Hypertensive disorders of pregnancy are associated with dysmenorrhea in early adulthood: A cohort study

Desynchronization between Food Intake and Light Stimulations Induces Uterine Clock Quiescence in Female Mice

BACKGROUND

Dysmenorrhea is associated with breakfast skipping in young women, suggesting that fasting in the early active phase disrupts uterine functions.

OBJECTIVES

To investigate the possible involvement of the uterine clock system in fasting-induced uterine dysfunction, we examined core clock gene expressions in the uterus using a 28-h interval-fed mouse model.

METHODS

Young female mice (8 wk of age) were divided into 3 groups: group I (ad libitum feeding), group II (time-restricted feeding, initial 4 h of the active period every day), and group III (time-restricted feeding for 8 h with a 28-h cycle). Groups II and III have the same fasting interval of 20 h. After analyzing feeding and wheel running behaviors during 2 wk of dietary restriction, mice were sacrificed at 4-h intervals, and the expression profiles of clock genes in the uterus and liver were examined by qPCR.

RESULTS

The mice in group I took food mainly during the dark phase and those in group II during the initial 4 h of the dark phase, whereas those in group III delayed feeding time by 4 h per cycle. In all groups, spontaneous wheel running was observed during the dark phase. There was no difference in the quantity of feeding and the amount of running exercise among the 3 groups during the second week. The mRNA expressions of peripheral clock genes, Bmal1, Clock, Per1, Per2, Cry1, Nr1d1, and Dbp and a clock-controlled gene, Fabp1, in the uterus showed rhythmic oscillations with normal sequential expression cascade in groups I and II, whereas their expressions decreased and circadian cycles disappeared in group III. In contrast, liver core clock genes in group III showed clear circadian cycles.

CONCLUSIONS

Fluctuations in the timing of the first food intake impair the uterine clock oscillator system to reduce clock gene expressions and abolish their circadian rhythms.

Electroacupuncture treatment of primary dysmenorrhea: A randomized, participant-blinded, sham-controlled clinical trial protocol

BACKGROUND

Primary dysmenorrhea in women is a common and serious public health problem with psychological and physical effects. Painkillers have adverse effects, such as tolerance, addiction, irritation of the digestive tract, and liver and kidney damage. Electroacupuncture has been used as alternative therapy, although with no (non-anecdotal) evidence of effectiveness.

OBJECTIVE

This study aims to provide evidence for the feasibility and efficacy of electroacupuncture in the treatment of primary dysmenorrhea. Moreover, by observing changes in serum and urine metabolites, we will evaluate the putative mechanisms mediating electroacupuncture effects in primary dysmenorrhea.

METHODS

This multicenter, randomized, participant-blinded, sham-controlled clinical trial including 336 women with primary dysmenorrhea is being conducted at three hospital centers in China and consists of a 12-week treatment and a 3-month follow-up. Women will undergo electroacupuncture (n = 168) or sham acupuncture (n = 168), beginning 7 days before their menstruation, once per day, until menstruation. Each menstrual cycle equals one course of treatment, and we will evaluate a total of three courses of treatment. The primary outcome of interest is the change in visual analogue scale scores before and after treatment. The secondary outcomes include changes in the numeric rating scale, Cox Menstrual Symptom Scale, traditional Chinese medicine symptoms, the Self-Rating Anxiety Scale, Self-Rating Depression Scale, and 36-Item Short Form questionnaire scores, and a safety evaluation. Moreover, we will preliminarily investigate the metabolomics mechanism as a potential mediator of the association between electroacupuncture and primary dysmenorrhea symptomology.

DISCUSSION

We aim to find a suitable non-medicinal alternative for primary dysmenorrhea treatment to reduce reliance on non-steroidal anti-inflammatory drugs.

TRIAL REGISTRATION

Chinese Clinical Trial Registry: ChiCTR2100054234; http://www.chictr.org.cn/.

Effect of hypertensive disorders of pregnancy on pubertal development in daughters and sons: a systematic review and meta-analysis

Hypertensive disorders of pregnancy (HDP) are a major cause of maternal and offspring morbidity and mortality worldwide. Several studies in recent years have focused on the link between HDP and pubertal development in offspring. The goal of this study was to synthesize the published literature on the effect of HDP on pubertal development in offspring by a systematic review and meta-analysis (PROSPERO 2021: CRD42020148736). A systematic literature search of several databases was conducted through December 2021, focusing on studies reporting pubertal development in offspring of women with and without HDP exposure. Primary outcomes of interest included offspring body mass index (BMI), height, waist and hip circumference, fat mass, pubarche, thelarche, and age at menarche. A total of 21 studies were finally included. Significantly higher values of BMI (SMD: 0.16 [0.11, 0.22]; p < 0.01) and waist circumference (SMD: 0.21 [0.14, 0.29]; p < 0.01) were found in offspring exposed to maternal HDP. In addition, a tendency of the early development of secondary sexual characteristics only in daughters was presented in offspring whose mothers were diagnosed with HDP. The findings imply a possible effect of HDP on pubertal development in offspring, especially for their BMI and waist circumference, which highlights the importance of focusing on adolescent developmental abnormalities in offspring exposed to HDP.

Skipping breakfast during pregnancy and hypertensive disorders of pregnancy in Japanese women: the Tohoku medical megabank project birth and three-generation cohort study

BACKGROUND

Hypertensive disorders of pregnancy (HDP) adversely affect the prognosis of mother and child, and the prognosis depends on the subtype of HDP. Skipping breakfast may be associated with increased blood pressure due to disruption of the circadian clock, but the association with the development of HDP has not been studied. The purpose of this study was to examine the association between skipping breakfast and the development of HDP and HDP subtypes in Japanese pregnant women.

METHODS

Of the pregnant women who participated in the Tohoku Medical Megabank Project Three-Generation Cohort Study, 18,839 who answered the required questions were included in the analysis. This study had a cross-sectional design. The breakfast intake frequency from pre-pregnancy to early pregnancy was classified into four groups: daily, 5-6 times per week, 3-4 times per week, and 0-2 times per week. HDP was classified into gestational hypertension (GH), chronic hypertension (CH), preeclampsia (PE), and severe preeclampsia (SuPE). Multiple logistic regression analysis and multinomial logistic analysis were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for breakfast intake frequency and development of HDP or HDP subtypes. We performed a stratified analysis based on energy intake.

RESULTS

Of the participants, 74.3% consumed breakfast daily, and 11.1% developed HDP. Women who consumed breakfast 0-2 times per week had a higher risk of HDP (OR: 1.33, 95% CI: 1.14-1.56), CH (OR: 1.63, 95% CI: 1.21-2.19), and PE (OR: 1.68, 95% CI: 1.27-2.21) than those who consumed breakfast daily. No association was found between skipping breakfast and the risk of developing GH (OR: 1.26, 95% CI: 0.99-1.61) and SuPE (OR: 0.91, 95% CI: 0.55-1.49). Stratified analysis showed that the risk of developing HDP due to skipping breakfast was highest in the group with the highest daily energy intake.

CONCLUSIONS

Skipping breakfast during pre-to early pregnancy is associated with the development of HDP. Further longitudinal studies are required to clarify the causal association between skipping breakfast and HDP.

Uterine Deletion of Bmal1 Impairs Placental Vascularization and Induces Intrauterine Fetal Death in Mice

Recently, it was demonstrated that the expression of BMAL1 was decreased in the endometrium of women suffering from recurrent spontaneous abortion. To investigate the pathological roles of uterine clock genes during pregnancy, we produced conditional deletion of uterine Bmal1 (cKO) mice and found that cKO mice could receive embryo implantation but not sustain pregnancy. Gene ontology analysis of microarray suggested that uterine NK (uNK) cell function was suppressed in cKO mice. Histological examination revealed the poor formation of maternal vascular spaces in the placenta. In contrast to WT mice, uNK cells in the spongiotrophoblast layer, where maternal uNK cells are directly in contact with fetal trophoblast, hardly expressed an immunosuppressive NK marker, CD161, in cKO mice. By progesterone supplementation, pregnancy could be sustained until the end of pregnancy in some cKO mice. Although this treatment did not improve the structural abnormalities of the placenta, it recruited CD161-positive NK cells into the spongiotrophoblast layer in cKO mice. These findings indicate that the uterine clock system may be critical for pregnancy maintenance after embryo implantation.

Association of preconception dysmenorrhea with obstetric complications: the Japan Environment and Children's Study

Background

The association of maternal preconception dysmenorrhea, especially primary dysmenorrhea, with obstetric complications has not been clearly described. Therefore, we evaluated the association of preconception dysmenorrhea with obstetric complications while accounting for the presence of pelvic pathologies.

Methods

We analyzed the data of women with singleton live births at and after 22 weeks of gestation enrolled in the Japan Environment and Children’s Study, a nationwide birth cohort study, between 2011 and 2014. Participants with psychological disorders were excluded. Preconception dysmenorrhea, identified in the medical record transcripts, was categorized into mild dysmenorrhea (MD) and severe dysmenorrhea (SD). Furthermore, excluding those who had pelvic pathologies via self-reported questionnaires (endometriosis, adenomyosis, and uterine myomas) with MD and SD, preconception dysmenorrhea was categorized into mild primary dysmenorrhea (MPD) and severe primary dysmenorrhea (SPD), respectively. Using multiple logistic regression, adjusted odds ratios (aORs) for obstetric complications, including preterm birth (PTB) before 37 weeks and 34 weeks, small-for-gestational-age infants, preterm premature rupture of membrane, and hypertensive disorders of pregnancy, were calculated (considering confounders) in women with (1) MD or SD and (2) MPD or SPD. Women without preconception dysmenorrhea were used as a reference.

Results

A total of 80,242 participants were analyzed. In women with SD, the aOR for PTB before 37 weeks was 1.38 (95% confidence interval [CI] 1.10, 1.72). In women with SPD, the aOR for PTB before 37 weeks was 1.32 (95% CI 1.02, 1.71). There was no association between women with MD or MPD and obstetric complications.

Conclusions

SD and SPD are significantly associated with an increased incidence of PTB before 37 weeks. Care providers should provide proper counseling regarding the association between preconception dysmenorrhea and obstetric complications. Optimal management of pregnant women with preconception dysmenorrhea to reduce the incidence of PTB should be elucidated in further studies, with detailed clinical data of pelvic pathologies.

Time-Restricted Feeding Regulates Circadian Rhythm of Murine Uterine Clock

BACKGROUND

Skipping breakfast is associated with dysmenorrhea in young women. This suggests that the delay of food intake in the active phase impairs uterine functions by interfering with circadian rhythms.

OBJECTIVES

To examine the relation between the delay of feeding and uterine circadian rhythms, we investigated the effects of the first meal occasion in the active phase on the uterine clock.

METHODS

Zeitgeber time (ZT) was defined as ZT0 (08:45) with lights on and ZT12 (20:45) with lights off. Young female mice (8 wk of age) were divided into 3 groups: group I (ad libitum consumption), group II (time-restricted feeding during ZT12-16, initial 4 h of the active period), and group III (time-restricted feeding during ZT20-24, last 4 h of the active period, a breakfast-skipping model). After 2 wk of dietary restriction, mice in each group were killed at 4-h intervals and the expression profiles of uterine clock genes, Bmal1 (brain and muscle aryl hydrocarbon receptor nuclear translocator-like protein 1), Per1 (period circadian clock 1), Per2, and Cry1 (cryptochrome 1), were examined.

RESULTS

qPCR and western blot analyses demonstrated synchronized circadian clock gene expression within the uterus. Immunohistochemical analysis confirmed that BMAL1 protein expression was synchronized among the endometrium and myometrium. In groups I and II, mRNA expression of Bmal1 was elevated after ZT12 at the start of the active phase. In contrast, Bmal1 expression was elevated just after ZT20 in group III, showing that the uterine clock rhythm had shifted 8 h backward. The changes in BMAL1 protein expression were confirmed by western blot analysis.

CONCLUSIONS

This study is the first to indicate that time-restricted feeding regulates a circadian rhythm of the uterine clock that is synchronized throughout the uterine body. These findings suggest that the uterine clock system is a new candidate to explain the etiology of breakfast skipping-induced uterine dysfunction.