Alterations in the structural characteristics of rectus abdominis muscles caused by diabetes and pregnancy: A comparative study of the rat model and women

Development of a natural rubber latex-based biodevice with mesenchymal stem cells as a potential treatment for skeletal muscle regeneration in gestational diabetes-induced myopathy

Women with gestational diabetes mellitus show a high risk of developing Gestational Diabetes Induced Myopathy (GDiM). GDiM is characterized by significant pelvic floor skeletal muscle atrophy and urinary incontinence. This study aimed to develop a natural rubber latex (NRL) based biodevice with mesenchymal/stromal stem cells (MSCs) for skeletal muscle regeneration for women with GDiM. NRL showed porosity, roughness, biocompatibility, and bioactivity. MSCs adhesion on the NRL scaffold surface was assessed by scanning electron microscopy (SEM), confocal microscopy, and zymography. The scaffold's physicochemical and biological properties were carried out by Fourier transform infrared spectroscopy (FTIR), swelling and degradation studies, hemolytic activity, and antioxidant activity (AA), using Electronic Paramagnetic Resonance (EPR). MSCs in culture expressed CD90, adhered to plastic, differentiated, and produced fibroblast colonies. A high rate of cell proliferation was seen in MSCs on the NRL scaffold. FTIR analysis confirmed protein structures and polyisoprene in the scaffold. Swelling and degradation showed low water uptake and weight loss. Furthermore, NRL presented a hemolytic rate of 2.90 ± 0.26 % for 24 h, and EPR revealed the scaffold's strong AA. The generated biodevice has potential for muscle regeneration and may be useful as a therapeutic option for skeletal muscle disorders in GDiM or urinary incontinence.

Endurance exercise-induced histone methylation modification involved in skeletal muscle fiber type transition and mitochondrial biogenesis

Skeletal muscle is a highly heterogeneous tissue, and its contractile proteins are composed of different isoforms, forming various types of muscle fiber, each of which has its own metabolic characteristics. It has been demonstrated that endurance exercise induces the transition of muscle fibers from fast-twitch to slow-twitch muscle fiber type. Herein, we discover a novel epigenetic mechanism for muscle contractile property tightly coupled to its metabolic capacity during muscle fiber type transition with exercise training. Our results show that an 8-week endurance exercise induces histone methylation remodeling of PGC-1α and myosin heavy chain (MHC) isoforms in the rat gastrocnemius muscle, accompanied by increased mitochondrial biogenesis and an elevated ratio of slow-twitch to fast-twitch fibers. Furthermore, to verify the roles of reactive oxygen species (ROS) and AMPK in exercise-regulated epigenetic modifications and muscle fiber type transitions, mouse C2C12 myotubes were used. It was shown that rotenone activates ROS/AMPK pathway and histone methylation enzymes, which then promote mitochondrial biogenesis and MHC slow isoform expression. Mitoquinone (MitoQ) partially blocking rotenone-treated model confirms the role of ROS in coupling mitochondrial biogenesis with muscle fiber type. In conclusion, endurance exercise couples mitochondrial biogenesis with MHC slow isoform by remodeling histone methylation, which in turn promotes the transition of fast-twitch to slow-twitch muscle fibers. The ROS/AMPK pathway may be involved in the regulation of histone methylation enzymes by endurance exercise.

Exercise couples mitochondrial function with skeletal muscle fiber type via ROS-mediated epigenetic modification

Skeletal muscle is a heterogeneous tissue composed of different types of muscle fibers, demonstrating substantial plasticity. Physiological or pathological stimuli can induce transitions in muscle fiber types. However, the precise regulatory mechanisms behind these transitions remains unclear. This paper reviews the classification and characteristics of muscle fibers, along with the classical mechanisms of muscle fiber type transitions. Additionally, the role of exercise-induced muscle fiber type transitions in disease intervention is reviewed. Epigenetic pathways mediate cellular adaptations and thus represent potential targets for regulating muscle fiber type transitions. This paper focuses on the mechanisms by which epigenetic modifications couple mitochondrial function and contraction characteristics. Reactive Oxygen Species (ROS) are critical signaling regulators for the health-promoting effects of exercise. Finally, we discuss the role of exercise-induced ROS in regulating epigenetic modifications and the transition of muscle fiber types.

Role of dietary food intake patterns, anthropometric measures, and multiple biochemical markers in the development of pregnancy-specific urinary incontinence in gestational diabetes mellitus

OBJECTIVES

The aim of this study was to assess maternal dietary food intake patterns, anthropometric measures, and multiple biochemical markers in women with gestational diabetes mellitus and pregnancy-specific urinary incontinence and to explore whether antedating gestational diabetes mellitus environment affects the pregnancy-specific urinary incontinence development in a cohort of pregnant women with gestational diabetes mellitus and pregnancy-specific urinary incontinence.

METHODS

Maternal dietary information and anthropometric measurements were collected. At 24 wk of gestation, with a fasting venipuncture sample, current blood samples for biochemical markers of hormones, vitamins, and minerals were analyzed. The groups were compared in terms of numerical variables using analysis of variance for independent samples followed by multiple comparisons.

RESULTS

Of the 900 pregnant women with complete data, pregnant women in the gestational diabetes mellitus pregnancy-specific urinary incontinence group had higher body mass index during pregnancy, arm circumference, and triceps skinfold than the non-gestational diabetes mellitus continent and non-gestational diabetes mellitus pregnancy-specific urinary incontinence groups, characterizing an obesogenic maternal environment. Regarding dietary food intake, significant increases in aromatic amino acids, branched-chain amino acids, dietary fiber, magnesium, zinc, and water were observed in pregnancy-specific urinary incontinence group compared with the non-gestational diabetes mellitus continent group. Serum vitamin C was reduced in the gestational diabetes mellitus pregnancy-specific urinary incontinence group compared with the non-gestational diabetes mellitus pregnancy-specific urinary incontinence group.

CONCLUSIONS

This study emphasizes the necessity for a comprehensive strategy for gestational diabetes mellitus women with pregnancy-specific urinary incontinence in terms of deviation in maternal adaptation trending toward obesity and maternal micronutrients deficiencies.

The role of Gestational Diabetes Mellitus and pelvic floor 3D-ultrasound assessment during pregnancy predicting urinary incontinence: a prospective cohort study

Postpartum urinary incontinence may have a severe impact on women's health. Despite pregnancy and parturition being the most recognized risk factors, methods to identify new pregnant predictor risk factors are needed. Our study investigated the Gestational Diabetes Mellitus, clinical and pelvic floor 3D-ultrasound markers in pregnant women as predictors for 6-18 months of urinary incontinence. This prospective cohort study included nulliparous pregnant women submitted to Gestational Diabetes Mellitus screening in the second trimester. Pelvic floor 3D Ultrasound was performed at the second and third trimesters of gestation to evaluate the pelvic floor muscles and functions. Clinical data, the ICIQ-SF, and ISI questionnaires for urinary incontinence were applied in the third trimester and 6-18 months postpartum. Univariate analysis (P < .20) to extract risk factors variables and multivariate logistic regression analysis (P < .05) to obtain the adjusted relative ratio for urinary incontinence were performed. A total of 93 participants concluded the follow-up. Using the variables obtained by univariate analysis and after adjustments for potential confounders, multivariate analysis revealed that Gestational Diabetes Mellitus exposure was a solid and independent risk factor for 6-18 months of urinary incontinence (Adjusted RR 8.08; 95%CI 1.17-55.87; P:0.034). In addition, a higher Hiatal area observed in distension maneuver from the second to third trimester was negatively associated (Adjusted RR 0.96; 95%CI 0.93-0.99; P:0.023). In conclusion, Gestational Diabetes Mellitus was positively associated with 6-18 months of urinary incontinence, and higher Hiatal area distension was negatively associated.

Gestational diabetes mellitus and pelvic floor function 6 weeks postpartum in Chinese women

INTRODUCTION AND HYPOTHESIS

With the significant increase in its incidence, gestational diabetes mellitus (GDM) has received growing attention for its effect on pelvic floor function. This study was aimed at investigating the association of GDM with pelvic floor function and diastasis recti abdominis (DRA) in postpartum women.

METHODS

This is a retrospective cohort study. At 6 weeks postpartum, 1,133 postpartum women with vaginal delivery underwent routine examinations including measurement of the pelvic floor muscle (PFM) strength and endurance, determination of the stress urinary incontinence (SUI) by questionnaire, quantification of pelvic organ prolapse (POP) and assessment of DRA. Statistical analysis was performed using binary logistic regression and multiple linear regression analysis.

RESULTS

One hundred and seventy-six (176) of the 1,133 women were confirmed to be suffering from GDM, with a rate of 15.53% (176 out of 1,133). The age and pre-pregnancy body mass index of the GDM group were significantly higher than those without GDM (p < 0.05). The GDM group was more likely to have smaller gestational age and a higher chance of having to undergo a lateral episiotomy. No statistically significant differences are found in PFM endurance (B: -0.025, p = 0.462) or PFM strength (B: -0.001, p = 0.979) between women with and without GDM. And these two groups are not significantly different in terms of the prevalence of SUI (19.3% vs 20.4%), POP (35.8% vs 37.5%) and DRA (29.0% vs 25.8%; p > 0.05).

CONCLUSIONS

Pelvic floor muscle function and SUI/POP/DRA prevalence of women at 6 weeks postpartum are not significantly affected by GDM.

Impact of Obesity and Hyperglycemia on Pregnancy-specific Urinary Incontinence

OBJECTIVE

 The lack of data on the impact of hyperglycemia and obesity on the prevalence of pregnancy-specific urinary incontinence (PSUI) led us to conduct a cross-sectional study on the prevalence and characteristics of PSUI using validated questionnaires and clinical data.

METHODS

 This cross-sectional study included 539 women with a gestational age of 34 weeks who visited a tertiary university hospital between 2015 and 2018. The main outcome measures were the prevalence of PSUI, the International Consultation on Incontinence Questionnaire Short Form (ICIQ-SF), and the Incontinence Severity Index (ISI) questionnaires. The women were classified into four groups: normoglycemic lean, normoglycemic obese, hyperglycemic lean, and hyperglycemic obese. The differences between groups were tested using descriptive statistics. Associations were estimated using logistic regression analysis and presented as unadjusted and adjusted odds ratios.

RESULTS

 Prevalence rates of PSUI were no different between groups. However, significant difference in hyperglycemic groups worse scores for severe and very severe PSUI. When adjusted data for confound factors was compared with normoglycemic lean group, the hyperglycemic obese group had significantly higher odds for severe and very severe forms of UI using ICIQ-SF (aOR 3.157; 95% CI 1.308 to 7.263) and ISI (aOR 20.324; 95% CI 2.265 to 182.329) questionnaires and highest perceived impact of PSUI (aOR 4.449; 95% CI 1.591 to 12.442).

CONCLUSION

 Our data indicate that obesity and hyperglycemia during pregnancy significantly increase the odds of severe forms and perceived impact of PSUI. Therefore, further effective preventive and curative treatments are greatly needed.

Transcriptomic Profiling of Rectus Abdominis Muscle in Women with Gestational Diabetes-Induced Myopathy: Characterization of Pathophysiology and Potential Muscle Biomarkers of Pregnancy-Specific Urinary Incontinence

Gestational diabetes mellitus (GDM) is recognized as a "window of opportunity" for the future prediction of such complications as type 2 diabetes mellitus and pelvic floor muscle disorders, including urinary incontinence and genitourinary dysfunction. Translational studies have reported that pelvic floor muscle disorders are due to a GDM-induced-myopathy (GDiM) of the pelvic floor muscle and rectus abdominis muscle (RAM). We now describe the transcriptome profiling of the RAM obtained by Cesarean section from GDM and non-GDM women with and without pregnancy-specific urinary incontinence (PSUI). We identified 650 genes in total, and the differentially expressed genes were defined by comparing three control groups to the GDM with PSUI group (GDiM). Enrichment analysis showed that GDM with PSUI was associated with decreased gene expression related to muscle structure and muscle protein synthesis, the reduced ability of muscle fibers to ameliorate muscle damage, and the altered the maintenance and generation of energy through glycogenesis. Potential genetic muscle biomarkers were validated by RT-PCR, and their relationship to the pathophysiology of the disease was verified. These findings help elucidate the molecular mechanisms of GDiM and will promote the development of innovative interventions to prevent and treat complications such as post-GDM urinary incontinence.

Viability of ex-vivo myography as a diagnostic tool for rectus abdominis muscle electrical activity collected at Cesarean section within a diamater cohort study

Background

Ex-vivo myography enables the assessment of muscle electrical activity response. This study explored the viability of determining the physiological responses in muscles without tendon, as rectus abdominis muscle (RAM), through ex-vivo myography to assess its potential as a diagnostic tool.

Results

All tested RAM samples (five different samples) show patterns of electrical activity. A positive response was observed in 100% of the programmed stimulation. RAM 3 showed greater weight (0.47 g), length (1.66 cm), and width (0.77 cm) compared to RAM 1, RAM 2, RAM 4 and RAM 5 with more sustained electrical activity over time, a higher percentage of fatigue was analyzed at half the time of the electrical activity. The order of electrical activity (Mn) was RAM 3 > RAM 5 > RAM 1 > RAM 4 > RAM 2. No electrical activity was recorded in the Sham group.

Conclusions

This study shows that it is feasible to assess the physiological responses of striated muscle without tendon as RAM, obtained at C-section, under ex vivo myography. These results could be recorded, properly analyzed, and demonstrated its potential as a diagnostic tool for rectus abdominis muscle electrical activity.

Gestational diabetes is associated with alteration on pelvic floor muscle activation pattern during pregnancy and postpartum: Prospective cohort using electromyography assessment

Background and objective

Gestational diabetes mellitus (GDM) is a comorbidity which may cause acute and lifelong disorders to mother and child. Alterations in muscular and connective tissues have been associated with GDM in translation studies, characterizing gestational diabetic myopathy. Pregnancy-specific urinary incontinence and sexual disabilities, disorders that depend on the pelvic floor muscle (PFM) integrity, are also associated with GDM both during and after pregnancy. The aim was to compare PFM activation patterns between GDM and non-GDM women from 24-30 gestational weeks to 18-24 months postpartum during a standard clinical test during gestation and postpartum.

Methods

We conducted a prospective three-time-point cohort study from gestation (24-30 weeks-T1, and 36-38 weeks-T2) to 18-24 months postpartum (T3). PFM electromyography was recorded in primigravida or primiparous women with one previous elective c-section with or without the diagnosis of GDM according to the American Diabetes Association criteria. A careful explanation of the muscle anatomy and functionality of the PFM was given to participants before EMG assessment. The outcome measures were PFM activation patterns assessed during pregnancy and postpartum, comparing intra and between groups. PFM activation patterns were assessed by normalized electromyography signal at rest and during 1-second (sec) phasic, 10-sec hold, and 60-sec sustained contractions.

Results

Demographic and obstetric data showed homogeneity between groups. The GDM group achieved peak PFM EMG amplitudes similarly to the non-GDM group, but they took longer to return to baseline levels during the ~1-sec contraction (flicks). During 10-sec hold contractions, the GDM group sustained lower levels of PFM activation than the non-GDM group at both 36-38 weeks of gestation and 18-24 months postpartum when compared to the non-GDM group.

Conclusion

The results suggest that GDM impaired PFM control mainly on 1-sec flicks and 10-sec hold contraction, which appears to develop during late pregnancy and extends long-term postpartum. This motor behavior may play a role on pelvic floor dysfunctions.

Relaxin-2 during pregnancy according to glycemia, continence status, and pelvic floor muscle function

INTRODUCTION AND HYPOTHESIS

To investigate relaxin-2 concentration comparing gestational diabetes mellitus (GDM) and non-GDM patients during pregnancy according to urinary incontinence (UI) and pelvic function status.

METHODS

This is a cross-sectional study evaluating 282 pregnant women from 24 weeks of gestation. The participants were divided into two groups, non-GDM and GDM, according to American Diabetes Association's diabetes mellitus gestational threshold. In addition, according to subanalysis, both groups were subdivided according to the presence of pregnancy-specific urinary incontinence: non-GDM continent, non-GDM incontinent, GDM continent, and GDM incontinent. All participants filled in questionnaires on clinical, obstetric, and urinary continence status (International Consultation on Incontinence Questionnaire-Short Form, ICIQ-SF, and Incontinence Severity Index, ISI), followed by pelvic floor muscle evaluation by the PERFECT scheme in which strength, endurance, and speed of contractions were evaluated.

RESULTS

Serum relaxin-2 concentrations were significantly lower in pregnant women with pregnancy-specific urinary incontinence in both non-GDM and GDM patients, but GDM showed the lowest concentration. In addition, the stratification of the groups according to pelvic floor muscle strength showed that pregnant patients with GDM and modified Oxford scale 0-2 had significantly lower levels than those who were non-GDM and GDM with Modified Oxford Scale 3-5. Relaxin-2 level was much lower in GDM incontinent pregnant women with MOS 0-2 compared to the other three groups.

CONCLUSIONS

Lower relaxin-2 concentration was associated with the presence of pregnancy-specific urinary incontinence, but the combination of GDM, pregnancy-specific urinary incontinence, and lower levels of pelvic floor strength led to lower levels of relaxin-2 compared to the other three groups.

Reversal of diabetic-induced myopathy by swimming exercise in pregnant rats: a translational intervention study

Gestational diabetes mellitus (GDM) plus rectus abdominis muscle (RAM) myopathy predicts long-term urinary incontinence (UI). Atrophic and stiff RAM are characteristics of diabetes-induced myopathy (DiM) in pregnant rats. This study aimed to determine whether swimming exercise (SE) has a therapeutic effect in mild hyperglycemic pregnant rats model. We hypothesized that SE training might help to reverse RAM DiM. Mild hyperglycemic pregnant rats model was obtained by a unique subcutaneous injection of 100 mg/kg streptozotocin (diabetic group) or citrate buffer (non-diabetic group) on the first day of life in Wistar female newborns. At 90 days of life, the rats are mated and randomly allocated to remain sedentary or subjected to a SE protocol. The SE protocol started at gestational day 0 and consisted of 60 min/day for 6 days/week in a period of 20 days in a swim tunnel. On day 21, rats were sacrificed, and RAM was collected and studied by picrosirius red, immunohistochemistry, and transmission electron microscopy. The SE protocol increased the fiber area and diameter, and the slow-twitch and fast-twitch fiber area and diameter in the diabetic exercised group, a finding was also seen in control sedentary animals. There was a decreased type I collagen but not type III collagen area and showed a similar type I/type III ratio compared with the control sedentary group. In conclusion, SE during pregnancy reversed the RAM DiM in pregnant rats. These findings may be a potential protocol to consider in patients with RAM damage caused by GDM.

Pelvic floor muscle dysfunction at 3D transperineal ultrasound in maternal exposure to gestational diabetes mellitus: A prospective cohort study during pregnancy

AIM

This study aimed to assess, for the first time, the dynamic morphometry of pelvic floor muscles (PFM) using three-dimensional transperineal ultrasound (3D-TPUS) and its progression at two-time points of gestation between women with and without gestational diabetes mellitus (GDM), and whether the PFM dysfunction is connected to GDM.

METHODS

The study comprised 83 consecutive pregnant women with (n = 38) and without (n = 45) GDM screened at 24-30 and 38-40 weeks of gestation. 3D-TPUS and a mobility test were used to quantify PFM dynamic morphometry during maximum contraction and the Valsalva maneuver.

RESULTS

When compared to the control group, GDM women had no significant variations in all levator hiatal dimensions at 24-30 weeks of gestation. Meanwhile, women with GDM experienced an increase in levator hiatal area (LHa) (p < 0.000) during PFM contraction and enlargement in LHa (p < 0.001) during Valsalva maneuver (p = 0.010) at 38-40 weeks of gestation. As a result, the mobility index among GDM women had a lower value (p = 0.000). The dynamic morphometry development of PFM in GDM women at two stages during pregnancy revealed a substantial decrease (p = 0.000) in all LHa dimensions of contraction, distension, and mobility.

CONCLUSIONS

Using 3D-TPUS, we found that GDM women had a specific pattern of PFM functional changes in the third trimester of pregnancy. These initial findings revealed alterations in PFM functionality, such as decreased contractility, distensibility, or mobility. This dysfunctional PFM could contribute to the long-term development of pelvic floor dysfunction years after a GDM pregnancy.

Deleterious effects of gestational diabetes mellitus on the characteristics of the rectus abdominis muscle associated with pregnancy-specific urinary incontinence

AIMS

To evaluate the effects of gestational diabetes mellitus (GDM) on the structural characteristics of the rectus abdominis muscle (RAM) and its indirect effects on pregnancy-specific urinary incontinence (PSUI).

METHODS

A total of 92 pregnant women were divided into four groups, according to their clinical conditions: non-GDM continent, non-GDM associated PSUI, GDM continent and GDM associated PSUI. The muscle morphometry (histochemistry and immunohistochemistry) for the fiber types and collagen fiber distribution, the ultrastructural analysis (transmission electron microscopy), the protein expression of fiber types and calcium signaling (Western blotting), and the content of types I and III collagen fiber (ELISA) in RAM collected at delivery were assessed.

RESULTS

The GDM groups presented a significantly increased number of slow fibers and slow-twitch oxidative fiber expression; decreased fiber area, number of fast fibers, and area of collagen; an increase in central nuclei; ultrastructural alterations with focal lesion areas such as myeloid structures, sarcomere disorganization, and mitochondrial alteration. The PSUI groups presented a considerable decrease in types I and III collagen contents and the localization of collagen fiber.

CONCLUSIONS

Our data reveal that GDM causes morphological, biochemical and physiological changes in the RAM, and this might predispose women to PSUI.