The Exercise-Induced Irisin Is Associated with Improved Levels of Glucose Homeostasis Markers in Pregnant Women Participating in 8-Week Prenatal Group Fitness Program: A Pilot Study

Physical exercise for a healthy pregnancy: the role of placentokines and exerkines

Complications such as diabetes and preeclampsia can occur during pregnancy. Moderate-intensity exercise can prevent such complications by releasing placentokines and exerkines, such as apelin, adiponectin, leptin, irisin, and chemerin. Exercise and apelin increase thermogenesis and glucose uptake in pregnancy by activating AMPK, PI3K, PGC-1α, AKT1, UCP3, and sarcolipin. Exercise increases apelin levels to reduce preeclampsia symptoms by increasing eNOS, NO, placental growth factor (PlGF), and VEGF and decreasing levels of fms-like tyrosine kinase 1 (sFlt-1), soluble endoglin (sEng), and oxidative stress. A negative relationship has been reported between plasma leptin and VO2peak/kg and VO2peak in women with gestational diabetes. In active women, decreases in leptin levels reduce the risk of preeclampsia by ~ 40%. Higher adiponectin levels are associated with greater physical activity and lead to increased insulin sensitivity. Increased adiponectin levels in preeclampsia and exercise counteract inflammatory and atherogenic activities while also having vascular protective effects. Exercise increases irisin levels that correlate negatively with fasting glucose, insulin concentration, and glycosylated hemoglobin levels. Irisin augments mRNA expression levels of UCP1 and cell death-inducing DNA fragmentation factor-like effector A (cidea) to cause browning of adipose tissue, increased thermogenesis, and increased energy consumption. Irisin concentrations in mothers with preeclampsia in the third trimester negatively correlate with systolic and diastolic blood pressure. Expression levels of chemerin, IL-6, and TNF-α are increased in gestational diabetes, and the increases in chemerin in late pregnancy positively correlate with the ratio of sFlt-1 to PlGF as a marker of preeclampsia. The effects of physical exercise on placentokines and exerkines in women at various stages of pregnancy remain poorly understood.

Irisin participates in the beneficial effects of exercise in preventing gestational diabetes mellitus in overweight and obese pregnant women and a mouse model

Objective

We aimed to explore whether irisin participates in the beneficial effects of exercise in preventing gestational diabetes mellitus (GDM) in overweight and obese pregnant women.

Study design

Sixty overweight and obese pregnant women each in the exercise and control groups were randomly selected from our previous randomized controlled trial. Eighteen obese model mice were generated and divided into exercise and control groups in which body weight, abdominal circumference, anal temperature, glucose tolerance test, and insulin tolerance test were recorded. The plasma irisin level, the expression of PGC-1α/FNDC5 and brown (UCP1) and beige adipose (CD137, TMEM26, and TBX-1) marker genes were detected in muscle and adipose tissue.

Results

In the human study, women in the exercise group had a significantly higher irisin level and lower insulin resistance level than those in the control group. Enhanced expression of beige adipose tissue marker genes (CD137, TMEM26, and TBX-1) in omental adipose tissue and the CD137 gene in subcutaneous adipose tissue were found in the exercise group compared to the control group. In a mouse model, body weight and abdominal circumference were decreased, while glucose homeostasis and insulin sensitivity were significantly improved, and anal temperature was elevated after exercise intervention. A significantly higher level of irisin was revealed in the exercise group after undergoing exercise treatment. The expression of the beige adipose marker genes CD137 and TBX-1 was significantly higher in the exercise group than in the control group in posterior subcutaneous adipose tissue from the inguinal area and interscapular adipose tissue respectively.

Conclusion

Our observations show that regular exercise during pregnancy can increase irisin levels, promote white fat beiging/browning, improve glucose homeostasis and enhance body energy expenditure, which may be one of the mechanisms by which exercise prevents GDM.

The role of exercise-induced myokines in promoting angiogenesis

Ischemic diseases are a major cause of mortality or disability in the clinic. Surgical or medical treatment often has poor effect on patients with tissue and organ ischemia caused by diffuse stenoses. Promoting angiogenesis is undoubtedly an effective method to improve perfusion in ischemic tissues and organs. Although many animal or clinical studies tried to use stem cell transplantation, gene therapy, or cytokines to promote angiogenesis, these methods could not be widely applied in the clinic due to their inconsistent experimental results. However, exercise rehabilitation has been written into many authoritative guidelines in the treatment of ischemic diseases. The function of exercise in promoting angiogenesis relies on the regulation of blood glucose and lipids, as well as cytokines that secreted by skeletal muscle, which are termed as myokines, during exercise. Myokines, such as interleukin-6 (IL-6), chemokine ligand (CXCL) family proteins, irisin, follistatin-like protein 1 (FSTL1), and insulin-like growth factor-1 (IGF-1), have been found to be closely related to the expression and function of angiogenesis-related factors and angiogenesis in both animal and clinical experiments, suggesting that myokines may become a new molecular target to promote angiogenesis and treat ischemic diseases. The aim of this review is to show current research progress regarding the mechanism how exercise and exercise-induced myokines promote angiogenesis. In addition, the limitation and prospect of researches on the roles of exercise-induced myokines in angiogenesis are also discussed. We hope this review could provide theoretical basis for the future mechanism studies and the development of new strategies for treating ischemic diseases.

Long-Term Effect of Exercise on Irisin Blood Levels-Systematic Review and Meta-Analysis

Physical exercise may activate a number of important biochemical processes in the human body. The aim of this systematic review and meta-analysis was to identify the long-term effect of physical activity on irisin blood levels. We searched PubMed, Scopus, and Web of Science for articles addressing the long-term effect of physical exercise on irisin blood levels. Fifty-nine articles were included in the final qualitative and quantitative syntheses. A statistically significant within-group effect of exercise on irisin blood levels was in 33 studies; out of them, the irisin level increased 23× and decreased 10×. The significant positive between-groups effect was found 11×. Furthermore, the meta-analysis indicated that physical exercise had a significant positive effect on irisin blood levels (SMD = 0.39 (95% CI 0.27–0.52)). Nevertheless, considerably high heterogeneity was found in all the analyses. This systematic review and meta-analysis indicate that physical exercise might increase irisin blood levels; however, the results of individual studies were considerably inconsistent, which questions the methodological detection of irisin by ELISA kits.

Do Physical Activity and Personality Matter for Hair Cortisol Concentration and Self-Reported Stress in Pregnancy? A Pilot Cross-Sectional Study

Background: Physical activity reduces psychosocial stress in pregnant women. Stress levels might be self-reported (psychosocial) or measured with biomarkers, one of which is hair cortisol concentration (HCC). Additionally, personality has been associated with stress and physical activity. Methods: The first aim of our study was to explore the differences in self-reported stress assessed by the Perceived Stress Scale (PSS) and in HCC with regard to physical activity level in pregnant (N = 29) and non-pregnant (N = 21) women. The second aim was to analyze the correlations among perceived stress, HCC, frequency of exercise and personality in the two groups separately. Results: There was a significant difference in frequency of exercise and self-reported stress between the two groups, with a lower level in pregnant women, but no differences in HCC and in personality were found. In the group of pregnant women, there was a significant negative correlation between HCC and frequency of exercise sessions, with the latter correlating positively with openness to experience. In the group of non-pregnant women, perceived stress negatively correlated with extraversion, agreeableness and emotional stability. HCC correlated negatively with conscientiousness. Conclusions: Our findings indicate the importance of physical activity programs dedicated to pregnant women for their life quality.

Effects of an 8-week pelvic core stability and nutrition community programme on maternal health outcomes

INTRODUCTION

Women, during the antenatal and post-partum period, report pelvic, low back pain, stress and urge urinary incontinence, colorectal dysfunction, and other co-morbidities that negatively affect health-related quality of life. Exercise and nutrition are important considerations for improving maternal health in this period.

PURPOSE

The purpose of this study was to examine the effects of a community-driven nutrition and exercise programme focused on pelvic floor and core stability, healthy nutrition, and breastfeeding counselling over an 8-week period on pelvic floor and urinary distress (UDI), prolapse and colorectal distress for antenatal and post-partum women with limited access to health care, and low socio-economic resources from a Midwestern Region of the United States.

MATERIALS AND METHODS

Purposive sample of 35 females, ages 18-44, were recruited for this prospective, preintervention to postintervention study, following ethical approval from Institutional Review Board and voluntary written consent from participants. The Health History Questionnaire, SF-36, Food Frequency Questionnaire, report of pelvic organ prolapse dysfunction (POPDI), colorectal-anal dysfunction (CRADI), and UDI as measured by the Pelvic Floor Distress Inventory (PFDI) were completed before and after intervention.

RESULTS

Thirty-five women (n = 35) 18 to 44 years old (mean age of 22.72 ± 3.45 years) completed the study. A significant difference was found from preintervention to postintervention scores means for PFDI total scores, CRADI individual scores, and UDI individual scores (p < .05). POPDI scores decreased preintervention to postintervention but were not significant. A significant improvement in healthy nutrition and breastfeeding postintervention was also found (z = 3.21, p = .001). Further analysis showed significant, but weak, correlation between parity and POPDI (r = .366, p = .033); between parity and UDI (r = .384, p = .03); and between parity and PFDI (r = .419, p = .014).

DISCUSSION

Our study found a significant reduction in pelvic floor dysfunction, urinary, and colorectal-anal distress symptoms and improvement in breastfeeding and healthy nutrition following an 8-week community-driven nutrition and exercise programme focused on pelvic floor and core stability, healthy nutrition, and breastfeeding counselling.

High-Low Impact Exercise Program Including Pelvic Floor Muscle Exercises Improves Pelvic Floor Muscle Function in Healthy Pregnant Women - A Randomized Control Trial

Background: Pregnancy and high-impact activity are considered as risk factors for pelvic floor dysfunctions, including urinary incontinence.

Aim: To investigate whether a structured exercise program, including high- and low-impact aerobics and supported by pelvic floor muscle exercises, improves the neuromuscular activity of the pelvic floor and does not reduce the quality of life in terms of urinary incontinence in healthy pregnant women.

Methods: This was a randomized control trial among 97 Caucasian healthy nulliparas in uncomplicated pregnancies (age 30 ± 4 years, 21 ± 5 weeks of gestation; mean ± SD). Women were assessed for pelvic floor muscle functions with surface electromyography (EMG) using vaginal probes and using the Incontinence Impact Questionnaire (IIQ). Only women able to contract pelvic floor muscles and with good quality of life based on IIQ were included for the study. Seventy women in the experimental group took part in a supervised exercise program including high-low impact aerobics and pelvic floor muscle exercises three times a week. Twenty-seven controls did not receive any exercise intervention. After 6 weeks both groups were re-tested with EMG and IIQ. Post- and pre-exercise program changes in each group were analyzed using a repeated-measures ANOVA.

Results: Women in the experimental group improved the neuromuscular activity of the pelvic floor in some motor tasks without any adverse outcomes of the intervention. After the exercise program we observed in the experimental group significantly higher EMG amplitude in the pelvic floor muscles during 3-s contractions (p = 0.014). We also noticed a beneficial trend in the increase of neuromuscular activity during 10- and 60-s contractions, but the changes were not statistically significant. The exercising women substantially improved their abilities for relaxation following 3- and 10-s contractions (p = 0.013 and p < 0.001). In controls, we reported no statistically significant improvement in either of the motor tasks. All study participants maintained good quality of life related to urinary incontinence.

Conclusion: Prenatal exercise programs that include high- and low-impact aerobics and are supported by pelvic floor muscle exercises should be recommended for pregnant women, especially those who are accustomed to higher exercise intensity before pregnancy. Nevertheless, these recommendations can be directed to continent women who can properly contract pelvic floor muscles.

ISRCTN. DOI: 10.1186/ISRCTN92265528: “Pelvic floor muscle training with surface electromyography”, retrospectively registered on the 25th of July, 2016.

Physical Activity and Bone Health: What Is the Role of Immune System? A Narrative Review of the Third Way

Bone tissue can be seen as a physiological hub of several stimuli of different origin (e.g., dietary, endocrine, nervous, immune, skeletal muscle traction, biomechanical load). Their integration, at the bone level, results in: (i) changes in mineral and protein composition and microarchitecture and, consequently, in shape and strength; (ii) modulation of calcium and phosphorous release into the bloodstream, (iii) expression and release of hormones and mediators able to communicate the current bone status to the rest of the body. Different stimuli are able to act on either one or, as usual, more levels. Physical activity is the key stimulus for bone metabolism acting in two ways: through the biomechanical load which resolves into a direct stimulation of the segment(s) involved and through an indirect load mediated by muscle traction onto the bone, which is the main physiological stimulus for bone formation, and the endocrine stimulation which causes homeostatic adaptation. The third way, in which physical activity is able to modify bone functions, passes through the immune system. It is known that immune function is modulated by physical activity; however, two recent insights have shed new light on this modulation. The first relies on the discovery of inflammasomes, receptors/sensors of the innate immunity that regulate caspase-1 activation and are, hence, the tissue triggers of inflammation in response to infections and/or stressors. The second relies on the ability of certain tissues, and particularly skeletal muscle and adipose tissue, to synthesize and secrete mediators (namely, myokines and adipokines) able to affect, profoundly, the immune function. Physical activity is known to act on both these mechanisms and, hence, its effects on bone are also mediated by the immune system activation. Indeed, that immune system and bone are tightly connected and inflammation is pivotal in determining the bone metabolic status is well-known. The aim of this narrative review is to give a complete view of the exercise-dependent immune system-mediated effects on bone metabolism and function.

Acute Postexercise Change in Circulating Irisin Is Related to More Favorable Lipid Profile in Pregnant Women Attending a Structured Exercise Program and to Less Favorable Lipid Profile in Controls: An Experimental Study with Two Groups

INTRODUCTION

The blood irisin concentrations may be affected both by exercise and pregnancy. We aimed to determine acute responses in serum irisin after a single exercise session and relationships between exercise-induced changes in this hormone and lipid profile in pregnancy.

MATERIAL AND METHODS

It was an experimental study in 20 Caucasian women in normal pregnancy (age 30 ± 3 years, 28 ± 6 weeks of gestation; mean ± SD). Participants were assigned to training (n = 8) and control groups (n = 12). Before the experiment, women from the training group attended a structured exercise program 3 times a week for 6 weeks. Blood samples were collected before and 30 minutes after a single bout of 60-minute moderate- to high-intensity exercise to determine serum levels of irisin, insulin, glucose concentration, and lipid profile.

RESULTS

At baseline, we recorded slightly lower irisin levels in the training group compared to controls (12.2 ± 2.4 and 13.9 ± 3.3 ng · ml^-1, respectively). Only in the training group all women presented increase in irisin levels after exercise (on average by 14%); and this change was statistically significant (p = 0.002). In the controls, we found positive significant relationships between postexercise irisin change and low-density lipoproteins (R = 0.594; p = 0.04) and total cholesterol (R = 0.734; p = 0.006). Surprisingly, in the training group, these relationships were also significant but inverse (R = -0.738 and p = 0.036; R = -0.833 and p = 0.01, respectively).

CONCLUSIONS

Training and control pregnant women responded differently to a single exercise session, both in the postexercise change in irisin and its relationship to the blood lipids. Only in the training group we observed the postexercise increase in irisin, which was related to more favorable lipid profile. Systematic prenatal physical activity may optimize the postexercise irisin response and lipid metabolism regulated by this hormone. Therefore, exercise programs should be promoted in pregnant women and obstetric care providers.

Six-Week Pelvic Floor Muscle Activity (sEMG) Training in Pregnant Women as Prevention of Stress Urinary Incontinence

BACKGROUND Pelvic floor muscle exercises are a widely used and well-established form of stress incontinence treatment, with success rates varying from 21% to 84%, although with a better subjective than objective outcome. MATERIAL AND METHODS "Incontinence Impact Questionnaire" (IIQ), PFM EMG assessment was done at the beginning and after the 6-week training program. RESULTS Statistically significant differences appeared in the BASE and R values. In the symptomatic group (with SUI symptoms), the value of BASE was 3.26 µV, and after training it was 3.95 µV. The R values before and after training were 4.55 µV and 4.25 µV. In the symptomatic group (without SUI symptoms), the value of BASE was 2.88 µV and 3.52 µV and R values were 7.16 µV and 3.92 µV. In the control group, BASE was 3.05 µV and 4.11 µV and R was 7.82 µV and 4.39 µV. CONCLUSIONS The results indicate that a 6-week training process influences PFM EMG activity in pregnant women. During Q, the value of PFM activity after a training session tended to increase in the symptomatic and control groups, but in the symptomatic group it remains practically unchanged. Our results show the probable process of decreasing control of PFM activity during long-lasting contractions in symptomatic and control women. The comparison of BASE before and after training averaged the values of R after five 10-s contractions and showed an increase in the Base and decrease in the R.

Who and how should prescribe and conduct exercise programs for pregnant women? Recommendation based on the European educational standards for pregnancy and postnatal exercise specialists

Extensive scientific evidence has shown that prenatal physical activity is a prerequisite for the proper course of pregnancy, fetal development, labour and delivery, and the postpartum period. In 2015, the American College of Obstetricians and Gynecologists published a breakthrough statement that inactivity in pregnancy is risky behaviour. The aim of this paper is to provide answers to the questions concerning who and how should prescribe and conduct exercise programs for pregnant women. Close cooperation between the woman, her obstetric care provider and exercise specialists is necessary to promote exercise in pregnancy. Obstetricians should carefully evaluate women with medical or obstetric complications before starting the exercises. They should also provide women with general information about the benefits of prenatal exercise and the risks of physical inactivity. On the other hand, the design and implementation of the exercise program are tasks for exercise professionals, preferably ones qualified according to the European educational standards for Pregnancy and Postnatal Exercise Specialists. Both empirical observation and scientific research confirm the need to educate obstetric care providers, exercise professionals, and both pregnant women and their families about prenatal physical activity. They all require constantly updated information on how to use exercise to stimulate the positive development of pregnancy, ensure the greatest possible well-being for the future mother, and prepare her for childbirth and the postpartum period. These educational activities should be evidence-based. They must not perpetuate unfounded opinions, often harmful to the woman's health, on what she should or should not do while exercising during pregnancy. The presented update underlines some pertinent recommendations in this area.

Irisin Maternal Plasma and Cord Blood Levels in Mothers with Spontaneous Preterm and Term Delivery

Irisin, an adipomyokine identified in 2012, has been investigated in association with common pregnancy complications, including gestational diabetes mellitus, preeclampsia, and intrauterine growth restriction. The objective of this study is to examine the potential role of irisin in preterm birth (PTB) by comparing its level between mothers with term and preterm labor. Maternal peripheral blood and cord blood samples were collected from 30 mothers who delivered prematurely and from 35 mothers who delivered at term. Irisin concentrations were measured in all samples using ELISA, and four common single nucleotide polymorphisms in the irisin gene were determined (rs16835198, rs726344, rs3480, and rs1746661). Univariable and multivariable regression modeling was applied to evaluate maternal and cord blood irisin concentrations in relation to preterm/term labor. Irisin concentration in umbilical cord blood was found to be associated with PTB in the univariable model (p = 0.046). On the other hand, no differences in maternal blood irisin levels between mothers with preterm and term deliveries were established. To the best of our knowledge, this is the first study determining irisin levels in term and preterm deliveries in maternal peripheral blood and umbilical cord blood. Our study shows a possible association between cord blood irisin concentration and PTB occurrence.