Biological changes in the pregnancy-postpartum period and subsequent cardiometabolic risk-UPSIDE MOMS: A research protocol

Maternal BMI changes from the prepregnancy to postpartum period are associated with postpartum cardiometabolic risk factors: a longitudinal study

PURPOSE

This study aimed at investigating the associations between the total body mass index (BMI) change at 3 or 4 years postpartum compared to the prepregnancy and cardiometabolic risk factors.

METHODS

This longitudinal study included 1305 participants. Based on the total postpartum BMI changes, they were divided into < 0 units, 0-1.7 units, and > 1.7 units groups using the interquartile range. Multiple linear regression models were used to analyze the associations.

RESULTS

Compared to the reference group, there was a progressive increase in the βcoefficient (βcoef) of homeostasis model assessment of insulin resistance (HOMA-IR) of cardiometabolic risk in the following groups: the '0-1.7 units' group with the 'overweight traj' [βcoef 0.33; 95% confidence intervals (CI) 0.22, 0.44)] or the 'obesity traj' [0.66; (0.45, 0.88)] and the '> 1.7 units' group with the 'normal traj' [0.33; (0.22, 0.44)], the 'overweight traj' [0.54; (0.41, 0.67)] or the 'obesity traj' [0.97; (0.79, 1.15)]. The same increasing trend of βcoef was also found in DBP, FPG, LDL, WHR, BF%. However, the '< 0 units' group with the 'low traj' [0.13; (0.06, 0.21)] and the '0-1.7 units' group with the 'low traj' [0.08; (0.03, 0.13)] had higher high-density lipoprotein cholesterol (HDL-C) level than the reference group.

CONCLUSION

Women with a postpartum BMI gain > 1.7 units are positively associated with cardiometabolic risk factors, especially for those in the 'obesity traj' or 'traj D'. Conversely, women with a postpartum BMI loss > 0 units have negative association with cardiometabolic risk factors, especially for those in the 'low traj' or 'traj B'.

Association between sex steroid hormones and subsequent hyperglycemia during pregnancy

Objective

Sex steroid hormones may play a role in insulin resistance and glucose dysregulation. However, evidence regarding associations between early-pregnancy sex steroid hormones and hyperglycemia during pregnancy is limited. The primary objective of this study was to assess the relationships between first trimester sex steroid hormones and the subsequent development of hyperglycemia during pregnancy; with secondary evaluation of sex steroid hormones levels in mid-late pregnancy, concurrent with and subsequent to diagnosis of gestational diabetes.

Methods

Retrospective analysis of a prospective pregnancy cohort study was conducted. Medically low-risk participants with no known major endocrine disorders were recruited in the first trimester of pregnancy (n=319). Sex steroid hormones in each trimester, including total testosterone, free testosterone, estrone, estradiol, and estriol, were assessed using high-performance liquid chromatography and tandem mass spectrometry. Glucose levels of the 1-hour oral glucose tolerance test and gestational diabetes diagnosis were abstracted from medical records. Multivariable linear regression models were fitted to assess the associations of individual first trimester sex steroids and glucose levels.

Results

In adjusted models, first trimester total testosterone (β=5.24, 95% CI: 0.01, 10.46, p=0.05) and free testosterone (β=5.98, 95% CI: 0.97, 10.98, p=0.02) were positively associated with subsequent glucose concentrations and gestational diabetes diagnosis (total testosterone: OR=3.63, 95% CI: 1.50, 8.78; free testosterone: OR=3.69; 95% CI: 1.56, 8.73). First trimester estrone was also positively associated with gestational diabetes (OR=3.66, 95% CI: 1.56, 8.55). In mid-late pregnancy, pregnant people with gestational diabetes had lower total testosterone levels (β=-0.19, 95% CI: -0.36, -0.02) after adjustment for first trimester total testosterone.

Conclusion

Early-pregnancy sex steroid hormones, including total testosterone, free testosterone, and estrone, were positively associated with glucose levels and gestational diabetes in mid-late pregnancy. These hormones may serve as early predictors of gestational diabetes in combination with other risk factors.

Per- and polyfluoroalkyl substances, gestational weight gain, postpartum weight retention and body composition in the UPSIDE cohort

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS) are synthetic chemicals found in drinking water and consumer products, resulting in ubiquitous human exposure. PFAS have been linked to endocrine disruption and altered weight gain across the lifespan. A limited and inconsistent body of research suggests PFAS may impact gestational weight gain (GWG) and postpartum body mass index (BMI), which are important predictors of overall infant and maternal health, respectively.

METHODS

In the Understanding Pregnancy Signals and Infant Development (UPSIDE/UPSIDE-MOMs) study (n = 243; Rochester, NY), we examined second trimester serum PFAS (PFOS: perfluorooctanesulfonic acid, PFOA: perfluorooctanoic acid, PFNA: perfluorononanoic acid, PFHxS: perfluorohexanesulfonic acid, PFDA: perfluorodecanoic acid) in relation to GWG (kg, and weekly rate of gain) and in the postpartum, weight retention (PPWR (kg) and total body fat percentage (measured by bioelectrical impedance)). We fit multivariable linear regression models examining these outcomes in relation to log-transformed PFAS in the whole cohort as well as stratified by maternal pre-pregnancy BMI (< 25 vs. =  > 25 kg/m2), adjusting for demographics and lifestyle factors. We used weighted quantile sum regression to find the combined influence of the 5 PFAS on GWG, PPWR, and body fat percentage.

RESULTS

PFOA and PFHxS were inversely associated with total GWG (PFOA: ß = -1.54 kg, 95%CI: -2.79, -0.30; rate ß = -0.05 kg/week, 95%CI: -0.09, -0.01; PFHxS: ß = -1.59 kg, 95%CI: -3.39, 0.21; rate ß = -0.05 kg/week, 95%CI: -0.11, 0.01) and PPWR at 6 and 12 months (PFOA 6 months: ß = -2.39 kg, 95%CI: -4.17, -0.61; 12 months: ß = -4.02 kg, 95%CI: -6.58, -1.46; PFHxS 6 months: ß = -2.94 kg, 95%CI: -5.52, -0.35; 12 months: ß = -5.13 kg, 95%CI: -8.34, -1.93). PFOA was additionally associated with lower body fat percentage at 6 and 12 months (ß = -1.75, 95%CI: -3.17, -0.32; ß = -1.64, 95%CI: -3.43, 0.16, respectively) with stronger associations observed in participants with higher pre-pregnancy BMI. The PFAS mixture was inversely associated with weight retention at 12 months (ß = -2.030, 95%CI: -3.486, -0.573) amongst all participants.

CONCLUSION

PFAS, in particular PFOA and PFHxS, in pregnancy are associated with altered patterns of GWG and postpartum adiposity with potential implications for fetal development and long-term maternal cardiometabolic health.

Relationships among Postpartum Weight Retention, Stress, and Disinhibited Eating: A Scoping Review

Postpartum weight retention (PPWR) is a significant contributor to maternal cardiometabolic disease risk. The transition to motherhood is a stressful time period in which women report consuming food to cope, an eating behavior that is associated with PPWR. In this scoping review, we identified original research and review articles published since 2010 that examined relationships among PPWR, maternal stress, and disinhibited eating. In total, 16 articles met the inclusion criteria. Findings were inconsistent related to PPWR and stress. PPWR and disinhibited eating were not significantly correlated; however, disinhibition scores were higher during the postpartum period compared to prenatally. Stress and disinhibited eating were directly correlated in 4 studies. Our findings suggest these concepts, particularly disinhibited eating, have not been robustly examined during the postpartum period. Additionally, instruments used to measure maternal stress vary widely and should be further studied and refined.

Protracted Impairment of Maternal Metabolic Health in Mouse Dams Following Pregnancy Exposure to a Mixture of Low Dose Endocrine-Disrupting Chemicals, a Pilot Study

Pregnancy, a period of increased metabolic demands coordinated by fluctuating steroid hormones, is an understudied critical window of disease susceptibility for later-life maternal metabolic health. Epidemiological studies have identified associations between exposures to various endocrine-disrupting chemicals (EDCs) with an increased risk for metabolic syndrome, obesity, and diabetes. Whether such adverse outcomes would be heightened by concurrent exposures to multiple EDCs during pregnancy, consistent with the reality that human exposures are to EDC mixtures, was examined in the current pilot study. Mouse dams were orally exposed to relatively low doses of four EDCs: (atrazine (10 mg/kg), bisphenol-A (50 µg/kg), perfluorooctanoic acid (0.1 mg/kg), 2,3,7,8-tetrachlorodibenzo-p-dioxin (0.036 µg/kg)), or the combination (MIX), from gestational day 7 until birth or for an equivalent 12 days in non-pregnant females. Glucose intolerance, serum lipids, weight, and visceral adiposity were assessed six months later. MIX-exposed dams exhibited hyperglycemia with a persistent elevation in blood glucose two hours after glucose administration in a glucose tolerance test, whereas no such effects were observed in MIX-exposed non-pregnant females. Correspondingly, MIX dams showed elevated serum low-density lipoprotein (LDL). There were no statistically significant differences in weight or visceral adipose; MIX dams showed an average visceral adipose volume to body volume ratio of 0.09, while the vehicle dams had an average ratio of 0.07. Collectively, these findings provide biological plausibility for the epidemiological associations observed between EDC exposures during pregnancy and subsequent maternal metabolic dyshomeostasis, and proof of concept data that highlight the importance of considering complex EDC mixtures based of off common health outcomes, e.g., for increased risk for later-life maternal metabolic effects following pregnancy.