The relationship between moderate-to-vigorous intensity physical activity and insulin resistance, insulin-like growth factor (IGF-1)-system 1, leptin and weight change in healthy women during pregnancy and after delivery

Evidence-based trends and association between symptom disturbance and physical activity among pregnant women: A longitudinal study

BACKGROUND

Women usually decrease their physical activity (PA) after becoming pregnant. The change in PA may influence their symptom distress (SD). The changes and correlations between SD and PA throughout pregnancy remain unclear.

AIMS

The aims of this study were to describe PA and SD trajectories across all three trimesters and examine their correlations during pregnancy.

METHODS

A repeated-measure longitudinal study with convenience sampling at a hospital in Northern Taiwan was performed. Participants were recruited at 8-16 weeks of gestation, and two follow-up visits were performed at 24-28 weeks of gestation (second trimester) and after 36 weeks of gestation (third trimester). A total of 225 participants completed the study. The participants completed the Pregnancy Physical Activity Questionnaire (PPAQ) and Pregnancy-related Symptom Disturbance Scale (PSD), and sociodemographic and prenatal variables were recorded.

RESULTS

Throughout pregnancy, SD decreased then increased, showing an overall upward trend, whereas PA showed the opposite pattern, increasing then decreasing, with an overall downward trend. Sedentary activity was positively correlated with both physical and psychological SD during the second and third trimesters. Exceeding the Institute of Medicine's recommendations for gestational weight gain, having childcare support, sport/exercise-type, and light-intensity PA were negatively associated with the physical and psychological SD, while a history of miscarriage and sedentary-intensity PA were positively associated with the physical and psychological SD.

LINKING EVIDENCE TO ACTION

While several factors, including light-intensity PA, were found negatively associated with the physical and psychological SD, sedentary-intensity PA were positively associated with the physical and psychological SD, our findings shed light on future intervention strategies to relieve SD and decrease sedentary behavior among pregnant women.

Mentha cordifolia Leaf Extract Improves Hepatic Glucose and Lipid Metabolism in Obese Mice Fed with High-Fat Diet

Mentha cordifolia (MC) is a popular herb used to flavor food in Thailand that exhibits several biological effects. The present study aimed to determine the role of MC in regulating glucose and lipid metabolism in mice fed a high-fat diet (HFD). ICR obese mice were fed an HFD (45 kcal% lard fat) for 12 weeks, with MC (100 and 200 mg/kg/d) treatment from Week 7. After treatment with MC for 6 weeks, mice showed significantly lower rates of hyperglycemia, hyperinsulinemia, hyperleptinemia, and hyperlipidemia, and increased amounts of serum adiponectin. Furthermore, in mice treated with MC, serum interleukin-6 and tumor necrosis factor alpha were significantly inhibited and liver histology results showed decreased lipid accumulation and liver triglyceride content vs. untreated mice. In addition, MC treatment was associated with smaller fat cells and lower gene expression of liver sterol regulatory element binding protein 1c, acetyl-CoA carboxylase, and fatty acid synthase. However, MC treatment was associated with higher carnitine palmitoyltransferase 1a gene expression and significantly higher rates of adenosine monophosphate-activated protein kinase (AMPK) phosphorylation in liver, but lower levels of phosphoenolpyruvate carboxykinase and glucose-6-phosphatase. These results indicate MC regulates glucose and lipid metabolism in a HFD-induced obese mouse model, possibly via activation of AMPK signaling pathway.

Physical activity during pregnancy and association with changes in fat mass and adipokines in women of normal-weight or with obesity

Adipose tissue and adipokine concentrations change markedly during pregnancy, but the effects of physical activity on these changes are rarely studied. We aimed to assess physical activity levels in pregnant women of normal-weight (NW) or with obesity (OB), and to determine the relation with changes in fat mass and adipokines. In each trimester, pregnant women (136 NW, 51 OB) were interviewed about their physical activity and had their body composition, leptin, soluble leptin receptor (sOB-R) and adiponectin determined. NW reported higher activity and more aerobic exercise than OB during early pregnancy. Both groups maintained training frequency but reduced overall activity as pregnancy progressed. NW women reporting aerobic and/or resistance exercise and OB women reporting aerobic exercise had greater sOB-R increases (independent of BMI or gestational weight gain). In NW, exercise also associated with lower fat mass and leptin increases. Higher activity levels associated with lower gestational weight gain in both groups. The relationship between physical activity and adiponectin differed between NW and OB. Maternal exercise may partly mediate its beneficial effects through regulation of leptin bioavailability, by enhancing pregnancy-induced increases in sOB-R. This could be of particular importance in OB with pre-gestational hyperleptinemia and leptin resistance.

GATA-3 as a Potential Therapeutic Target for Insulin Resistance and Type 2 Diabetes Mellitus

Impaired adipogenesis plays an important role in the development of obesity-associated insulin resistance and type 2 diabetes as it leads to ectopic fat deposition. The anti-adipogenic transcription factor GATA-3 was identified as one of the potential molecular targets responsible for the impairment of adipogenesis. The expression of GATA-3 is higher in insulinresistant obese individuals compared to BMI-matched insulin-sensitive counterparts. Adipose tissue inflammation is a crucial mediator of this process. Hyperglycemia mediates the activation of the immune system, partially through upregulation of GATA- 3, causing exacerbation of the inflammatory state associated with obesity. This review discusses the evidence supporting the inhibition of GATA-3 as a useful therapeutic strategy in obesity-associated insulin resistance and type 2 diabetes, through up-regulation adipogenesis and amelioration of the immune response.

The impact of body mass index and sociodemographic factors on moderate-to-vigorous physical activity and sedentary behaviors of women with young children: A cross-sectional examination

Objectives:

Moderate-to-vigorous physical activity provides multiple benefits to women after childbirth. To achieve these benefits, the recommendation that adults obtain, 150 min of moderate-to-vigorous physical activity per week and reduce sedentary behaviors, also applies to women in the post-partum phase of the life span. However, research examining the moderate-to-vigorous physical activity and sedentary behaviors of women with young children (0–2 years) is limited. A greater understanding of these behaviors from a nationally representative sample is needed. Therefore, the primary objective of this study was to determine the levels of moderate-to-vigorous physical activity and sedentary behaviors of a nationally representative sample of women with young children within the United States. A secondary objective was to examine the influence of body mass index and sociodemographic factors on these behaviors.

Methods:

Cross-sectional data from four cycles of the National Health and Nutrition Examination Survey (2007–2008, 2009–2010, 2011–2012, and 2013–2014) were used for analysis. Descriptive statistics were calculated and a generalized linear model was used to investigate associations between mean minutes of moderate-to-vigorous physical activity, sedentary activity, body mass index, and sociodemographic variables.

Discussion:

Women with young children (n = 477) obtained 634 min in moderate-to-vigorous physical activity per week and this was positively associated with having a higher income (p < 0.001) and the number of children in the home (p < 0.001). In total, 62% of women were meeting the World Health Organization guidelines for aerobic activity. Lower odds of achieving guidelines was associated with being Black (p = 0.004), Mexican American (p = 0.009), or married (p = 0.042) compared with being White or not married. Finally, women accumulated ~5 h of sedentary activity per day, with higher levels associated with race (p = 0.005), education (p = 0.022), and number of children within the home (p < 0.001). Research efforts should continue to focus on strategies to help non-adhering women with young children achieve the physical activity recommendations and reduce time spent in sedentary behaviors.

Maternal Serum and Breast Milk Adiponectin: The Association with Infant Adiposity Development

The prevalence of childhood obesity is increasing at an alarming rate in Malaysia. Metabolic changes during pregnancy are critical to the development of infant adiposity, due to imbalanced adipokines production. Hence, we aimed to investigate the association of maternal serum and breast milk adipokines with infant adiposity development. The study was conducted from April 2010 until December 2012. A total of 155 healthy pregnant mothers aged 19 to 40 years were recruited during the first and second trimester in Kelantan, Malaysia. Data consisted of maternal sociodemographic details, anthropometry and clinical biochemistry analysis; and the infant’s anthropometry and feeding patterns. Maternal fasting serum and breast milk samples were analysed for adiponectin and leptin levels. Data collection was performed in the second and third trimester of pregnancy, and continued with follow-up visits at birth, two, six, and 12 months postpartum. Multiple linear regression (MLR) analyses were performed to examine the associations between maternal serum and breast milk adiponectin and leptin and infant adiposity development. MLR models showed that, in the first year, as maternal serum and breast milk adiponectin increased, infant weight, BMI-for-age Z scores and abdominal circumference significantly decreased (p < 0.05). Maternal serum and/or breast milk adiponectin was associated with first-year infant adiposity development.

A vicious circle between insulin resistance and inflammation in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) comprises a spectrum of diseases, including simple steatosis, nonalcoholic steatohepatitis (NASH), liver cirrhosis and hepatocellular carcinoma. Lipotoxicity, insulin resistance (IR) and inflammation are involved in the disease process. Lipotoxicity promotes inflammation and IR, which in turn, increase adipocyte lipolysis and exacerbates lipotoxicity. Furthermore, IR and inflammation form a vicious circle, with each condition promoting the other and accelerating the development of NAFLD in the presence of lipotoxicity. As an integrator of inflammatory pathway networks, nuclear factor-kappa B (NF-κB) regulates expression of pro-inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6), and anti-inflammatory cytokines, such as adiponectin in NAFLD. In this review, the relationships between lipotoxicity, IR and inflammation in NAFLD are discussed, with particular emphasis on the inflammatory pathways.

Exercise during pregnancy and its impact on mothers and offspring in humans and mice

Exercise during pregnancy has beneficial effects on maternal and offspring’s health in humans and mice. The underlying mechanisms remain unclear. This comparative study aimed to determine the long-term effects of an exercise program on metabolism, weight gain, body composition and changes in hormones [insulin, leptin, brain-derived neurotrophic factor (BDNF)]. Pregnant women (n=34) and mouse dams (n=44) were subjected to an exercise program compared with matched controls (period I). Follow-up in the offspring was performed over 6 months in humans, corresponding to postnatal day (P) 21 in mice (period II). Half of the mouse offspring was challenged with a high-fat diet (HFD) for 6 weeks between P70 and P112 (period III). In period I, exercise during pregnancy led to 6% lower fat content, 40% lower leptin levels and an increase of 50% BDNF levels in humans compared with controls, which was not observed in mice. After period II in humans and mice, offspring body weight did not differ from that of the controls. Further differences were observed in period III. Offspring of exercising mouse dams had significantly lower fat mass and leptin levels compared with controls. In addition, at P112, BDNF levels in offspring were significantly higher from exercising mothers while this effect was completely blunted by HFD feeding. In this study, we found comparable effects on maternal and offspring’s weight gain in humans and mice but different effects in insulin, leptin and BDNF. The long-term potential protective effects of exercise on biomarkers should be examined in human studies.

Mechanisms Linking Inflammation to Insulin Resistance

Obesity is now widespread around the world. Obesity-associated chronic low-grade inflammation is responsible for the decrease of insulin sensitivity, which makes obesity a major risk factor for insulin resistance and related diseases such as type 2 diabetes mellitus and metabolic syndromes. The state of low-grade inflammation is caused by overnutrition which leads to lipid accumulation in adipocytes. Obesity might increase the expression of some inflammatory cytokines and activate several signaling pathways, both of which are involved in the pathogenesis of insulin resistance by interfering with insulin signaling and action. It has been suggested that specific factors and signaling pathways are often correlated with each other; therefore, both of the fluctuation of cytokines and the status of relevant signaling pathways should be considered during studies analyzing inflammation-related insulin resistance. In this paper, we discuss how these factors and signaling pathways contribute to insulin resistance and the therapeutic promise targeting inflammation in insulin resistance based on the latest experimental studies.