Variations in resting energy expenditure: impact on gestational weight gain

Risk factors for inadequate and excessive gestational weight gain in 25 low- and middle-income countries: An individual-level participant meta-analysis

BACKGROUND

Many women experience suboptimal gestational weight gain (GWG) in low- and middle-income countries (LMICs), but our understanding of risk factors associated with GWG in these settings is limited. We investigated the relationships between demographic, anthropometric, lifestyle, and clinical factors and GWG in prospectively collected data from LMICs.

METHODS AND FINDINGS

We conducted an individual participant-level meta-analysis of risk factors for GWG outcomes among 138,286 pregnant women with singleton pregnancies in 55 studies (27 randomized controlled trials and 28 prospective cohorts from 25 LMICs). Data sources were identified through PubMed, Embase, and Web of Science searches for articles published from January 2000 to March 2019. Titles and abstracts of articles identified in all databases were independently screened by 2 team members according to the following eligibility criteria: following inclusion criteria: (1) GWG data collection took place in an LMIC; (2) the study was a prospective cohort or randomized trial; (3) study participants were pregnant; and (4) the study was not conducted exclusively among human immunodeficiency virus (HIV)-infected women or women with other health conditions that could limit the generalizability of the results. The Institute of Medicine (IOM) body mass index (BMI)-specific guidelines were used to determine the adequacy of GWG, which we calculated as the ratio of the total observed weight gain over the mean recommended weight gain. Study outcomes included severely inadequate GWG (percent adequacy of GWG <70), inadequate GWG (percent adequacy of GWG <90, inclusive of severely inadequate), and excessive GWG (percent adequacy of GWG >125). Multivariable estimates from each study were pooled using fixed-effects meta-analysis. Study-specific regression models for each risk factor included all other demographic risk factors measured in a particular study as potential confounders, as well as BMI, maternal height, pre-pregnancy smoking, and chronic hypertension. Risk factors occurring during pregnancy were further adjusted for receipt of study intervention (if any) and 3-month calendar period. The INTERGROWTH-21st standard was used to define high and low GWG among normal weight women in a sensitivity analysis. The prevalence of inadequate GWG was 54%, while the prevalence of excessive weight gain was 22%. In multivariable models, factors that were associated with a higher risk of inadequate GWG included short maternal stature (<145 cm), tobacco smoking, and HIV infection. A mid-upper arm circumference (MUAC) of ≥28.1 cm was associated with the largest increase in risk for excessive GWG (risk ratio (RR) 3.02, 95% confidence interval (CI) [2.86, 3.19]). The estimated pooled difference in absolute risk between those with MUAC of ≥28.1 cm compared to those with a MUAC of 24 to 28.09 cm was 5.8% (95% CI 3.1% to 8.4%). Higher levels of education and age <20 years were also associated with an increased risk of excessive GWG. Results using the INTERGROWTH-21st standard among normal weight women were similar but attenuated compared to the results using the IOM guidelines among normal weight women. Limitations of the study's methodology include differences in the availability of risk factors and potential confounders measured in each individual dataset; not all risk factors or potential confounders of interest were available across datasets and data on potential confounders collected across studies.

CONCLUSIONS

Inadequate GWG is a significant public health concern in LMICs. We identified diverse nutritional, behavioral, and clinical risk factors for inadequate GWG, highlighting the need for integrated approaches to optimizing GWG in LMICs. The prevalence of excessive GWG suggests that attention to the emerging burden of excessive GWG in LMICs is also warranted.

MIDO GDM: an innovative artificial intelligence-based prediction model for the development of gestational diabetes in Mexican women

Given the barriers to early detection of gestational diabetes mellitus (GDM), this study aimed to develop an artificial intelligence (AI)-based prediction model for GDM in pregnant Mexican women. Data were retrieved from 1709 pregnant women who participated in the multicenter prospective cohort study 'Cuido mi embarazo'. A machine-learning-driven method was used to select the best predictive variables for GDM risk: age, family history of type 2 diabetes, previous diagnosis of hypertension, pregestational body mass index, gestational week, parity, birth weight of last child, and random capillary glucose. An artificial neural network approach was then used to build the model, which achieved a high level of accuracy (70.3%) and sensitivity (83.3%) for identifying women at high risk of developing GDM. This AI-based model will be applied throughout Mexico to improve the timing and quality of GDM interventions. Given the ease of obtaining the model variables, this model is expected to be clinically strategic, allowing prioritization of preventative treatment and promising a paradigm shift in prevention and primary healthcare during pregnancy. This AI model uses variables that are easily collected to identify pregnant women at risk of developing GDM with a high level of accuracy and precision.

The Mediating Role of Body Mass Index in the Association Between Age at First Childbirth and Lung Function Among Chinese Postmenopausal Women

Objective

Little is known about the effect of age at first childbirth on lung function. We aimed to investigate the association between age at first childbirth and lung function in Chinese women and further test whether this association is mediated by body mass index (BMI).

Methods

This cross-sectional study is a partial survey of the China Kadoorie Biobank (CKB) which was conducted in Xinxiang City, Henan Province between 2004 and 2008. A total of 16,584 postmenopausal women aged 30-79 years were enrolled. Multiple linear and logistic regression were used to investigate the association between age at first childbirth and lung function and overweight/obesity. The mediation analysis was performed using the PROCESS procedure for SPSS.

Results

The mean (SD) age at first childbirth was 23.1 (2.7) years. Women with first childbirth aged ≤19 years and 20-22 years had lower lung function than women who gave first childbirth aged 23-25 years. Per 1-year increase in the age at first childbirth was associated with a 3.31 mL increase in FEV1 (95% CI = 1.27-5.35), 3.91 mL increase in FVC (95% CI = 1.63-6.18), 0.15% increase in FEV1, % predicted (95% CI = 0.05-0.24) and 0.14% increase in FVC, % predicted (95% CI = 0.05-0.22). There was no clear association between age at first childbirth and FEV1/FVC ratio. BMI played a contribution to the association between age at first childbirth and FEV1 and the proportion was 16.4% (indirect effect: β = 0.65, 95% CI = 0.46-0.89; total effect: β = 3.96, 95% CI = 1.92-5.99). Similarly, the proportion to FVC, FEV1, % predicted, and FVC, % predicted was 25.0%, 16.6%, and 25.0%, respectively.

Conclusion

Early age at first childbirth was associated with lower lung function and BMI mediated the association. It is important to test lung function and popularize the knowledge of weight control in women who gave first childbirth at an early age.

Feasibility and user acceptability of Breezing™, a mobile indirect calorimetry device, in pregnant women with overweight or obesity

Emerging evidence has suggested that prenatal resting energy expenditure (REE) may be an important determinant of gestational weight gain. Advancements in technology such as the real-time, mobile indirect calorimetry device (Breezing™) have offered the novel opportunity to continuously assess prenatal REE while also potentially capturing fluctuations in REE. The purpose of this study was to examine feasibility and user acceptability of Breezing™ to assess weekly REE from 8-36 weeks gestation in pregnant women with overweight or obesity participating in the Healthy Mom Zone intervention study. Participants (N=27) completed REE assessments once per week from 8-36 gestation using Breezing™. Feasibility of the device was calculated as compliance (# of weeks used/total # of weeks). User acceptability was measured by asking women to report on the device's enjoyability and barriers. Median compliance was 68%. However, when weeks women experienced technical difficulties (11 of 702 total events) and the device was unavailable were removed (13 of 702 total events), median compliance increased to 71%. Over half (56%) of the women reported that the device was enjoyable or they had neutral feelings about it whereas the remaining 44% reported that it was not enjoyable. The most common barrier reported (44%) was the experience of technical issues. Study compliance data suggest the feasibility of using Breezing™ to assess prenatal REE is promising. However, acceptability data suggest future interventionists should develop transparent and informative protocols to address any barriers prior to implementing the device to increase use.

Management of gestational weight gain in obese or overweight women based on resting energy expenditure: A pilot cohort study

Resting energy expenditure (REE) comprises 60% of total energy expenditure and variations may be associated with gestational weight gain (GWG). This study aims to explore the usability and feasibility of REE guided intervention for GWG in obese and overweight women. We conducted a prospective cohort study in LuHe Hospital of Capital Medical University in Beijing, China between May 1, 2017 and May 31, 2018. Obese/overweight women who had routine prenatal care visit at 10 to 13 weeks of gestation, were recruited after written informed consent was obtained. The intervention group (those women who were recruited between January 1 and May 31, 2018) used REE calculated daily total energy to manage GWG, while the control group (those women who were recruited between May 1 and December 31, 2017) used prepregnancy body mass index calculated daily total energy to manage GWG. GWG and daily total energy between the 2 groups were recorded from 10 to 13 weeks of gestation to delivery. A total of 68 eligible women (35 in intervention group and 33 in control group) were included in the final analysis. Daily total energy in the intervention group increased less than the control group, especially from 2nd trimester to 3rd trimester (1929.54 kcal/d vs. 2138.33 kcal/d). The variation of daily total energy from 1st trimester to 3rd trimester in the intervention group was lower than the control group (226.17 kcal/d vs 439.44 kcal/d). Overall GWG of the intervention group (13.45 kg) was significantly lower than the control group (18.20 kg). The percentage of excess-GWG in the intervention group (31.42%) was also significantly lower than the control (57.57%). Findings from our pilot study suggest that diet recommendation basting on REE may improve management of GWG in obese/overweight women.

Effect of Exercise on the Resting Metabolic Rate and Substrate Utilization in Women with Gestational Diabetes Mellitus: Results of a Pilot Study

Regular physical activity during pregnancy has a positive effect on the mother and fetus. However, there is scarce data regarding the effect of exercise in pregnancies complicated by gestational diabetes mellitus (GDM). The aim of the present parallel, non-randomized, open-label, pilot, clinical study was to examine the effect of two exercise programs on the resting metabolic rate (RMR) and substrate utilization in pregnancies complicated by GDM, compared with usual care (advice for the performance of exercise). Forty-three pregnant women diagnosed with GDM between the 24th and 28th gestational week, volunteered to participate. Three groups were formed: Usual care (n = 17), Walking (n = 14), and Mixed Exercise (n = 12). The Usual care group was given advice on maintaining habitual daily activities without any additional exercise. The Walking group exercised regularly by walking, in addition to the habitual daily activities. Finally, the Mixed Exercise group participated in a program combining aerobics and strength exercises. Training intensity was monitored continuously using lightweight, wearable monitoring devices. The Walking and Mixed Exercise groups participated in the training programs after being diagnosed with GDM and maintained them until the last week of gestation. RMR and substrate utilization were analyzed using indirect calorimetry for all participants twice: between 27th and 28th gestational week and as close as possible before delivery. No differences were observed between groups regarding body composition, age, and medical or obstetrical parameters before or after the exercise programs. RMR was increased after the completion of the exercise interventions in both the Walking (p = 0.001) and the Mixed Exercise arms (p = 0.002). In contrast, substrate utilization remained indifferent. In conclusion, regular exercise of moderate intensity (either walking, or a combination of aerobic and strength training) increases RMR in women with GDM compared to the lack of systematic exercise. However, based on the present, pilot data, these exercise regimes do not appear to alter resting substrate utilization.

Effects of Low Protein-High Carbohydrate Diet during Early and Late Pregnancy on Respiratory Quotient and Visceral Adiposity

Background

Low Protein-High Carbohydrate (LPHC) diet during pregnancy is considered a nutritional and health problem related to the development of maternal metabolic alterations, such as fatty liver and obesity in the perinatal and postnatal period. It is known that increase in visceral adiposity tissue (VAT) modulates maternal metabolic rate, with the respiratory quotient (RQ) being a parameter related to that variable; however, it is unknown whether LPHC intake during pregnancy affects the VAT and the RQ. In this study, we examine if consumption of LPHC during pregnancy modifies the VAT and RQ in early and late periods of pregnancy.

Methods

This is a longitudinal and cross-sectional study with Wistar rats during gestation (G) (3, 8, 15, and 20) and nonpregnant rats. Rats were fed with a control diet with 63/18% carbohydrate/protein and an experimental diet with 79/6% carbohydrate/protein. We studied water and food consumption and metabolic parameters such as RQ and energy expenditure (EE), calculated by indirect calorimetry. In the cross-sectional study, we determined visceral fat, as well as the concentration of free fatty acids, insulin, glucose, and lipid profile in serum.

Results

Nonpregnant rats with LPHC intake decreased significantly in VAT (86%) and the RQ (18%); in pregnant rats in early (8G) and late pregnancy (15G) in LPHC diet, both parameters (VAT and RQ) (25%-92%) increased during light time. When comparing time points during pregnancy in the control and LPHC groups, the RQ increased in 15G during daytime compared to 8G during the night period (17 and 5%, respectively). In late pregnancy, LPHC intake and triacylglyceride levels increased and cholesterol and glucose decreased (45 and 26%, respectively), in comparison to nonpregnant rats.

Conclusions

LPHC intake in nonpregnant rats decreases the RQ and VAT. Interestingly, the opposite occurs in early pregnancy: the RQ and VAT increased, and this correlates with free fatty acid (FFA) levels. The increase in RQ and VAT during light time in early pregnancy increased mobilization of carbohydrate and protein metabolism. These results suggest that LPHC intake during pregnancy increases the glucose metabolism as a compensatory mechanism for energy needs in the fetus and the mother in early pregnancy.

Prepregnancy weight change associated with high gestational weight gain

OBJECTIVE

Gestational weight gain (GWG) above recommendations is a risk factor for adverse maternal, perinatal, and long-term outcomes. This study hypothesized that prepregnancy weight gain may portend excess GWG.

METHODS

Among 1,126 women (51% of whom were of Black race) in the Coronary Artery Risk Development in Young Adults (CARDIA) study with post-baseline births, the prepregnancy annual rate of BMI change per woman was estimated (slope; 5 years before pregnancy) and was related to the risk of GWG above Institute of Medicine recommendations using mixed-effects models (binary) and GWG z score (continuous), adjusting for confounders, and stratified by prepregnancy overweight/obesity status.

RESULTS

A total of 626 women (56%) had excess GWG. Each standard deviation increase in prepregnancy BMI (0.16 kg/m2 per year) was associated with an 18% increased risk of excess GWG (95% CI: 1.13-1.23), adjusted for covariates. Stratified results showed an association for women without overweight or obesity (adjusted relative risk = 1.71 [95% CI: 1.38-2.13]) but not among those with overweight or obesity (adjusted relative risk = 0.98 [95% CI: 0.91-1.05]). When evaluated as a z score, prepregnancy weight gain was associated with higher GWG among women with and without overweight or obesity (mean = 0.24 [0.10] and 0.28 [0.12] z score, respectively).

CONCLUSIONS

Weight gain before pregnancy is associated with higher GWG during pregnancy. Assessment of prepregnancy weight changes may identify those at risk for high GWG.

Low Resting Energy Expenditure Is Associated with High Gestational Weight Gain Only When Resting Energy Expenditure Fluctuates

Resting energy expenditure (REE) may be useful for individualizing energy intake (EI) and physical activity (PA) goals, and in turn, regulating gestational weight gain (GWG). Limited research, however, has examined the association between REE and GWG. This study examined (1) change in REE from 14 to 28 gestation, (2) time-varying associations between REE and GWG, and (3) EI and PA patterns during the weeks when REE and GWG were significantly associated. Pregnant women with overweight/obesity (N = 27) participating in the Healthy Mom Zone study completed weekly point estimates of EI (back-calculation), PA (wrist-worn activity monitor), REE (mobile metabolism device), and weight (Wi-Fi scale) from 14 to 28 weeks gestation. Analyses included descriptives and time-varying effect modeling. REE fluctuated, increasing on average from 14 to 28 weeks gestation, but decreased at gestational weeks 17, 20, 21, 23, 26, and 28. Most women increased in REE; however there was large between-person variability in the amount of change. Associations between REE and GWG were small but time-varying; low REE was associated with high GWG between gestational weeks 25 to 28 when there was observably larger fluctuation in REE. Moreover, over half of the women were categorized as having excessive EI and most as low active during this time. EI needs may be overestimated and PA needs may be underestimated when REE is fluctuating, which may increase the risk for high second trimester GWG. Researchers should consider the role of REE to inform EI and PA goals to regulate GWG.

Diet, Physical Activity and Gestational Weight Gain Patterns among Pregnant Women Living with Obesity in the North East of England: The GLOWING Pilot Trial

Maternal diet, physical activity (PA) behaviours, and gestational weight gain (GWG) are important for optimum health of women and their babies. This secondary analysis of the GLOWING pilot cluster trial explored these among women living with obesity in high deprivation. Pregnant women completed food frequency, PA and psychosocial questionnaires. Weights were retrieved from medical records and measured during routine appointments with midwives. Descriptive and regression analyses were stratified by obesity class. A total of 163 women were recruited; 54.0% had class 1 obesity, 25.8% class 2, 20.2% class 3, and 76.1% lived in the two most deprived quintiles. Women had suboptimal dietary intake, particularly for oily fish, fruit and vegetables. PA was predominantly light intensity, from household, care and occupational activities. Most women gained weight outside of Institute of Medicine (IOM) guideline recommendations (87.8%); women in class 3 obesity were most likely to have inadequate GWG below IOM recommendations (58.3%, p < 0.01) and reduced odds of excessive GWG compared with class 1 (AOR 0.13, 95% 0.04-0.45). Deprived women with obesity have a double inequality as both increase pregnancy risks. This population requires support to meet guideline recommendations for diet, PA and GWG. Further research exploring obesity classes would inform policies and care to achieve the best pregnancy outcomes.

Why Pregnancy Weight Gain Guidelines Need to Differ for Multiple Versus Single Pregnancies

PURPOSE OF THE REVIEW

The purpose of this review was to compare physiological and metabolic changes in singleton and twin gestations and to review pregnancy outcomes with respect to current weight gain guidelines.

RECENT FINDINGS

Reviews in singleton gestations show that weight gain below the recommended guidelines has been associated with small for gestational age infants (less than the 10th percentile) which place these infants at increased risk for neonatal morbidities. Observational studies have shown that adequate and excessive gestational weight gain in twin gestations has been associated with longer gestations and less preterm birth along with increased birth weight at delivery. Weight gain in pregnancy has been identified as a factor that affects both maternal and infant health outcomes in singleton and twin gestations. There is a larger body of research examining these effects in singleton gestations than twin gestations; however, in both groups, the data remain mostly observational and retrospective. Thus far, the research supports the Institute of Medicine recommended weight gain guidelines in singleton and twin gestations for women with normal BMI, but future research should be directed toward underweight and overweight women and the long-term outcomes in all mothers and their offspring.

Contribution of Gestational Weight Gain on Maternal Glucose Metabolism in Women with GDM and Normal Glucose Tolerance

Context

Efforts to decrease the risk of developing metabolic complications of pregnancy such as gestational diabetes (GDM) through lifestyle intervention (decreasing excessive gestational weight gain (GWG)) during pregnancy have met with limited success.

Objective

The purpose of this study was to determine the relationship between the longitudinal changes in weight/body composition and insulin sensitivity and response in women with normal glucose tolerance (NGT) and those who developed GDM.

Design

We conducted a secondary analysis of a prospective cohort developed before conception and again at 34 to 36 weeks gestation. A total of 29 NGT and 17 GDM women were evaluated for longitudinal changes in insulin sensitivity/response using the hyperinsulinemic-euglycemic clamp and an IV-glucose tolerance test. Body composition was estimated using hydrodensitometry. Both absolute change (Δ) and relative change (%Δ) between these 2 time points were calculated. We performed simple and multiple linear regression analysis to assess the relationship between GWG and measures of glucose metabolism, ie, insulin sensitivity and response.

Results

Based on the primary study design there was no significant difference in clinical characteristics between women with NGT and those developing GDM. Prior to pregnancy, women who developed GDM had lower insulin sensitivity levels (P = 0.01) compared with NGT women. Absolute change and %Δ in insulin sensitivity/insulin response and body weight/body composition were not significantly different between NGT and GDM women. Changes in body weight contributed to only 9% of the Δ in insulin sensitivity both in women developing GDM and NGT women.

Conclusions

These data suggest that other factors—such as maternal pre-pregnancy insulin sensitivity and placental derived factors affecting insulin sensitivity—rather than maternal GWG account for the changes in glucose metabolism during human pregnancy.

Body composition helps: Differences in energy expenditure between pregnant and nonpregnant females

OBJECTIVES

Human pregnancy is associated with important physiological changes that usually increase energetic requirements. However, great variability exists in the costs and mechanisms required to bear pregnancy. Since body mass (BM) and composition are modified during gestation, it is of great interest to compare the influence of BM on energy expenditure (EE) in pregnant and nonpregnant females.

METHODS

BM, body composition, and EE of 77 volunteers (35 pregnant and 42 nonpregnant females) were measured. The pregnant volunteers completed two measurement rounds at 28 and 32 gestation weeks. Differences on the measured parameters were sought, and comparison of regression lines was computed to test how BM affected the EE of the volunteers.

RESULTS

BM and body composition parameters are significantly higher in pregnant females, but EE is not statistically different. Pregnant females have a larger percentage of fat mass, but lower percentage of fat-free mass (FFM). The EE per kg of FFM is similar in both groups. Comparison of regression lines shows that pregnancy does not change the relationship between BM and EE, but for similar BM pregnant females expend less energy than nonpregnant females.

CONCLUSIONS

We propose that their larger percentage of passive body tissues is the reason why pregnant females expend less energy than nonpregnant females of similar BM, without changing the scaling of EE on BM. Thus, pregnancy could not be as energetically constraining as usually assumed, with important consequences for human reproductive ecology.

Time to change weight gain recommendations for pregnant women with obesity

Obesity during pregnancy is a major health problem in the United States. In this issue of the JCI, Most et al. fill an important gap in our understanding of energy homeostasis in pregnancy. The researchers measured energy intake, energy expenditure, and body composition in obese pregnant women. They demonstrated that energy intake need not increase in order for obese women to gain the recommended amounts of weight during pregnancy. Additionally, all of the gestational weight gain scenarios (inadequate, recommended, or excess) resulted in similar maternal and fetal perinatal outcomes. This evidence should guide new recommendations on this important topic.

Resting Energy Expenditure Relationship with Macronutrients and Gestational Weight Gain: A Pilot Study

Resting energy expenditure (REE) comprises 60% of total energy expenditure and variations may be associated with gestational weight gain (GWG) or maternal diet. The objective of this study was to examine the impact of metabolic tracking on GWG and the association with maternal macronutrients. Pregnant women aged 29.8 ± 4.9 years (78.6% non-Hispanic, White) with gestational age (GA) < 17 week were randomized to Breezing™ (n = 16) or control (n = 12) groups for 13 weeks. REE by Breezing™ indirect calorimetry, anthropometrics and dietary intake were collected every two weeks. Early (14–21 weeks), late (21–28 weeks), and overall (14–28 weeks) changes in macronutrients and GWG were calculated. The Breezing™ group had a significantly greater rate of GWG [F (1,23) = 6.8, p = 0.02] in the latter half of the second trimester. Late (−155.3 ± 309.2 vs. 207.1 ± 416.5 kcal, p = 0.01) and overall (−143.8 ± 339.2 vs. 191.8 ± 422.2 kcal, p = 0.03) changes in energy consumption were significantly different between Breezing™ and control groups, respectively. Early changes in REE were positively correlated with overall changes in carbohydrates (r = 0.58, p = 0.02). Regular metabolism tracking alone did not have an impact on GWG. Early shifts in REE might impact GWG later in pregnancy. Investigation in a larger population from preconception through postpartum is needed.

The effect of cisatracurium infusion on the energy expenditure of critically ill patients: an observational cohort study

Background

Both overfeeding and underfeeding of intensive care unit (ICU) patients are associated with worse outcomes. A reliable estimation of the energy expenditure (EE) of ICU patients may help to avoid these phenomena. Several factors that influence EE have been studied previously. However, the effect of neuromuscular blocking agents on EE, which conceptually would lower EE, has not been extensively investigated.

Methods

We studied a cohort of adult critically ill patients requiring invasive mechanical ventilation and treatment with continuous infusion of cisatracurium for at least 12 h. The study aimed to quantify the effect of cisatracurium infusion on EE (primary endpoint). EE was estimated based on ventilator-derived VCO₂ (EE in kcal/day = VCO₂ × 8.19). A subgroup analysis of septic and non-septic patients was performed. Furthermore, the effects of body temperature and sepsis on EE were evaluated. A secondary endpoint was hypercaloric feeding (> 110% of EE) after cisatracurium infusion.

Results

In total, 122 patients were included. Mean EE before cisatracurium infusion was 1974 kcal/day and 1888 kcal/day after cisatracurium infusion. Multivariable analysis showed a significantly lower EE after cisatracurium infusion (MD − 132.0 kcal (95% CI − 212.0 to − 52.0; p = 0.001) in all patients. This difference was statistically significant in both sepsis and non-sepsis patients (p = 0.036 and p = 0.011). Non-sepsis patients had lower EE than sepsis patients (MD − 120.6 kcal; 95% CI − 200.5 to − 40.8, p = 0.003). Body temperature and EE were positively correlated (Spearman’s rho = 0.486, p < 0.001). Hypercaloric feeding was observed in 7 patients.

Conclusions

Our data suggest that continuous infusion of cisatracurium in mechanically ventilated ICU patients is associated with a significant reduction in EE, although the magnitude of the effect is small. Sepsis and higher body temperature are associated with increased EE. Cisatracurium infusion is associated with overfeeding in only a minority of patients and therefore, in most patients, no reductions in caloric prescription are necessary.

Energy Intake Requirements in Pregnancy

Energy intake requirements in pregnancy match the demands of resting metabolism, physical activity, and tissue growth. Energy balance in pregnancy is, therefore, defined as energy intake equal to energy expenditure plus energy storage. A detailed understanding of these components and their changes throughout gestation can inform energy intake recommendations for minimizing the risk of poor pregnancy outcomes. Energy expenditure is the sum of resting and physical activity-related expenditure. Resting metabolic rate increases during pregnancy as a result of increased body mass, pregnancy-associated physiological changes, i.e., cardiac output, and the growing fetus. Physical activity is extremely variable between women and may change over the course of pregnancy. The requirement for energy storage depends on maternal pregravid body size. For optimal pregnancy outcomes, women with low body weight require more fat mass accumulation than women with obesity, who do not require to accumulate fat mass at all. Given the high energy density of fat mass, these differences affect energy intake requirements for a healthy pregnancy greatly. In contrast, the energy stored in fetal and placental tissues is comparable between all women and have small impact on energy requirements. Different prediction equations have been developed to quantify energy intake requirements and we provide a brief review of the strengths and weaknesses and discuss their application for healthy management of weight gain in pregnant women.

Reprint of characterizing gestational weight gain in a cohort of indigenous Australian women

OBJECTIVE

to determine the adequacy of gestational weight gain for a cohort of Indigenous Australian women and investigate whether it is associated with pre-pregnancy body mass index.

DESIGN

analysis of observational data collected from a longitudinal cohort study that follows Indigenous Australian women through pregnancy.

SETTING

women recruited through antenatal clinics in regional and remote towns in NSW, Australia to the Gomeroi gaaynggal program.

PARTICIPANTS

110 pregnant women who either identified as being an Indigenous Australian or as carrying an Indigenous child.

MEASUREMENTS AND FINDINGS

measurements included weight and height, self-reported pre-pregnancy weight and smoking status, parity and health conditions that may contribute to gestational weight gain, such as hypertensive or diabetic disorders. Compared to the 2009 Institute of Medicine recommendations for gestational weight gain and based on pre-pregnancy body mass index, the rate of adequate gestational weight gain in this cohort was low (26%). 33% of women had inadequate weight gain and 41% had excessive weight gain. The highest rate of excessive gestational weight gain was found in overweight women (65%), with rates of 39% and 31% found in healthy and obese (all classes) categories, respectively. Parity (coefficient 4.2, p < 0.01) and hypertension (coefficient 4.3, p = 0.049) were found to be significantly associated with gestational weight gain in mixed model linear regression.

CONCLUSIONS

few women gained adequate gestational weight gain in this study. Culturally acceptable ways of addressing this issue are needed for this group of women, as inadequate and excessive rates of gestational weight gain have health implications for women and their offspring.

IMPLICATIONS FOR PRACTICE

a systematic approach to addressing gestational weight gain within antenatal care is required, including asking about diet and exercise, for all women identifying as Indigenous Australian.

Energy Expenditure in Pregnant Women with Obesity Does Not Support Energy Intake Recommendations

OBJECTIVE

This study aimed to identify factors that may predispose women to excess gestational weight gain (GWG).

METHODS

Seventy-two healthy women with obesity (30 class I, 24 class II, 18 class III) expecting a singleton pregnancy were studied at 13 to 16 weeks gestation. Energy expenditure (EE) was measured during sleep (SleepEE, average EE from 0200-0500 hours) in a whole-room calorimeter, and total daily EE (TDEE) over 7 days using doubly labeled water. Glucose, insulin, thyroid hormones, and catecholamines were measured.

RESULTS

Body composition explained 70% variability in SleepEE, and SleepEE accounted for 67% to 73% of TDEE. Though there was no evidence of consistent low metabolism, there was considerable variability. Low SleepEE was associated with insulin resistance and low triiodothyronine concentrations (both P = 0.01). Physical activity level was 1.47 ± 0.02. For women with SleepEE within 100 kcal/d of their predicted EE, TDEE was significantly less than the estimate (2,530 ± 91 vs. 2,939 kcal/d; P < 0.001) provided from the most recent gestational energy requirement model.

CONCLUSIONS

Pregnant women with obesity are inactive, possibly predisposing them to excess GWG. Current energy requirement models overestimate activity and may promote excess GWG in women with obesity. Furthermore, the observed large interindividual variability in basal metabolism may be important to consider when assessing the risk for excess GWG.

Amant M, Beyl RA, Ravussin E, Redman LM. Propensity for adverse pregnancy outcomes in African-American women may be explained by low energy expenditure in early pregnancy

Background

African-American (AA) women have poorer pregnancy outcomes, and studies in nonpregnant women suggest a different etiology of weight gain in AA compared with white women. We hypothesized that physiologic factors such as low energy expenditure and physical activity would be present in AA compared with white women in pregnancy.

Objective

We aimed to identify physiologic risk factors for disordered energy balance in AA and white women early in pregnancy.

Design

This was a cross-sectional study in 66 pregnant women with obesity, between 14 and 16 wk of gestation. Energy intake was calculated using the intake-balance method. Energy expenditure was measured in free-living conditions [total daily energy expenditure (TDEE)] over 7 d with the use of doubly labelled water and during sleep [sleeping EE (SleepEE)] in a room calorimeter. Body composition was measured by air displacement plethysmography and physical activity by accelerometers. Markers of metabolic health were obtained from fasting blood and urine.

Results

AA (n = 34) and white (n = 32) women were comparable in age (mean ± SEM: 27.7 ± 0.6 y), enrollment body mass index [mean ± SEM (in kg/m2): 36.9 ± 0.7], and body fat (mean ± SEM: 45.0% ± 0.6%). AA women had more fat-free mass (P = 0.01) and tended to be more insulin-resistant (homeostasis model assessment of insulin resistance, P = 0.06). Energy intake was significantly lower in AA than in white women (2499 ± 76 compared with 2769 ± 58 kcal/d, P = 0.001), although absolute TDEE was comparable (AA: 2590 ± 77 kcal/d; white: 2711 ± 56 kcal/d; P = 0.21). After adjusting for body composition, TDEE was significantly lower in AA women (-231 ± 74 kcal/d, P = 0.003), as was SleepEE (-81 ± 37 kcal/d, P = 0.03). Physical activity, substrate oxidation, and metabolic biomarkers (triiodothyronine and thyroxine concentrations, catecholamine excretion) were not significantly different between groups.

Conclusions

Body mass-adjusted energy expenditure is significantly lower in AA than in white pregnant women. Energy intake recommendations for pregnancy do not consider this difference and may therefore overestimate energy requirements in AA women. This may lead to unintentional overeating and contribute to the disparity of excess gestational weight gain and postpartum weight retention that is more prevalent in AA women. This trial was registered at clinicaltrials.gov as NCT01954342.

Characterizing gestational weight gain in a cohort of Indigenous Australian women

OBJECTIVE

to determine the adequacy of gestational weight gain for a cohort of Indigenous Australian women and investigate whether it is associated with pre-pregnancy body mass index.

DESIGN

analysis of observational data collected from a longitudinal cohort study that follows Indigenous Australian women through pregnancy.

SETTING

women recruited through antenatal clinics in regional and remote towns in NSW, Australia to the Gomeroi gaaynggal program.

PARTICIPANTS

110 pregnant women who either identified as being an Indigenous Australian or as carrying an Indigenous child.

MEASUREMENTS AND FINDINGS

measurements included weight and height, self-reported pre-pregnancy weight and smoking status, parity and health conditions that may contribute to gestational weight gain, such as hypertensive or diabetic disorders. Compared to the 2009 Institute of Medicine recommendations for gestational weight gain and based on prepregnancy body mass index, the rate of adequate gestational weight gain in this cohort was very low (15%). 32% of women had inadequate weight gain and 54% had excessive weight gain. The highest rate of excessive gestational weight gain was found in overweight women (74%), with rates of 48% and 50% found in healthy and obese (all classes) categories, respectively. Parity (coefficient 4.5, p<0.01) and hypertension (coefficient 4.8, p = 0.04) were found to be significantly associated with gestational weight gain in mixed model linear regression.

CONCLUSIONS

few women gained adequate gestational weight gain in this study. Culturally acceptable ways of addressing this issue are needed for this group of women, as inadequate and excessive rates of gestational weight gain have health implications for women and their offspring.

IMPLICATIONS FOR PRACTICE

a systematic approach to addressing gestational weight gain within antenatal care is required, including asking about diet and exercise, for all women identifying as Indigenous Australian.