The relation between menarche and the age of first symptoms in a multiple sclerosis cohort

Women's Health and Pregnancy in Multiple Sclerosis

Multiple sclerosis has a 3:1 female-to-male predominance and commonly presents in young adult women. The hormonal changes in women throughout their lifetime do affect the underlying pathology of multiple sclerosis, and the needs of women therefore change with age. Although multiple sclerosis does not adversely affect fertility or pregnancy, there are many factors to consider when caring for women throughout family planning, pregnancy, and the postpartum period. The care of these women and complex decisions regarding disease-modifying therapy use in family planning should be individualized and comprehensive.

The impact of menopause on multiple sclerosis

Menopause, defined as the permanent cessation of ovarian function, represents a period of significant fluctuation in sex hormone concentrations. Sex hormones including oestrogen, progesterone, testosterone and anti-Mullerian hormone are thought have neuroinflammatory effects and are implicated in both neuroprotection and neurodegeneration. Sex hormones are thought to have a role in modifying clinical trajectory in multiple sclerosis (MS) throughout the lifespan. Multiple sclerosis predominantly effects women and is typically diagnosed early in a woman's reproductive life. Most women with MS will undergo menopause. Despite this, the effect of menopause on MS disease course remains unclear. This review examines the relationship between sex hormones and MS disease activity and clinical course, particularly around the time of menopause. It will consider the role of interventions such as exogenous hormone replacement therapy in modulating clinical outcomes in this period. Understanding the impact of menopause on multiple sclerosis is fundamental for delivering optimal care to women with MS as they age and will inform treatment decisions with the aim of minimising relapses, disease accrual and improving quality of life.

Neuroimmunological Disorders

Multiple sclerosis is a disease that tends to affect women during their childbearing years. Although relapse risk decreases during pregnancy, patients should still be optimized on disease-modifying therapy before and after pregnancy to minimize gaps in treatment. Exclusive breastfeeding may reduce the chances of disease relapse postpartum, and many disease-modifying therapies are considered to be safe while breastfeeding. Treatments for other neuroimmunologic disorders such as neuromyelitis optica spectrum disorder, myelin oligodendrocyte glycoprotein antibody-associated disease, neurosarcoidosis, and central nervous system vasculitis may require rituximab before and prednisone or intravenous immunoglobulin therapy during pregnancy.

Sex Hormones as Key Modulators of the Immune Response in Multiple Sclerosis: A Review

BACKGROUND

A variety of autoimmune diseases, including MS, amplify sex-based physiological differences in immunological responsiveness. Female MS patients experience pathophysiological changes during reproductive phases (pregnancy and menopause). Sex hormones can act on immune cells, potentially enabling them to modify MS risk, activity, and progression, and to play a role in treatment.

METHODS

Scientific papers (published between 1998 and 2021) were selected through PubMed, Google Scholar, and Web of Science literature repositories. The search was limited to publications analyzing the hormonal profile of male and female MS patients during different life phases, in particular focusing on sex hormone treatment.

RESULTS

Both men and women with MS have lower testosterone levels compared to healthy controls. The levels of estrogens and progesterone increase during pregnancy and then rapidly decrease after delivery, possibly mediating an immune-stabilizing process. The literature examined herein evidences the neuroprotective effect of testosterone and estrogens in MS, supporting further examinations of their potential therapeutic uses.

CONCLUSIONS

A correlation has been identified between sex hormones and MS clinical activity. The combination of disease-modifying therapies with estrogen or estrogen plus a progestin receptor modulator promoting myelin repair might represent an important strategy for MS treatment in the future.

Sex and gender differences in autoimmune demyelinating CNS disorders: Multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD) and myelin-oligodendrocyte-glycoprotein antibody associated disorder (MOGAD)

Multiple sclerosis (MS), Neuromyelitis optica spectrum disorder (NMOSD) and Myelin-Oligodendrocyte-Glycoprotein antibody associated disorder (MOGAD) are demyelinating disorders of the central nervous system (CNS) of autoimmune origin. Here, we summarize general considerations on sex-specific differences in the immunopathogenesis and hormonal influences as well as key clinical and epidemiological elements. Gender-specific issues are widely neglected starting with the lacking separation of sex as a biological variable and gender comprising the sociocultural components. As for other autoimmune diseases, female preponderance is common in MS and NMOSD. However, sex distribution in MOGAD seems equal. As in MS, immunotherapy in NMOSD and MOGAD is crucial to prevent further disease activity. Therefore, we assessed data on sex differences of the currently licensed disease-modifying treatments for efficacy and safety. This topic seems widely neglected with only fragmented information resulting from post-hoc analyses of clinical trials or real-world post-marketing studies afflicted with lacking power and/or inherent sources of bias. In summary, biological hypotheses of sex differences including genetic factors, the constitution of the immune system and hormonal influences are based upon human and preclinical data, especially for the paradigmatic disease of MS whereas specific data for NMOSD and MOGAD are widely lacking. Epidemiological and clinical differences between men and women are well described for MS and to some extent for NMOSD, yet, with remaining contradictory findings. MOGAD needs further detailed investigation. Sex-specific analyses of safety and efficacy of long-term immunotherapies need to be addressed in future studies designed and powered to answer the pressing questions and to optimize and individualize treatment.

A Case of Double Standard: Sex Differences in Multiple Sclerosis Risk Factors

Multiple sclerosis is a complex, multifactorial, dysimmune disease prevalent in women. Its etiopathogenesis is extremely intricate, since each risk factor behaves as a variable that is interconnected with others. In order to understand these interactions, sex must be considered as a determining element, either in a protective or pathological sense, and not as one of many variables. In particular, sex seems to highly influence immune response at chromosomal, epigenetic, and hormonal levels. Environmental and genetic risk factors cannot be considered without sex, since sex-based immunological differences deeply affect disease onset, course, and prognosis. Understanding the mechanisms underlying sex-based differences is necessary in order to develop a more effective and personalized therapeutic approach.

The role of sex hormones in women with multiple sclerosis: From puberty to assisted reproductive techniques

BACKGROUND

Multiple Sclerosis is a multifactorial chronic autoimmune disease, affecting predominantly females in the fertile age. Sex hormones changes during a woman's life, from puberty to menopause, including pregnancy and puerperium, may influence the onset and course of Multiple Sclerosis. The effect of estrogen levels on immune, clinical and radiological aspects of Multiple Sclerosis, also stimulated investigation on the effect of sexual hormones therapies, such as oral contraceptives and assisted reproductive technique, on the Multiple Sclerosis course.

SEARCH STRATEGY AND SELECTION CRITERIA

A literature search for original articles and reviews was conducted in the databases, including PubMed, Scopus, and ClinicalTrials.gov of the U.S. National Library of Medicine site from 1988 to 2020.

RESULTS AND CONCLUSION

This review reports the effects of the physiological and iatrogenic hormonal changes either on immune or clinical or paraclinical features in the different life stages of women affected by Multiple Sclerosis.

Reproductive history and progressive multiple sclerosis risk in women

Being a woman is one of the strongest risk factors for multiple sclerosis. The natural reproductive period from menarche to natural menopause corresponds to the active inflammatory disease period in multiple sclerosis. The fifth decade marks both the peri-menopausal transition in the reproductive aging and a transition from the relapsing-remitting to the progressive phase in multiple sclerosis. A short reproductive period with premature/early menopause and/or low number of pregnancies may be associated with an earlier onset of the progressive multiple sclerosis phase. A cross-sectional study of survey-based reproductive history in a multiple sclerosis clinical series enriched for patients with progressive disease, and a case–control study of multiple sclerosis and age/sex matched controls from a population-based cohort were conducted. Menarche age, number of complete/incomplete pregnancies, menopause type and menopause age were compared between 137 cases and 396 control females. Onset of relapsing-remitting phase of multiple sclerosis, progressive disease onset and reaching severe disability (expanded disability status scale 6) were studied as multiple sclerosis-related outcomes (n = 233). Menarche age was similar between multiple sclerosis and control females (P = 0.306). Females with multiple sclerosis had fewer full-term pregnancies than the controls (P < 0.001). Non-natural menopause was more common in multiple sclerosis (40.7%) than in controls (30.1%) (P = 0.030). Age at natural menopause was similar between multiple sclerosis (median, interquartile range: 50 years, 48–52) and controls (median, interquartile range: 51 years, 49–53) (P = 0.476). Nulliparous females had earlier age at progressive multiple sclerosis onset (mean ± standard deviation: 41.9 ± 12.5 years) than females with ≥1 full-term pregnancies (mean ± standard deviation: 47.1 ± 9.7 years) (P = 0.069) with a pregnancy-dose effect [para 0 (mean ± standard deviation: 41.9 ± 12.5 years), para 1–3 (mean ± standard deviation: 46.4 ± 9.2 years), para ≥4 (mean ± standard deviation: 52.6 ± 12.9 years) (P = 0.005)]. Menopause age was associated with progressive multiple sclerosis onset age (R² = 0.359, P < 0.001). Duration from onset of relapses to onset of progressive multiple sclerosis was shorter for females with premature/early menopause (n = 26; mean ± standard deviation: 12.9 ± 9.0 years) than for females with normal menopause age (n = 39; mean ± standard deviation: 17.8 ± 10.3 years) but was longer than for males (mean  ±standard deviation: 10.0 ± 9.4 years) (P = 0.005). There was a pregnancy-dose effect of age at expanded disability status scale 6 (para 0: 43.0 ± 13.2 years, para 1–3: 51.7 ± 11.3 years, para ≥4: 53.5 ± 4.9 years) (P = 0.013). Age at menopause was associated with age at expanded disability status scale 6 (R² = 0.229, P < 0.003). Premature/early menopause or nulliparity was associated with earlier onset of progressive multiple sclerosis with a ‘dose effect’ of pregnancies on delaying progressive multiple sclerosis and severe disability. Although causality remains uncertain, our results suggest a beneficial impact of oestrogen in delaying progressive multiple sclerosis. If confirmed in prospective studies, our findings have implications for counselling women with multiple sclerosis about pregnancy, surgical menopause and menopausal hormone therapy.

Sex effects across the lifespan in women with multiple sclerosis

Multiple sclerosis (MS) is an autoimmune inflammatory demyelinating central nervous system disorder that is more common in women, with onset often during reproductive years. The female:male sex ratio of MS rose in several regions over the last century, suggesting a possible sex by environmental interaction increasing MS risk in women. Since many with MS are in their childbearing years, family planning, including contraceptive and disease-modifying therapy (DMT) counselling, are important aspects of MS care in women. While some DMTs are likely harmful to the developing fetus, others can be used shortly before or until pregnancy is confirmed. Overall, pregnancy decreases risk of MS relapses, whereas relapse risk may increase postpartum, although pregnancy does not appear to be harmful for long-term prognosis of MS. However, ovarian aging may contribute to disability progression in women with MS. Here, we review sex effects across the lifespan in women with MS, including the effect of sex on MS susceptibility, effects of pregnancy on MS disease activity, and management strategies around pregnancy, including risks associated with DMT use before and during pregnancy, and while breastfeeding. We also review reproductive aging and sexual dysfunction in women with MS.

Age at menarche and risk of multiple sclerosis (MS): a systematic review and meta-analysis

BACKGROUND

Some studies have looked at the age at menarche and risk of Multiple Sclerosis (MS).We aimed to conduct a systematic review and meta-analysis to estimate a pooled odds ratio of developing MS by increasing age at menarche.

METHODS

We searched PubMed, Scopus, EMBASE, CINAHL, Web of Science, Ovid, google scholar and gray literature (references of references, congress abstracts) up to 10th April 2019.

RESULTS

The literature search found 312 articles. After eliminating duplicates, reviews, case reports and trials, 18 articles remained. Three articles were ultimately included in the final analysis. Two studies were from Iran, and one from Canada. The pooled odds ratio (OR) for increasing 1 year of age at menarche was 0.88 (95% CI:0.82-0.94), with no significant heterogeneity (I2 = 49%, p = 0.1). Mean age at menarche was significantly different between case and control groups (mean difference = - 0.22, 95% CI = -0.42,-0.02).

CONCLUSION

The result of this systematic review showed that the risk of MS decreases by increasing age at menarche.

Menarche, pregnancies, and breastfeeding do not modify long-term prognosis in multiple sclerosis

OBJECTIVE

To investigate the effect of menarche, pregnancies, and breastfeeding on the risk of developing multiple sclerosis (MS) and disability accrual using a multivariate approach based on a large prospective cohort of patients with clinically isolated syndrome (CIS).

METHODS

A cross-sectional survey of the reproductive information of female participants in a CIS cohort was performed. We examined the relationship of age at menarche with the risk of clinically definite MS (CDMS), McDonald 2010 MS, and Expanded Disability Status Scale (EDSS) 3.0 and 6.0. The effect of pregnancy (before and after CIS) and breastfeeding in the risk of CDMS, McDonald 2010 MS, and EDSS 3.0 was also examined. Univariate and multivariate analyses were performed and findings were confirmed using sensitivity analyses and a propensity score model.

RESULTS

The data of 501 female participants were collected. Age at menarche did not correlate with age at CIS and was not associated with the risk of CDMS or EDSS 3.0 or 6.0. Pregnancy before CIS was protective for CDMS in the univariate analysis, but the effect was lost in the multivariate model and did not modify the risk of EDSS 3.0. Pregnancy after CIS was protective for both outcomes in univariate and multivariate analyses when pregnancy was considered a baseline variable, but the protective effect disappeared when analyzed as a time-dependent event. Breastfeeding did not modify the risk for the 3 outcomes.

CONCLUSIONS

These results demonstrate that menarche, pregnancies, and breastfeeding did not substantially modify the risk of CDMS or disability accrual using a multivariable and time-dependent approach.

Impact of sex hormones on immune function and multiple sclerosis development

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS) affecting young people and leading to demyelination and neurodegeneration. The disease is clearly more common in women, in whom incidence has been rising. Gender differences include: earlier disease onset and more frequent relapses in women; and faster progression and worse outcomes in men. Hormone-related physiological conditions in women such as puberty, pregnancy, puerperium, and menopause also exert significant influence both on disease prevalence as well as on outcomes. Hormonal and/or genetic factors are therefore believed to be involved in regulating the course of disease. In this review, we discuss clinical evidence for the impact of sex hormones (estrogens, progesterone, prolactin, and testosterone) on MS and attempt to elucidate the hormonal and immunological mechanisms potentially underlying these changes. We also review current knowledge on the relationship between sex hormones and resident CNS cells and provide new insights in the context of MS. Understanding these molecular mechanisms may contribute to the development of new and safer treatments for both men and women.

Age at Menarche and Risk of Multiple Sclerosis: Current Progress From Epidemiological Investigations

Multiple sclerosis (MS) is a chronic autoimmune inflammatory disorder of the brain and spinal cord in which focal lymphocytic infiltration leads to the damage of myelin and axons. As a multi-factorial complex trait, both genetic background and environmental factors are involved in MS etiology. The disease is more prevalent among women, and an overall female-to-male sex ratio of around 3 is usually reported. The fact that the female preponderance is only apparent among patients with disease onset after age 12 points toward a role of puberty in MS. A key marker of female pubertal development is menarche, however, evidence from previous epidemiological investigations has been sparse and conflicting: although some studies have linked earlier age at menarche (AAM) to an increased risk of MS, others have found no association or an inverse association. Understanding the effect of AAM in MS could increase our knowledge to the disease etiology, as well as deliver meaningful implication to patients' care by aiding clinical diagnosis. Therefore, we reviewed all the currently available epidemiological studies conducted for AAM and risk of MS in adult human populations. We found evidence supporting a possible favorable role of late AAM on MS risk, but this should be further confirmed by well-designed large-scale epidemiological studies and meta-analysis. Future work may be focused on Mendelian randomization analysis incorporating genetic markers to provide additional evidence of a putative causal relationship between AAM and MS. More work should be conducted for non-European populations to increase generalizability, and among the males to complementary with results from females. Future work may also be conducted focusing on hormonal reproductive factors other than menarche, and their effects in MS prognosis, severity, and drug response.

Neuromyelitis optica spectrum disorder and menstruation

BACKGROUND

Gender issues and the female preponderance in neuromyelitis optica spectrum disorder (NMOSD) have been investigated before, yet the interplay between NMOSD and menstrual characteristics has remained unknown. Thus, the aim was to compare menstrual cycle patterns and their symptoms in NMOSD patients and healthy women.

METHODS

This cross-sectional study was conducted during 2015-2016 in Isfahan, Iran, and included female patients aged>14years with a diagnosis of NMOSD and healthy subjects as controls. Data regarding age at menarche, menstrual characteristics, history of premenstrual syndrome (PMS) and possible perimenstrual symptoms were collected. Also, NMOSD patients were asked to report changes in their menstrual cycles after onset of the disorder.

RESULTS

The final study population included 32 NMOSD and 33 healthy controls. These groups did not differ regarding their demographics (P>0.05), and age at menarche in the NMOSD and control groups was 13.31±1.49 years and 13.48±1.44 years, respectively (P=0.637). The controls experienced PMS more frequently (78.8% vs. 40.6% in the NMOSD patients; P=0.03), with no significant differences in other menstrual features between groups (P>0.05). However, changes in menstruation after NMOSD onset were reported by 43.8% of patients, with an increase in menstrual irregularities from 15.6% to 43.7% (P=0.012); other menstrual characteristics did not differ after disease onset (P>0.05).

CONCLUSION

Menstruation do not differ between healthy controls and NMOSD patients before the onset of disease whereas, after its onset, those affected experienced more irregularities in their menstrual cycles. This may be an effect of NMOSD and its underlying disorders on menstruation and suggests that further interventions may be required for affected women.

Caring for Women with Multiple Sclerosis Across the Lifespan

PURPOSE OF REVIEW

Caring for women with multiple sclerosis (MS), whose first symptoms typically begin during the childbearing years, requires a comprehensive approach to management across a range of reproductive exposures, and beyond through menopause.

RECENT FINDINGS

This article summarizes what is known about the disease course in women with MS, how it differs from men, and the current state of knowledge regarding effects of reproductive exposures (menarche, childbearing, menopause) on MS-related inflammation and neurodegeneration. Recent findings regarding pregnancy-associated relapses in the treatment era, protective effects of breastfeeding, and care for women during the menopausal transition are reviewed. Then, updated recommendations to guiding women during childbearing-including pre-conception counseling, discontinuation of MS therapies, and management of postpartum relapses-are provided. Whenever possible, areas of uncertainty and avenues for future research are highlighted. From childhood through the postreproductive life stages, gender and hormonal exposures appear to shape an individual's risk for MS, as well as the experience of living with MS.

Uncovering the link between reproductive factors and multiple sclerosis: A case-control study on Iranian females

BACKGROUND

Increase of MS prevalence in females compared to males, especially in reproductive age, highlights the important role of reproductive factors in MS pathology.

OBJECTIVES

We examined the association between females' reproductive age-related factors and MS risk.

METHODS

A case-control study including 399 cases and 541 controls was carried out. The adjusted associations between MS risk and reproductive variables including age at menarche, oral contraceptive pills (OCPs) use history, OCP usage duration and age at first use, history of assisted reproductive technologies (ARTs) use, parity history, age at first childbirth and the number of parities, abortion and exclusive breast feeding > 2 months were assessed.

RESULTS

We found protective relationships between MS and older age at menarche (OR = 0.90 {95% CI = 0.82-0.98}), ART use history (OR = 0.45 {95% CI = 0.21-0.99}), older maternal age at first childbirth (OR = 0.94{95% CI = 0.89 - 0.99}) and higher number of parities(OR = 0.61 {95% CI = 0.49 - 0.75), whereas using OCPs was associated with higher risk of developing MS (OR = 1.80 {95% CI = 1.35-2.41}).

CONCLUSIONS

Links were noted between a number of reproductive factors and risk of MS.

Why monkeys do not get multiple sclerosis (spontaneously): An evolutionary approach

The goal of this review is to apply an evolutionary lens to understanding the origins of multiple sclerosis (MS), integrating three broad observations. First, only humans are known to develop MS spontaneously. Second, humans have evolved large brains, with characteristically large amounts of metabolically costly myelin. This myelin is generated over long periods of neurologic development—and peak MS onset coincides with the end of myelination. Third, over the past century there has been a disproportionate increase in the rate of MS in young women of childbearing age, paralleling increasing westernization and urbanization, indicating sexually specific susceptibility in response to changing exposures. From these three observations about MS, a life history approach leads us to hypothesize that MS arises in humans from disruption of the normal homeostatic mechanisms of myelin production and maintenance, during our uniquely long myelination period. This review will highlight under-explored areas of homeostasis in brain development, that are likely to shed new light on the origins of MS and to raise further questions about the interactions between our ancestral genes and modern environments.

Hormones and MS: Risk factors, biomarkers, and therapeutic targets

Sex differences in epidemiological, clinical, and pathological features of multiple sclerosis (MS) have been observed for decades, establishing a foundation for more recent progress in our understanding of their overall impact on the disease. In the ACTRIMS session on Hormones, Sex Chromosomes, and MS: Risk Factors, Biomarkers, and Therapeutic Targets, this progress was summarized in three presentations by pioneers in the field, revealing evidence that sex chromosomes, epigenetic factors, and sex hormones function as interactive determinants of disease risk and phenotype in a fashion dependent upon life stage, from prenatal development, childhood, and adolescence to adulthood and aging. Implications for the effects of puberty, pregnancy, menopause, and andropause on autoimmune and neurodegenerative mechanisms were discussed, along with potential applications of exogenous hormones. Although several limitations in current approaches and concepts were noted, current insights pave the way for future progress in our understanding of this enigmatic disease

Effect of puberty on multiple sclerosis risk and course

Puberty occurs over several years and is a time of major sex hormone changes. These changes impact many physiological functions including immune system maturation. This review details the current understanding of the impact of puberty on the risk to develop multiple sclerosis (MS) and the age at which it occurs, as well as its effect on the risk of relapses.

Breastfeeding, ovulatory years, and risk of multiple sclerosis

OBJECTIVE

To determine whether women who breastfeed their infants longer or have fewer ovulatory years are at lower risk of developing multiple sclerosis (MS).

METHODS

We recruited women with newly diagnosed MS or its precursor, clinically isolated syndrome (CIS) (n = 397), and matched controls (n = 433) into the MS Sunshine Study from the membership of Kaiser Permanente Southern California. A structured in-person questionnaire was administered to collect the behavioral (pregnancies, breastfeeding, hormonal contraceptive use) and biological (age at menarche and menopause, amenorrhea) factors to make up ovulatory years.

RESULTS

Among women who had live births, a cumulative duration of breastfeeding for ≥15 months was associated with a reduced risk of MS/CIS (adjusted odds ratio [OR] 0.47, 95% confidence interval [CI] 0.28-0.77; p = 0.003 compared to 0-4 months of breastfeeding). Being ≥15 years of age at menarche was also associated with a lower risk of MS/CIS (adjusted OR 0.56, 95% CI 0.33-0.96; p = 0.035). Total ovulatory years and the remaining factors that determine it, including gravidity, parity, episodes of amenorrhea, and hormonal contraceptive use, as well as age at first birth, showed no significant association with the risk of MS/CIS.

CONCLUSIONS

Mothers who breastfeed longer may be at lower subsequent risk of developing multiple sclerosis. This is consistent with the other known maternal health benefits of breastfeeding and with our previous observation that women with MS who breastfeed exclusively are at lower risk of postpartum relapses.

Female hormonal exposures and neuromyelitis optica symptom onset in a multicenter study

Objective:

To study the association between hormonal exposures and disease onset in a cohort of women with neuromyelitis optica spectrum disorder (NMOSD).

Methods:

Reproductive history and hormone use were assessed using a standardized reproductive survey administered to women with NMOSD (82% aquaporin-4 antibody positive) at 8 clinical centers. Using multivariable regression, we examined the association between reproductive exposures and age at first symptom onset (FS).

Results:

Among 217 respondents, the mean age at menarche was 12.8 years (SD 1.7). The mean number of pregnancies was 2.1 (SD 1.6), including 0.3 (SD 0.7) occurring after onset of NMOSD symptoms. In the 117 participants who were postmenopausal at the time of the questionnaire, 70% reported natural menopause (mean age: 48.9 years [SD 3.9]); fewer than 30% reported systemic hormone therapy (HT) use. Mean FS age was 40.1 years (SD 14.2). Ever-use of systemic hormonal contraceptives (HC) was marginally associated with earlier FS (39 vs 43 years, p = 0.05). Because HC use may decrease parity, when we included both variables in the model, the association between HC use and FS age became more significant (estimate = 2.7, p = 0.007). Among postmenopausal participants, 24% reported NMOSD onset within 2 years of (before or after) menopause. Among these participants, there was no association between age at menopause or HT use and age at NMOSD onset.

Conclusions:

Overall, age at NMOSD onset did not show a strong relationship with endogenous hormonal exposures. An earlier onset age did appear to be marginally associated with systemic HC exposure, an association that requires confirmation in future studies.

Risk factors of early onset of MS in women in reproductive age period: survival analysis approach

The incidence of multiple sclerosis (MS) has doubled in over the last decades in women, whereas it has been almost unchanged in men. The purpose of this study was to investigate the risk factors of early onset multiple sclerosis in women during reproductive years. A retrospective longitudinal study conducted on 200 women aged 15 to 50 years with MS, registered by the MS Society in Isfahan. Data gathering was fulfilled by standard questionnaire including variables about reproductive period, demographic characteristics, and history of diseases. Kaplan-Mayer with log-rank test and Cox regression models were used in predicting of the age of effective factors in onset of MS. P values less than 0.05 were considered statistically significant. The mean age of studied women was 31.77 ± 8.13 years and the mean and median age of onset the symptoms of MS was 26.79 ± 7.77 and 26 years, respectively. Based on the cox results occurring menarche at 15 years and higher increase the risk of MS 2.8-fold than those their menarche occurred at 12 years and lower (HR: 2.81, 95 % CI; 1.58-4.98).In addition, having only one pregnancy is related to higher risk of MS than other parities and increase the risk of MS 4.5-fold comparing to without parities. Age of menarche and parity numbers was the most important reproductive factors of MS in women. Nevertheless, history of autoimmune diseases, animal bite, childhood disease, family history of MS, regional area (tropical), and living in rural area were not related to early onset of MS.

Complex relation of HLA-DRB1*1501, age at menarche, and age at multiple sclerosis onset

OBJECTIVE

To examine the relationship between 2 markers of early multiple sclerosis (MS) onset, 1 genetic (HLA-DRB1*1501) and 1 experiential (early menarche), in 2 cohorts.

METHODS

We included 540 white women with MS or clinically isolated syndrome (N = 156 with genetic data available) and 1,390 white women without MS but with a first-degree relative with MS (Genes and Environment in Multiple Sclerosis [GEMS]). Age at menarche, HLA-DRB1*1501 status, and age at MS onset were analyzed.

RESULTS

In both cohorts, participants with at least 1 HLA-DRB1*1501 allele had a later age at menarche than did participants with no risk alleles (MS: mean difference = 0.49, 95% confidence interval [CI] = [0.03-0.95], p = 0.036; GEMS: mean difference = 0.159, 95% CI = [0.012-0.305], p = 0.034). This association remained after we adjusted for body mass index at age 18 (available in GEMS) and for other MS risk alleles, as well as a single nucleotide polymorphism near the HLA-A region previously associated with age of menarche (available in MS cohort). Confirming previously reported associations, in our MS cohort, every year decrease in age at menarche was associated with a 0.65-year earlier MS onset (95% CI = [0.07-1.22], p = 0.027, N = 540). Earlier MS onset was also found in individuals with at least 1 HLA-DRB1*1501 risk allele (mean difference = -3.40 years, 95% CI = [-6.42 to -0.37], p = 0.028, N = 156).

CONCLUSIONS

In 2 cohorts, a genetic marker for earlier MS onset (HLA-DRB1*1501) was inversely related to earlier menarche, an experiential marker for earlier symptom onset. This finding warrants broader investigations into the association between the HLA region and hormonal regulation in determining the onset of autoimmune disease.

Factors associated with onset, relapses or progression in multiple sclerosis: A systematic review

Multiple sclerosis (MS) is a chronic disease of the central nervous system with an unidentified etiology. We systematically reviewed the literature on the possible risk factors associated with MS disease onset, relapses and progression from 1960 to 2012 by accessing six databases and including relevant systematic reviews, meta-analyses, case-control or cohort studies. The focus was on identifying modifiable risk factors. Fifteen systematic reviews and 169 original articles were quality assessed and integrated into a descriptive review. Best evidence, which included one or more prospective studies, suggested that lower exposure to sunlight and/or lower serum vitamin D levels were associated with an increased risk of developing MS onset and subsequent relapses, but a similar quality of evidence was lacking for disease progression. Prospective studies indicated that cigarette smoking may increase the risk of MS as well as accelerate disease progression, but whether smoking altered the risk of a relapse was largely unknown. Infections were implicated in both risk of developing MS and relapses, but data for progression were lacking. Specifically, exposure to the Epstein-Barr virus, particularly if this manifested as infectious mononucleosis during adolescence, was associated with increased MS risk. Upper respiratory tract infections were most commonly associated with an increase in relapses. Relapse rates typically dropped during pregnancy, but there was no strong evidence to suggest that pregnancy itself altered the risk of MS or affected long-term progression. Emerging research with the greatest potential to impact public health was the suggestion that obesity during adolescence may increase the risk of MS; if confirmed, this would be of major significance.

Assessing the Risk Factors for Multiple Sclerosis in Women of Reproductive Age Suffering the Disease in Isfahan Province

BACKGROUND

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system. Etiology of the disease is not well understood; however, it is more common in women than in men and occurs mainly during reproductive age. The aim of this study was to evaluate some risk factors in women of childbearing age with MS in Isfahan Province.

METHODS

This analytic case-control study was conducted in MS Clinic in Isfahan, 2014. The study was done on 200 patients with MS and 200 nonpatients (matched controls) that were randomly selected for inclusion in the study. The data collection tool was a researcher-designed questionnaire consisting of three parts: Demographics, disease characteristics, and some risk factors related to reproductive age. Data were analyzed by SPSS version 20, using descriptive and inferential statistics.

RESULTS

The results showed that risk of MS had a significant relationship with age at menarche (P < 0.001), prior use of oral contraceptives (OCs) (P = 0.002), duration of use of OCs (P = 0.008), and number of pregnancies (P < 0.001). However, there was no significant relationship between age of onset of use of OCs (P = 0.80) and age at the first pregnancy (P = 0.45) with the risk of MS.

CONCLUSIONS

Results of this research determined that the following risk factors were associated with developing MS, age at menarche, history, and duration of use of OCs and number of pregnancies.

Menarche increases relapse risk in pediatric multiple sclerosis

BACKGROUND

Multiple sclerosis (MS) predominantly affects women with a sex ratio of 3:1 in contrast with a 1:1 sex ratio seen in pre-pubertal onset. Thus, puberty may influence MS risk differentially in males and females. How puberty may be associated with MS clinical features and disease course remains unknown.

OBJECTIVE

The objective of this paper is to determine the association of menarche with disease course in girls with MS.

METHODS

This is a longitudinal retrospective study from the UCSF Regional Pediatric MS Center database. We categorized patients by time of disease onset: pre-menarche, peri-menarche and post-menarche. Poisson regression models were used for within-subject relapse analyses offset by follow-up time.

RESULTS

Seventy-six girls were included (pre-menarche onset = 17; peri-menarche onset = 9; post-menarche onset = 50). Age of menarche was similar in all groups (Kruskal-Wallis p = 0.19). Relapse rate was the same in all three groups during the first two years of follow-up. In girls with follow-up overlapping at least two time periods, within-subject analyses showed increased relapses during the peri-menarche compared to post-menarche period (adjusted IRR = 8.5, 95% CI 2.5-28.7, p = 0.001).

CONCLUSION

Pubertal status may influence MS course at least in female patients. Understanding how puberty influences MS clinical features may offer new insights into important factors regulating disease processes.

Sex-Based Differences in Multiple Sclerosis (Part I): Biology of Disease Incidence

Multiple sclerosis (MS) is a chronic autoimmune demyelinating disease that leads to neuron damage and progressive disability. One major feature of multiple sclerosis (MS) is that it affects women three times more often than men. In this chapter, we overview the evidence that the autoimmune component of MS, which predominates in the early stages of this disease, is more robust in women than in men and undergoes a sharp increase with the onset of puberty. In addition, we discuss the common rodent models of MS that have been used to study the sex-based differences in the development of central nervous system (CNS) autoimmunity. We then address the biological underpinnings of this enhanced MS risk in women by first reviewing the autoimmune mechanisms that are thought to lead to the initiation of this disease and then honing in on how these mechanisms differ between the sexes. Finally, we review what is known about the hormonal and genetic basis of these sex differences in CNS autoimmunity.

Puberty in females enhances the risk of an outcome of multiple sclerosis in children and the development of central nervous system autoimmunity in mice

BACKGROUND

For reasons that remain unclear, three times more women develop multiple sclerosis (MS) than men. This preponderance among women is evident only after 12 years of age, implicating pubertal factors in the risk of MS.

OBJECTIVE

To investigate the influence of female puberty on central nervous system (CNS) autoimmunity.

METHODS

We examined the relationship between age of menarche on MS outcomes in 116 female children (< 16 years old) whom presented with incident 'acquired demyelinating syndromes' (ADS) and were followed prospectively in the national Canadian Pediatric Demyelinating Disease Study, from 2004-2013. Furthermore, we directly investigated the effects of puberty on susceptibility to experimental autoimmune encephalomyelitis (EAE) in two groups of female mice that differed only in their pubertal status.

RESULTS

In the ADS children, a later age of menarche was associated with a decreased risk of subsequent MS diagnosis. This relationship persisted, after accounting for patient age at ADS presentation and the presence of ≥1 T2 lesions on brain magnetic resonance imaging (MRI), with a hazard ratio (HR) of 0.64; and additional factors that associate with MS outcomes in ADS children, including low vitamin D levels. Furthermore, we found female mice that had transitioned through puberty were more susceptible to EAE than age-matched, pre-pubertal mice.

CONCLUSION

Puberty in females enhances CNS autoimmune mechanisms that lead to MS in humans and EAE in mice.

Higher weight in adolescence and young adulthood is associated with an earlier age at multiple sclerosis onset

BACKGROUND

Growing evidence suggests an association between adolescent obesity and increased risk of multiple sclerosis (MS).

OBJECTIVE

The objective of this paper is to investigate whether weight or body mass index (BMI) in adolescence and young adulthood was associated with age at MS symptom onset.

METHODS

Our cohort is comprised of a sub-group of 184 women enrolled in the New York State MS Consortium registry. Individuals were asked to recall their weight at the time of first menstruation and at age 25. BMI was calculated accordingly for age 25. Regression analyses were carried out to investigate the association between weight or BMI and age at onset.

RESULTS

Weight at menarche was significantly related to younger age at symptom onset (β = -0.073, p = 0.001). These results were also found at age 25 for weight (β = -0.080, p < 0.001) and BMI (β = -0.448, p = 0.001). Significantly earlier disease onset (26.9 years ±9.9) was observed in individuals who were overweight at 25 compared to those who were not overweight (32.1 years ±9.2, p = 0.006).

CONCLUSIONS

Women who reported higher weight in adolescence and BMI in early adulthood were younger at MS onset. Future research should investigate whether there is a causal link between body weight and MS, as prevention lifestyle and dietary interventions could be implemented.

Female gender and reproductive factors affecting risk, relapses and progression in multiple sclerosis

Multiple sclerosis (MS), a chronic inflammatory demyelina-ting and degenerative disease of the central nervous system, is a frequent cause of neurological disability in young adults. Female predominance has increased over the last decades. Although female gender carries a higher risk of developing relapsing remitting MS, being female and at child-bearing age also appears to provide some protection against cognitive decline and against progressive onset MS, an adverse predictive factor when considering long-term disability in MS. The risk of MS in women has been associated with an earlier age at menarche. In most studies, parity did not impact MS risk. However, the recently published association of higher parity and offspring number with a reduced risk of a first demyelinating event suggests a potential suppressive effect. Pregnancy in MS patients has been associated with a reduced relapse rate and a reduction of neurological symptoms, especially in the third trimester. Despite the increased relapse risk in the postpartum period, there is no indication of an adverse effect of childbirth on the long-term course of MS. Fertility treatment in MS has been associated with an increased relapse risk in the following 3-month period, especially when the procedure did not result in pregnancy and gonadotrophin-releasing hormone agonists were used. Altogether, there is substantial evidence to support a regulatory role of sex steroid hormones in MS. In the absence of correlations with single hormone blood levels, we can only speculate about the underlying mechanisms. In conclusion, the increased MS risk in women and the changes in relapse and progression risk in association with reproductive events suggest significant and complex interactions between immune, neuroendocrine and reproductive systems in MS.

Female reproductive issues in multiple sclerosis

Multiple sclerosis (MS) is more common in females than males and frequently affects women during their reproductive years. Thus, issues surrounding pregnancy and reproduction are of concern to women with MS. This review documents studies that shed light on reproductive issues in women with MS. The available literature was searched for papers relating to pregnancy and MS. Pregnancy is protective in MS in the short term, perhaps due to modulation of the immune system in pregnancy. It also possible that changes in the brain in pregnancy could protect against the effects of inflammation. The long-term effects of pregnancy also seem to be beneficial to MS, perhaps due to long-term epigenetic changes or possibly due to the effects of fetal microchimerism. Obstetric outcomes in women with MS are similar to those in the general population. In addition, there have been no reports of severe fetal abnormalities in babies exposed to first-line MS therapies. There is no good evidence that breast-feeding is protective in MS. There is no evidence that oral contraceptive pill use predisposes to MS, nor influences the clinical course of MS. After menopause, there is possible deterioration of MS, but it’s difficult to disentangle this from the effects of aging and the natural progressive history of MS. The strong biological effect of pregnancy on MS deserves further study, so that these mechanisms can possibly be replicated as therapies for MS.

Menarche, oral contraceptives, pregnancy and progression of disability in relapsing onset and progressive onset multiple sclerosis

Female gender and hormones have been associated with disease activity in multiple sclerosis (MS). We investigated age at menarche, use of oral contraceptives and pregnancy in relation to progression of disability in relapsing onset and progressive onset MS. We conducted a cross-sectional survey among individuals with MS, registered by the Flemish MS Society in Belgium. A time-to-event analysis and Cox proportional hazard regression were performed with time to Expanded Disability Status Score (EDSS) of 6 (requires a cane) as outcome measure. Hazard ratios for the time from onset and the time from birth were adjusted for age at onset and immunomodulatory treatment. Data on 973 women with definite MS were collected. In the relapsing onset group, women with at least two pregnancies had a reduced risk to reach EDSS 6 compared with nulliparous women. In the progressive onset group, later age at menarche was associated with a reduced risk to reach EDSS 6, whereas oral contraceptive use was associated with a higher risk of reaching EDSS 6. Our study corroborates the association of pregnancies with a reduced progression of disability in relapsing onset MS. In progressive onset MS, a slower progression was found in women with a later onset of menarche and a more rapid progression occurred when women reported the use of oral contraceptives.

Gender issues in multiple sclerosis: an update

Although multiple sclerosis (MS) affects both women and men, women are more susceptible to MS than men. Accumulating evidence indicates that the incidence and prevalence of MS is increasing, more so in women than in men. Owing to pregnancy, differing hormonal states and distinct social roles, the impact of MS differs between women and men. Since Patricia K Coyle published a review on gender issues in MS, multiple studies have added to the body of knowledge. This update will summarize the current thinking on gender-related issues in MS and we will address incidence and prevalence, hormonal factors, pregnancy and breastfeeding, genetics, course and prognosis, imaging, treatment and psychosocial aspects. Future progression within this field will help elucidate the cause of and define the treatment of MS.

Influence of neurosteroids on the pathogenesis of multiple sclerosis

This paper summarizes neuroendocrine effects on myelination and their possible relevance for the pathogenesis of multiple sclerosis (MS). Steroid hormones known as neurosteroids are synthesized in the human central nervous system (CNS) and exert local effects on glial and neuronal tissue. Progesterone derivatives seem to act as promyelinating factors in the slow but continuous process of myelin maintenance in the adult human brain. Diminished production of these myelin-promoting factors may lead to the formation of structurally altered and less stable myelin, resulting in the observed pathology of the normal-appearing white matter (NAWM) in MS. Dysmyelination, characterized by an altered myelin protein composition, reduced myelin content and increased vulnerability of the myelin sheath, precedes the formation of inflammatory lesions and the clinical onset of disease. Defects in the myelin sheath first occur in mechanically strained areas of the brain, where myelin turnover is physiologically increased. The continuous exposure of myelin proteins, normally sheltered from immunosurveillance, will lead to microglia activation and phagocytosis of myelin. Phagocytic cells from the brain and myelin material may drain to cervical lymph nodes with subsequent priming of T-cells. Finally, heterogenous focal auto-inflammatory reactions contribute to the clinical symptoms of the disease. Neurosteroids influence the biochemical composition of myelin proteins and promote myelin renewal. These promyelinating neurosteroidal functions seem to be impaired in the MS brain. Contrary to the view of auto-inflammatory demyelination being a causative factor in MS pathogenesis, it is argued here that widespread dysmyelination in the adult human brain precedes and induces a focal immune response to various myelin compounds.