in this population. Low- to moderate-intensity exercise during pregnancy safely improves glycemic control among women with GDM. More studies are needed to evaluate the impact of exercise in pregnant women with preexisting diabetes. Whether a specific type, volume, or timing of activity is most effective is not known.

Patterns of leisure-time physical activity across pregnancy and adverse pregnancy outcomes

Background

Although leisure-time physical activity (PA) contributes to overall health, including pregnancy health, patterns across pregnancy have not been related to birth outcomes. We hypothesized that women with sustained low leisure-time PA would have excess risk of adverse pregnancy outcomes, and that changing patterns across pregnancy (high to low and low to high) may also be related to risk of adverse pregnancy outcomes.

Methods

Nulliparous women (n = 10,038) were enrolled at 8 centers early in pregnancy (mean gestational age in weeks [SD] = 12.05 [1.51]. Frequency, duration, and intensity (metabolic equivalents) of up to three leisure activities reported in the first, second and third trimesters were analyzed. Growth mixture modeling was used to identify leisure-time PA patterns across pregnancy. Adverse pregnancy outcomes (preterm birth, [PTB, overall and spontaneous], hypertensive disorders of pregnancy [HDP], gestational diabetes [GDM] and small-for-gestational-age births [SGA]) were assessed via chart abstraction.

Results

Five patterns of leisure-time PA across pregnancy were identified: High (35%), low (18%), late decreasing (24%), early decreasing (10%), and early increasing (13%). Women with sustained low leisure-time PA were younger and more likely to be black or Hispanic, obese, or to have smoked prior to pregnancy. Women with low vs. high leisure-time PA patterns had higher rates of PTB (10.4 vs. 7.5), HDP (13.9 vs. 11.4), and GDM (5.7 vs. 3.1, all p < 0.05). After adjusting for maternal factors (age, race/ethnicity, BMI and smoking), the risk of GDM (Odds ratio 2.00 [95% CI 1.47, 2.73]) remained higher in women with low compared to high patterns. Early and late decreasing leisure-time PA patterns were also associated with higher rates of GDM. In contrast, women with early increasing patterns had rates of GDM similar to the group with high leisure-time PA (3.8% vs. 3.1%, adjusted OR 1.16 [0.81, 1.68]). Adjusted risk of overall PTB (1.31 [1.05, 1.63]) was higher in the low pattern group, but spontaneous PTB, HDP and SGA were not associated with leisure-time PA patterns.

Conclusions

Sustained low leisure-time PA across pregnancy is associated with excess risk of GDM and overall PTB compared to high patterns in nulliparous women. Women with increased leisure-time PA early in pregnancy had low rates of GDM that were similar to women with high patterns, raising the possibility that early pregnancy increases in activity may be associated with improved pregnancy health.

Trial registration

Registration number NCT02231398.

Electronic supplementary material

The online version of this article (10.1186/s12966-018-0701-5) contains supplementary material, which is available to authorized users.