Genome-wide association analysis of pain severity in dysmenorrhea identifies association at chromosome 1p13.2, near the nerve growth factor locus

Altered cognitive control network mediates the association between long-term pain and anxiety symptoms in primary dysmenorrhea

Neuroimaging studies have demonstrated the association of the cognitive control network (CCN) with the maintenance of chronic pain. However, whether and how dorsolateral prefrontal cortex (DLPFC), a key region within the CCN, is altered in menstrual pain is unclear. In this study, we aimed to investigate alterations in the DLPFC functional connectivity network in patients with primary dysmenorrhea (PDM). The study comprised 41 PDM patients and 39 matched healthy controls (HCs), all of whom underwent a resting-state functional MRI scan during the menstrual stage. All participants were instructed to complete the clinical assessment before the MRI scan. We used the DLPFC as the seed in resting-state functional connectivity (rsFC) analysis to investigate the difference between PDM patients and HCs. Compared to HCs, PDM patients showed increased right DLPFC rsFC at the bilateral lingual gyrus, dorsal anterior cingulate cortex (dACC), and middle cingulate cortex, and decreased left DLPFC rsFC at the right orbital frontal cortex. In addition, increased right DLPFC-bilateral dACC connectivity mediated the association between disease duration and the self-rating anxiety scale (SAS) scores in PDM patients. We confirmed that the DLPFC-dACC rsFC was associated with higher SAS scores, which could mediate the association between disease duration and anxiety symptoms in patients with PDM. Our findings provide central pathological evidence for an abnormal rsFC of the CCN in PDM patients, which may contribute to a better understanding of the neuropathophysiological mechanisms underlying PDM.

Assessment of prevalence, knowledge and health-related practices of dysmenorrhea among Malaysian women in Kuala Lumpur: a cross-sectional survey

BACKGROUND

Menstruation is a natural phenomenon considered an important indicator of women's health, reflecting their endocrine function. Women in low middle income countries face substantial menstrual hygiene management challenges. Data on the knowledge of dysmenorrhea and health-related practices among Malaysian women are scarce. The present study aimed to investigate the prevalence of dysmenorrhea among Malaysian women in Kuala Lumpur and its association with socio-demographic factors, knowledge level, and general practices.

METHOD

A cross-sectional study was carried out among Malaysian women in Kuala Lumpur. A total of 362 unmarried women, nulliparous and aged between 18 and 25 years old, were included in this study. Participants were conveniently recruited through online platforms as well as face to face using a self-administered questionnaire with five sections consisting of demographics, menstrual characteristics, Working ability, Location, Intensity, Days of pain, Dysmenorrhea (WaLIDD) score for diagnosing and assessing the severity of dysmenorrhea as well as an evaluation of respondents' general knowledge and practices towards dysmenorrhea. The collected data were analysed using the SPSS tool, a descriptive statistic was used to report demographic characteristics. Inferential statistics was used to report the differentiation, association, and correlations of the variables.

RESULTS

The prevalence of primary dysmenorrhea was 73.2%. It was found that the majority of the respondents had poor knowledge (60%) and poor practices (61.88%) of dysmenorrhea. The most common preventive practices among the respondents were using dietary supplements, and herbs, taking a rest and exercising. The findings also indicated that dysmenorrhea among the respondents was significantly associated with family history of dysmenorrhea (p = 0.002), monthly income (p = 0.001), and knowledge level (p = 0.001).

CONCLUSION

Dysmenorrhea has a high prevalence among women in Malaysia in Kula Lumpur driven by low knowledge and lack of evidence-based practices among these women. Thus, it is critical for Government and healthcare authorities to promote education related to women health among Malaysian women.

A systematic review of genome-wide association studies for pain, nociception, neuropathy, and pain treatment responses

ABSTRACT

Pain is the leading cause of disability worldwide, imposing an enormous burden on personal health and society. Pain is a multifactorial and multidimensional problem. Currently, there is (some) evidence that genetic factors could partially explain individual susceptibility to pain and interpersonal differences in pain treatment response. To better understand the underlying genetic mechanisms of pain, we systematically reviewed and summarized genome-wide association studies (GWASes) investigating the associations between genetic variants and pain/pain-related phenotypes in humans. We reviewed 57 full-text articles and identified 30 loci reported in more than 1 study. To check whether genes described in this review are associated with (other) pain phenotypes, we searched 2 pain genetic databases, Human Pain Genetics Database and Mouse Pain Genetics Database. Six GWAS-identified genes/loci were also reported in those databases, mainly involved in neurological functions and inflammation. These findings demonstrate an important contribution of genetic factors to the risk of pain and pain-related phenotypes. However, replication studies with consistent phenotype definitions and sufficient statistical power are required to validate these pain-associated genes further. Our review also highlights the need for bioinformatic tools to elucidate the function of identified genes/loci. We believe that a better understanding of the genetic background of pain will shed light on the underlying biological mechanisms of pain and benefit patients by improving the clinical management of pain.

Distribution of Brain-Derived Neurotrophic Factor in the Brain of the Small-Spotted Catshark Scyliorhinus canicula, and Evolution of Neurotrophins in Basal Vertebrates

Neurotrophins (NTFs) are structurally related neurotrophic factors essential for differentiation, survival, neurite outgrowth, and the plasticity of neurons. Abnormalities associated with neurotrophin-signaling (NTF-signaling) were associated with neuropathies, neurodegenerative disorders, and age-associated cognitive decline. Among the neurotrophins, brain-derived neurotrophic factor (BDNF) has the highest expression and is expressed in mammals by specific cells throughout the brain, with particularly high expression in the hippocampus and cerebral cortex. Whole genome sequencing efforts showed that NTF signaling evolved before the evolution of Vertebrates; thus, the shared ancestor of Protostomes, Cyclostomes, and Deuterostomes must have possessed a single ortholog of neurotrophins. After the first round of whole genome duplication that occurred in the last common ancestor of Vertebrates, the presence of two neurotrophins in Agnatha was hypothesized, while the monophyletic group of cartilaginous fishes, or Chondrichthyans, was situated immediately after the second whole genome duplication round that occurred in the last common ancestor of Gnathostomes. Chondrichthyans represent the outgroup of all other living jawed vertebrates (Gnathostomes) and the sister group of Osteichthyans (comprehensive of Actinopterygians and Sarcopterygians). We were able to first identify the second neurotrophin in Agnatha. Secondly, we expanded our analysis to include the Chondrichthyans, with their strategic phylogenetic position as the most basal extant Gnathostome taxon. Results from the phylogenetic analysis confirmed the presence of four neurotrophins in the Chondrichthyans, namely the orthologs of the four mammalian neurotrophins BDNF, NGF, NT-3, and NT-4. We then proceeded to study the expression of BDNF in the adult brain of the Chondrichthyan Scyliorhinus canicula. Our results showed that BDNF is highly expressed in the S. canicula brain and that its expression is highest in the Telencephalon, while the Mesencephalic and Diencephalic areas showed expression of BDNF in isolated and well-defined cell groups. NGF was expressed at much lower levels that could be detected by PCR but not by in situ hybridization. Our results warrant further investigations in Chondrichthyans to characterize the putative ancestral function of neurotrophins in Vertebrates.

Disease Burden of Dysmenorrhea: Impact on Life Course Potential

Dysmenorrhea is the most common gynecologic condition among the female population and has a significant impact on life course potential. It has a widespread impact on a female's mental and physical well-being, with longstanding impairments on quality of life, personal relationships, and education and career attainment. Furthermore, untreated dysmenorrhea can lead to hyperalgesic priming, which predisposes to chronic pelvic pain. Primary dysmenorrhea is pain in the lower abdomen that occurs before or during menses and in the absence of pelvic pathology. One possible mechanism is endometrial inflammation and increased prostaglandin release, resulting in painful uterine contractions. Dysmenorrhea may also occur secondary to pelvic pathology, such as endometriosis, adenomyosis or due to cyclic exacerbation of non-gynecologic pain conditions. A thorough patient evaluation is essential to differentiate between potential causes and guide management. Treatment must be tailored to individual patient symptoms. Pharmacologic management with non-steroidal anti-inflammatory medications and/or combined hormonal contraceptives is most common. Heat therapy, exercise, vitamins and dietary supplements have limited evidence and can be offered for patients seeking non-pharmacologic adjunctive or alternative options. Greater awareness for both health-care providers and patients allows for early intervention to reduce impact on quality of life and life course potential.

The genetic basis of endometriosis and comorbidity with other pain and inflammatory conditions

Endometriosis is a common condition associated with debilitating pelvic pain and infertility. A genome-wide association study meta-analysis, including 60,674 cases and 701,926 controls of European and East Asian descent, identified 42 genome-wide significant loci comprising 49 distinct association signals. Effect sizes were largest for stage 3/4 disease, driven by ovarian endometriosis. Identified signals explained up to 5.01% of disease variance and regulated expression or methylation of genes in endometrium and blood, many of which were associated with pain perception/maintenance (SRP14/BMF, GDAP1, MLLT10, BSN and NGF). We observed significant genetic correlations between endometriosis and 11 pain conditions, including migraine, back and multisite chronic pain (MCP), as well as inflammatory conditions, including asthma and osteoarthritis. Multitrait genetic analyses identified substantial sharing of variants associated with endometriosis and MCP/migraine. Targeted investigations of genetically regulated mechanisms shared between endometriosis and other pain conditions are needed to aid the development of new treatments and facilitate early symptomatic intervention.

Primary dysmenorrhoea in adolescents and young women: A twin family study of maternal transmission, genetic influence and associations

AIMS

The extent to which maternal transmission of primary dysmenorrhoea is genetically determined in adolescents and young women has yet to be determined. We aimed to assess heritability and associations relevant to primary pain syndromes using a twin family study.

METHODS

Participants were young menstruating female twins, and their oldest sisters and mothers, whose families were registered with Twins Research Australia and previously participated in a twin family study of primary paediatric pain disorders. Questionnaire packs were mailed, assessing current maximum and average menstrual pain intensity, current pain interference with activities and retrospective dysmenorrhea secondary symptoms.

RESULTS

The sample comprised 206 twin individuals (57 monozygous (MZ) and 46 dizygous (DZ) pairs) aged 10-22 years, eldest siblings (n = 38) aged 13-28 years and mothers (n = 101) aged 32-61 years. The estimated regression coefficient of the relationship between mother-daughter and twin-sibling dyads indicated significant associations for the measures of dysmenorrhea and supported heritability. Adjusted for age, the within twin-pair correlation for MZ twins was generally more than twice that of DZ twins. Heritability estimates were maximal pain intensity 0.67 (P = 3.8 × 10^-11 ), average pain intensity 0.63 (P = 3.7 × 10^-10 ), pain interference 0.57 (P = 1.8 × 10^-8 ) and retrospective symptoms 0.57 (P = 1.8 × 10^-8 ). Twin individuals with a lifetime (three-month) history of iron deficiency and those with painless restless legs syndrome (RLS) were significantly more likely to have more intense pain associated with menstruation.

CONCLUSION

Primary dysmenorrhea in adolescents and young women was shown to be relatively strongly genetically influenced and associated especially with a history of iron deficiency and painless RLS which have potential therapeutic implications.

Genome-wide association study of primary dysmenorrhea in the Taiwan Biobank validates associations near the NGF and IL1 gene loci

Using the Taiwan Biobank, we aimed to identify traits and genetic variations that could predispose Han Chinese women to primary dysmenorrhea. Cases of primary dysmenorrhea included those who self-reported "frequent dysmenorrhea" in a dysmenorrhea-related Taiwan Biobank questionnaire, and those who have been diagnosed with severe dysmenorrhea by a physician. Controls were those without self-reported dysmenorrhea. Customized Axiom-Taiwan Biobank Array Plates were used to perform whole-genome genotyping, PLINK was used to perform association tests, and HaploReg was used to conduct functional annotations of SNPs and bioinformatic analyses. The GWAS analysis included 1186 cases and 24,020 controls. We identified 53 SNPs that achieved genome-wide significance (P < 5 × 10^-8, which clustered in 2 regions. The first SNP cluster was on chromosome 1, and included 24 high LD (R² > 0.88) variants around the NGF gene (lowest P value of 3.83 × 10^-13 for rs2982742). Most SNPs occurred within NGF introns, and were predicted to alter regulatory binding motifs. The second SNP cluster was on chromosome 2, including 7 high LD (R² > 0.94) variants around the IL1A and IL1B loci (lowest P value of 7.43 × 10^-10 for rs11676014) and 22 SNPs that did not reach significance after conditional analysis. Most of these SNPs resided within IL1A and IL1B introns, while 2 SNPs may be in the promoter histone marks or promoter flanking regions of IL1B. To conclude, data from this study suggest that NGF, IL1A, and IL1B may be involved in the pathogenesis of primary dysmenorrhea in the Han Chinese in Taiwan.

Primary Dysmenorrhea: Pathophysiology, Diagnosis, and Treatment Updates

Primary dysmenorrhea (PD) is a common, disregarded, underdiagnosed, and inadequately treated complaint of both young and adult females. It is characterized by painful cramps in the lower abdomen, which start shortly before or at the onset of menses and which could last for 3 days. In particular, PD negatively impacts the quality of life (QOL) of young females and is the main reason behind their absenteeism from school or work. It is suggested that increased intrauterine secretion of prostaglandins F2α and E2 are responsible for the pelvic pain associated with this disorder. Its associated symptoms are physical and/or psychological. Its physical symptoms include headache, lethargy, sleep disturbances, tender breasts, various body pains, disturbed appetite, nausea, vomiting, constipation or diarrhea, and increased urination, whereas its psychological symptoms include mood disturbances, such as anxiety, depression, and irritability. While its diagnosis is based on patients’ history, symptoms, and physical examination, its treatment aims to improve the QOL through the administration of nonsteroidal anti-inflammatory drugs, hormonal contraceptives, and/or the use of non-pharmacological aids (e.g., topical heat application and exercise). Patients must be monitored to measure their response to treatment, assess their adherence, observe potential side effects, and perform further investigations, if needed.

Prevalence of dysmenorrhea and associated factors among students in Ethiopia: A systematic review and meta-analysis

BACKGROUND

Dysmenorrhea is one of the most common gynecological complaints among adolescent women. It has been associated with short-term absenteeism in school and has a negative impact on academic and daily activities. Therefore, the aim of the study was to show the evidence on the magnitude and correlates of dysmenorrhea in Ethiopia.

METHOD

In this systematic review and meta-analysis, we searched the literature from different databases such as PubMed/Medline, Science Direct, PsycINFO, and Cochrane library. We also used unpublished literature from Google, Google Scholar. The quality of the included articles was assessed using the Newcastle-Ottawa Scale. Data were extracted using a Microsoft Excel data extraction format. STATA version 14 statistical software was used for data analysis. To assess the heterogeneity of the primary articles, the Cochrane Q test statistics and the I² test were carried out. Publication bias was inspected by funnel plot, and Egger's test was performed to confirm the presence of publication bias. A random-effects meta-analysis was used to estimate the pooled prevalence of dysmenorrhea and its associated factors.

RESULT

A total of 12 studies were included in the final meta-analysis. The pooled prevalence estimate of dysmenorrhea among female students in Ethiopia is 71.69% (66.82%-76.56%). In our systematic review, among factors associated with dysmenorrhea, the family history of dysmenorrhea was frequently reported in included studies. Therefore, dysmenorrhea was significantly associated with a family history of dysmenorrhea (adjusted odds ratio = 4.69 (95% confidence interval: 2.80-7.85)).

CONCLUSION

The pooled prevalence estimate of dysmenorrhea among students was much higher in Ethiopia. Health professionals and teachers should educate and support students to follow their menstrual cycle regularly in the event of irregular periods. There should be an awareness of the negative consequences of dysmenorrhea to reduce the physical and psychological stresses that affect women and their families.

Sources of Individual Differences in Pain

Pain is an immense clinical and societal challenge, and the key to understanding and treating it is variability. Robust interindividual differences are consistently observed in pain sensitivity, susceptibility to developing painful disorders, and response to analgesic manipulations. This review examines the causes of this variability, including both organismic and environmental sources. Chronic pain development is a textbook example of a gene-environment interaction, requiring both chance initiating events (e.g., trauma, infection) and more immutable risk factors. The focus is on genetic factors, since twin studies have determined that a plurality of the variance likely derives from inherited genetic variants, but sex, age, ethnicity, personality variables, and environmental factors are also considered.

Prospective Association between Dysmenorrhea and Chronic Pain Development in Community-Dwelling Women

Despite emerging evidence of associations between dysmenorrhea, enhanced pain sensitivity, and functional neuroimaging patterns consistent with chronic pain, it is unknown whether dysmenorrhea is prospectively associated with chronic pain development. Gaining a better understanding of this relationship could inform efforts in prevention of chronic pain. Using data from the national Midlife in the United States cohort, we examined the prospective association between dysmenorrhea and chronic pain development during a 10-year follow-up (starting 10 years after dysmenorrhea was measured) among 874 community-dwelling women aged 25-74 at baseline (when dysmenorrhea was measured). We fit modified Poisson regression models adjusting for sociodemographic, lifestyle and psychosocial factors. Among women who were menstruating at baseline, self-reported dysmenorrhea was associated with a 41% greater (95% confidence interval [CI] = 6%-88%) risk of developing chronic pain. Women with dysmenorrhea also developed chronic pain in more body regions (≥3 regions vs 1-2 regions vs none, odds ratio [OR] = 1.77, 95% CI = 1.18-2.64) and experienced greater pain interference (high-interference vs low-interference vs none, OR = 1.73, 95% CI = 1.15-2.59). Among women who had stopped menstruation at baseline, we did not find evidence of an association between their history of dysmenorrhea and subsequent risk of chronic pain development. Results suggest dysmenorrhea may be a general risk factor for chronic pain development among menstruating women. PERSPECTIVE: This study supports the temporality of dysmenorrhea and chronic pain development in a national female sample. Dysmenorrhea was also associated with developing more widespread and disabling pain among women who were still menstruating. Early management of dysmenorrhea may reduce the development and severity of chronic pain in women, although further research is required to determine whether dysmenorrhea is a causal risk factor or a risk marker of chronic pain.

An update on the management of chronic pelvic pain in women

Chronic pelvic pain represents a major public health problem for women and impacts significantly on their quality of life. Yet it is under-researched and a challenge to manage. Women who suffer from chronic pelvic pain frequently describe their healthcare journey as long, via a variety of specialists and frustrating, with their pain often dismissed. Aetiological factors and associations are best conceptualised using the 'three P's' model of predisposing, precipitating and perpetuating factors. This integrates the numerous biological, psychological and social contributors to the complex, multifactorial nature of chronic pelvic pain. Overall management involves analgesia, hormonal therapies, physiotherapy, psychological approaches and lifestyle advice, which like other chronic pain conditions relies on a multidisciplinary team approach delivered by professionals experienced and trained in managing chronic pelvic pain.

Genome-wide association study identifies candidate loci associated with chronic pain and postherpetic neuralgia

BACKGROUND

Human twin studies and other studies have indicated that chronic pain has heritability that ranges from 30% to 70%. We aimed to identify potential genetic variants that contribute to the susceptibility to chronic pain and efficacy of administered drugs. We conducted genome-wide association studies (GWASs) using whole-genome genotyping arrays with more than 700,000 markers in 191 chronic pain patients and a subgroup of 89 patients with postherpetic neuralgia (PHN) in addition to 282 healthy control subjects in several genetic models, followed by additional gene-based and gene-set analyses of the same phenotypes. We also performed a GWAS for the efficacy of drugs for the treatment of pain.

RESULTS

Although none of the single-nucleotide polymorphisms (SNPs) were found to be genome-wide significantly associated with chronic pain (p ≥ 1.858 × 10^-7), the GWAS of PHN patients revealed that the rs4773840 SNP within the ABCC4 gene region was significantly associated with PHN in the trend model (nominal p = 1.638 × 10^-7). In the additional gene-based analysis, one gene, PRKCQ, was significantly associated with chronic pain in the trend model (adjusted p = 0.03722). In the gene-set analysis, several gene sets were significantly associated with chronic pain and PHN. No SNPs were significantly associated with the efficacy of any of types of drugs in any of the genetic models.

CONCLUSIONS

These results suggest that the PRKCQ gene and rs4773840 SNP within the ABCC4 gene region may be related to the susceptibility to chronic pain conditions and PHN, respectively.

Association between dysmenorrhea and chronic pain: a systematic review and meta-analysis of population-based studies

OBJECTIVE

The objective of the study was to synthesize the epidemiological findings for the associations between dysmenorrhea, including primary dysmenorrhea and endometriosis-associated dysmenorrhea and any chronic pain conditions, including chronic pelvic pain, and chronic nonpelvic pain.

DATA SOURCES

The data sources included PubMed, Embase, and CINAHL from inception to December 2019.

STUDY ELIGIBILITY CRITERIA

The study criteria included observational population-based studies in which the relationship between dysmenorrhea and the presence or severity of chronic pain was examined.

STUDY APPRAISAL AND SYNTHESIS METHODS

Each study was double coded and evaluated for bias based on the modified Newcastle and Ottawa Scale. Random-effect meta-analyses were conducted to quantify the associations between dysmenorrhea and the presence of chronic pelvic and nonpelvic pain.

RESULTS

Out of 9452 records, 32 studies were included, with 14 reporting associations between dysmenorrhea and chronic pelvic pain, and 20 for dysmenorrhea and chronic nonpelvic pain. Primary dysmenorrhea and endometriosis-associated dysmenorrhea were examined in 7 studies, respectively. More than 30% of the studies were categorized as poor quality, 56% as moderate, and 12.5% as high. Dysmenorrhea was positively associated with both the presence and severity of chronic pelvic and nonpelvic pain conditions. Based on 6689 women from 8 studies, those with chronic pelvic pain had 2.43 (95% confidence interval, 1.98-2.99, I², 42%) times the odds of having dysmenorrhea compared with those without. Based on 3750 women from 11 studies, those with chronic nonpelvic pain had 2.62 (95% confidence interval, 1.84-3.72, I², 72%) times the odds of having dysmenorrhea compared with those without. Overall, dysmenorrhea was associated with 2.50 (95% confidence interval, 2.02-3.10) times the odds of chronic pain, which did not differ by chronic pelvic vs chronic nonpelvic pain, community vs clinical populations, or different geographical regions.

CONCLUSIONS

Dysmenorrhea may be a general risk factor for chronic pain, although whether primary dysmenorrhea increases the risk for chronic pain is unclear. Given that adolescence is a sensitive period for neurodevelopment, elucidating the role of primary dysmenorrhea in pain chronicity in future longitudinal studies is important for preventing both chronic pelvic and nonpelvic pain.

Dysmenorrhea and Associated Factors among Polish Women: A Cross-Sectional Study

Purpose

The aim of the research was to conduct an assessment of the prevalence of dysmenorrhea and associated factors among Polish women. Patients and Methods. A cross-sectional study was conducted among Polish women using an online questionnaire. The mean age of the participants was 23 ± 4 years. Out of the total of 1,317 women who took part in the study, 1,127 were included in the analysis, and 190 were excluded due to incomplete answers. The questionnaire consisted of 19 questions that were grouped into three parts. The first concerned sociodemographic data such as age, weight, education, and residence (urban or rural). The second part of the questionnaire pertained to the factors of dysmenorrhea (premenstrual syndrome, age of menarche, and family history of dysmenorrhea.). In the third part, the women were asked about their diet, alcohol intake, cigarette smoking, and physical activity.

Results

Dysmenorrhea affected 94% of the interviewed women. Dysmenorrhea was most likely to occur among respondents whose mothers had a history of dysmenorrhea (p < 0.005). Significant relationship between the occurrence of dysmenorrhea among respondents and their sisters was also observed (p < 0.005). The prevalence of premenstrual syndrome (PMS) was significantly higher in women reporting dysmenorrhea (p < 0.005). Other significant factors associated with dysmenorrhea were age of menarche (p < 0.005), stress frequency (p=0.005), lack of physical activity (p=0.037), and self-esteem (p=0.042). However, in the respondents, no significant relationship was observed between dysmenorrhea and diet, smoking, body mass index, and alcohol intake.

Conclusion

The study points to the fact that the problem of dysmenorrhea affects many Polish women. Women with dysmenorrhea were characterized with a family history of dysmenorrhea, occurrence of PMS, early age of menarche, stressful lifestyle, lack of physical activity, and low self-esteem. We suggest that further assessment of factors contributing for dysmenorrhea among women is necessary.

Prevalence of primary dysmenorrhea, its intensity, impact and associated factors among female students' at Gondar town preparatory school, Northwest Ethiopia

BACKGROUND

Primary dysmenorrhea is defined as a crampy pain in the lower abdomen before or during the menstrual period in the absence of any pelvic pathology. It is the leading motherhood problem worldwide but there is limited evidence on the prevalence of primary dysmenorrhea in the study area as well in Ethiopia. Researching primary dysmenorrhea helps to focus on the treatment plan. The study aimed to assess the prevalence, intensity, impact, and associated factors of primary dysmenorrhea among female students at Gondar town preparatory school.

METHODS

A cross-sectional study design conducted among female students at Gondar town Preparatory School from May 1-10/2017. A total of 459 study participants were used. A simple random sampling technique was used to select study participants. A self-administered structured questionnaire was employed. Epi Info version 7 and SPSS version 20 were used for data entry and analysis respectively. A binary logistic regression model was computed. Variables having a p-value < 0.05 in the multivariate logistic regression model were considered as statistically significant.

RESULTS

A total of 459 female students participated in the study with a response rate of 96.29%. The prevalence of primary dysmenorrhea among female students was found to be 64.7% (95% CI; 60.2-69.2%). Around 61% reported moderate intensity of menstrual pain and 50.7% complain about lower abdominal pain. Sixty-five percent of study participants reported that absenteeism from school was the impact of menstrual pain. Having irregular monthly menstrual cycle (AOR = 1.70, 95% CI; 1.02, 2.84) and positive family history of dysmenorrhea (AOR = 5.19, 95% CI: 3.21, 8.37) were significantly associated with primary dysmenorrhea.

CONCLUSIONS

The prevalence of primary dysmenorrhea was found to be high. Having an irregular monthly menstrual cycle and a positive family history of dysmenorrhea were determinants of primary dysmenorrhea.

Mental health and primary dysmenorrhea: a systematic review

Several factors including demographic, reproductive, lifestyle, psychological and social factors can affect incidence and severity of primary dysmenorrhea. This study aimed to systematically review the psychological risk factors associated with primary dysmenorrhea. Embase, ISI web of knowledge, ProQuest, Science Direct, Scopus and PubMed central were searched using keywords related to risk factors and primary dysmenorrhea. Observational studies, published in English after 2000, focusing solely on psychological factors affecting primary dysmenorrhea were included. The search process retrieved 11,928 potential related articles. Thirty three articles met inclusion criteria and were assessed for final synthesis. The STROBE checklist was used to quality assessment of studies. Results of study showed that few studies had investigated relationship between dysmenorrhea and most psychological disorders. Most studies have investigated the relationship between dysmenorrhea and depression, anxiety, stress, alcohol abuse and somatic disorders. So, further studies are needed to investigate relation between most psychological disorders with primary dysmenorrhea. Significant relationship between some mental health components such as depression, anxiety and stress with primary dysmenorrhea shows the importance of psychological assessment before the choice of therapeutic methods. Also, the feasibility of designing and evaluating the effectiveness of the use of psychotherapy interventions for the treatment of primary dysmenorrhea as alternative therapies can be considered.

Prevalence, Wellbeing, and Symptoms of Dysmenorrhea among University Nursing Students in Greece

Dysmenorrhea (pain during menstruation) is one of the most common medical conditions among women of reproductive age. Dysmenorrhea has been studied around the world but not yet in Greece. The aim of the present study was to investigate the prevalence, characteristics, and impact of dysmenorrhea on the wellbeing (exercising, and social and academic functioning) among nursing students in Greece. A cross-sectional study of 637 nursing students was conducted by administering a questionnaire at a university in Athens. The prevalence of dysmenorrhea was 89.2% and the rate of severe intensity was 52.5%. Factors that were associated with severe dysmenorrhea were family history (p = 0.02), early menarche (p = 0.05) and menstruation duration (p = 0.05). Women with moderate and severe pain reported using pain relievers (non-steroidal anti-inflammatory drugs (NSAIDs), paracetamol etc., p < 0.0005). Finally, activities affected by severe pain were class attendance (p = 0.01), personal studying (p < 0.0005), exercising (p < 0.0005), and socializing (p < 0.0005). Exam attendance (p = 0.27) and clinical placement attendance (p = 0.48) were not affected by severe dysmenorrhea. Dysmenorrhea has a high prevalence among nursing students and seems to affect important aspects of wellbeing and academic performance when the pain intensity is severe. The present findings lay the foundation for further investigation of dysmenorrhea both in the Greek population and cross-culturally.

Genetic associations of perinatal pain and depression

Underlying genetic influences may affect perinatal pain, depression, or both. We investigated the role of 59 single-nucleotide polymorphisms on 20 quantitative traits measured in perinatal women. Moreover, 183 pregnant women (28–37 weeks’ gestation) were prospectively genotyped for single-nucleotide polymorphisms with known prior associations with either pain or depression in nonpregnant populations. Prenatal saliva samples were collected. Phenotypic data were gathered during prenatal, labor and delivery, and postpartum (six weeks and three months) periods, capturing labor pain, Edinburgh Postnatal Depression Score, and Brief Pain Inventories. Following quality control, genotypes were used as predictors and phenotypes as dependent variables in multiple linear regression analyses to detect associations. Three statistical models were tested: additive allele effects, deviation from dominant allele effects, and the joint test of both. rs4633 (a synonymous single-nucleotide polymorphism in COMT ) associated with “pain right now” scores at six weeks postpartum. Single-nucleotide polymorphisms rs1135349 (a single-nucleotide polymorphism within a small noncoding RNA that has many prior associations for depression) and rs7548151 (intronic in ASTN1 ) were associated with the maximum pain unpleasantness score experienced during labor (a measure of the emotional valence of labor pain), controlling for the Holm–Bonferroni family-wise error rate. Sensory dimensions of labor pain (i.e., pain intensity) and postpartum depression scores were not associated with genotyped single-nucleotide polymorphisms. Identifying genomic components of these perinatal complex disorders may produce insights into relevant pathways or novel treatment options.

Do MicroRNAs Modulate Visceral Pain?

Visceral pain, a common characteristic of multiple diseases relative to viscera, impacts millions of people worldwide. Although hundreds of studies have explored mechanisms underlying visceral pain, it is still poorly managed. Over the past decade, strong evidence emerged suggesting that microRNAs (miRNAs) play a significant role in visceral nociception through altering neurotransmitters, receptors and other genes at the posttranscriptional level. Under pathological conditions, one kind of miRNA may have several target mRNAs and several kinds of miRNAs may act on one target, suggesting complex interactions and mechanisms between miRNAs and target genes lead to pathological states. In this review we report on recent progress in examining miRNAs responsible for visceral sensitization and provide miRNA-based therapeutic targets for the management of visceral pain.

Japanese GWAS identifies variants for bust-size, dysmenorrhea, and menstrual fever that are eQTLs for relevant protein-coding or long non-coding RNAs

Traits related to primary and secondary sexual characteristics greatly impact females during puberty and day-to-day adult life. Therefore, we performed a GWAS analysis of 11,348 Japanese female volunteers and 22 gynecology-related phenotypic variables, and identified significant associations for bust-size, menstrual pain (dysmenorrhea) severity, and menstrual fever. Bust-size analysis identified significant association signals in CCDC170-ESR1 (rs6557160; P = 1.7 × 10-16) and KCNU1-ZNF703 (rs146992477; P = 6.2 × 10-9) and found that one-third of known European-ancestry associations were also present in Japanese. eQTL data points to CCDC170 and ZNF703 as those signals' functional targets. For menstrual fever, we identified a novel association in OPRM1 (rs17181171; P = 2.0 × 10-8), for which top variants were eQTLs in multiple tissues. A known dysmenorrhea signal near NGF replicated in our data (rs12030576; P = 1.1 × 10-19) and was associated with RP4-663N10.1 expression, a putative lncRNA enhancer of NGF, while a novel dysmenorrhea signal in the IL1 locus (rs80111889; P = 1.9 × 10-16) contained SNPs previously associated with endometriosis, and GWAS SNPs were most significantly associated with IL1A expression. By combining regional imputation with colocalization analysis of GWAS/eQTL signals along with integrated annotation with epigenomic data, this study further refines the sets of candidate causal variants and target genes for these known and novel gynecology-related trait loci.

[Definition, description, clinicopathological features, pathogenesis and natural history of endometriosis: CNGOF-HAS Endometriosis Guidelines]

Endometriosis and adenomyosis are histologically defined. The frequency of endometriosis cannot be precisely estimated in the general population. Endometriosis is considered a disease when it causes pain and/or infertility. Endometriosis is a heterogeneous disease with three well-recognized subtypes that are often associated with each other: superficial endometriosis (SUP), ovarian endometrioma (OMA), and deep infiltrating endometriosis (DIE). DIE is frequently multifocal and mainly affects the following structures: the uterosacral ligaments, the posterior vaginal cul-de-sac, the bladder, the ureters, and the digestive tract (rectum, recto-sigmoid junction, appendix). The role of menstrual reflux in the pathophysiology of endometriosis is major and explains the asymmetric distribution of lesions, which predominate in the posterior compartment of the pelvis and on the left (NP3). All factors favoring menstrual reflux increase the risk of endometriosis (early menarche, short cycles, AUB, etc.). Inflammation and biosteroid hormones synthesis are the main mechanisms favoring the implantation and the growth of the lesions. Pain associated with endometriosis can be explained by nociception, hyperalgia, and central sensitization, associated to varying degrees in a single patient. Typology of pain (dysmenorrhea, deep dyspareunia, digestive or urinary symptoms) is correlated with the location of the lesions. Infertility associated with endometriosis can be explained by several non-exclusive mechanisms: a pelvic factor (inflammation), disrupting natural fertilization; an ovarian factor, related to oocyte quality and/or quantity; a uterine factor disrupting implantation. The pelvic factor can be fixed by surgical excision of the lesions that improves the chance of natural conception (NP2). The uterine factor can be corrected by an ovulation-blocking treatment that improves the chances of getting pregnant by in vitro fertilization (NP2). The impact of endometrioma exeresis on the ovarian reserve (NP2) should be considered when a surgery is scheduled. Endometriosis is a multifactorial disease, resulting from combined action of genetic and environmental factors. The risk of developing endometriosis for a first-degree relative is five times higher than in the general population (NP2). Identification of genetic variants involved in the disease has no implication for clinical practice for the moment. The role of environmental factors, particularly endocrine disrupters, is plausible but not demonstrated. Literature review does not support the progression of endometriosis over time, either in terms of the volume or the number of the lesions (NP3). The risk of acute digestive occlusion or functional loss of a kidney in patients followed for endometriosis seems exceptional. These complications were revealing the disease in the majority of cases. IVF does not increase the intensity of pain associated with endometriosis (NP2). There is few data on the influence of pregnancy on the lesions, except the possibility of a decidualization of the lesions that may give them a suspicious aspect on imaging. The impact of endometriosis on pregnancy is debated. There is an epidemiological association between endometriosis and rare subtypes of ovarian cancer (endometrioid and clear cell carcinomas) (NP2). However, the relative risk is moderate (around 1.3) (NP2) and the causal relationship between endometriosis and ovarian cancer is not demonstrated so far. Considering the low incidence of endometriosis-associated ovarian cancer, there is no argument to propose a screening or a risk reducing strategy for the patients.

Symptoms-Based Phenotypes Among Women With Dysmenorrhea: A Latent Class Analysis

Dysmenorrhea is highly prevalent and may increase women's risk for developing other chronic pain conditions. Although it is highly variable, symptom-based dysmenorrhea phenotypes have not been identified. The aims of the study were to identify symptom-based dysmenorrhea phenotypes and examine their relationships with demographic and clinical characteristics. In a cross-sectional study, 762 women with dysmenorrhea rated severity of 14 dysmenorrhea-related symptoms. Using latent class analysis, we identified three distinctive phenotypes. Women in the "mild localized pain" phenotype ( n = 202, 26.51%) had mild abdominal cramps and dull abdominal pain/discomfort. Women in the "severe localized pain" phenotype ( n = 412, 54.07%) had severe abdominal cramps. Women in the "multiple severe symptoms" phenotype ( n = 148, 19.42%) had severe pain at multiple locations and multiple gastrointestinal symptoms. Race, ethnicity, age, and comorbid chronic pain conditions were significantly associated with phenotypes. Identification of these symptom-based phenotypes provides a foundation for research examining genotype-phenotype associations, etiologic mechanisms, and/or variability in treatment responses.

Common variants in ZMIZ1 and near NGF confer risk for primary dysmenorrhoea

Primary dysmenorrhoea, defined as painful menstrual cramps in the absence of pelvic pathology, is a common problem in women of reproductive age. Its aetiology and pathophysiology remain largely unknown. Here we performed a two-stage genome-wide association study and subsequent replication study to identify genetic factors associated with primary dysmenorrhoea in a total of 6,770 Chinese individuals. Our analysis provided evidence of a significant (P<5 × 10⁻⁸) association at rs76518691 in the gene ZMIZ1 and at rs7523831 near NGF. ZMIZ1 has previously been associated with several autoimmune diseases, and NGF plays a key role in the generation of pain and hyperalgesia and has been associated with migraine. These findings provide future directions for research on susceptibility mechanisms for primary dysmenorrhoea. Furthermore, our genetic architecture analysis provides molecular support for the heritability and polygenic nature of this condition.

Primary dysmenorrhoea, the most common gynaecologic complaint, remains genetically and pathophysiologically elusive. Here, Li and colleagues identify common variants in ZMIZ1 and near NGF conferring risk for primary dysmenorrhoea using genome-wide association study in a Chinese population.

Genome-wide association study suggests common variants within RP11-634B7.4 gene influencing severe pre-treatment pain in head and neck cancer patients

Pain is often one of the first signs of squamous cell carcinoma of the head and neck (HNSCC). Pain at diagnosis is an important prognostic marker for the development of chronic pain, and importantly, for the overall survival time. To identify variants influencing severe pre-treatment pain in 1,368 patients newly diagnosed with HNSCC, we conducted a genome-wide association study based on 730,525 tagging SNPs. The patients were all previously untreated for cancer. About 15% of the patients had severe pre-treatment pain, defined as pain score ≥7 (0 = “no pain” and 10 = “worst pain”). We identified 3 common genetic variants in high linkage disequilibrium for severe pre-treatment pain, representing one genomic region at 1q44 (rs3862188, P = 3.45 × 10⁻⁸; rs880143, P = 3.45 × 10⁻⁸; and rs7526880, P = 4.92 × 10⁻⁸), which maps to the RP11-634B7.4 gene, a novel antisense gene to three olfactory receptor genes. Olfactory receptor genes, upstream effectors of the MAPK signaling cascade, might be novel target genes for pain in HNSCC patients. Future experimental validation to explore biological mechanisms will be key to defining the role of the intronic variants and non-coding RNA for pain in patients with HNSCC.