Parental ethnicity associated with risk for multiple sclerosis: A population-based incident case–control study in Iran

Multiple sclerosis projection in Tehran, Iran using Bayesian structural time series

BACKGROUND

The prevalence of Multiple Sclerosis (MS) has been increasing worldwide and the highest prevalence ratio among Asian countries was reported in Iran. This study aims to estimate the increase in MS occurrence during more than three decades in Tehran and forecast the future condition of the disease using time series approaches for the next ten years.

METHODS

The cross-sectional study was conducted from 1999 to 2019 based on records of MS cases from Iranian MS Society (IMSS) registry system. The prevalence was estimated using population data presented by the Statistical Centre of Iran. Through Bayesian Structural Time Series (BSTS) model, we want to predict the prevalence of familial and sporadic MS in the next ten years. .

RESULTS

Among 22,421 cases with MS, 16,831 (75.1 %) were female and 5589 (24.9 %) were male. Female to male ratio was 3.0:1 and the number of familial MS cases were 2982 (13.3 %) of subjects. Female gender was less responsible for higher rate of MS in familial definition (beta = 0.020) in comparison to sporadic cases (beta = 0.034). Forecasting by BSTS revealed an increase in MS prevalence for the next ten years so that the prevalence rate for total, familial and sporadic MS respectively begins with 189.50 (183.94-195.14), 25.69 (24.97-26.45) and 163.74(159.06-168.57) in 2020 and ends with 220.84 (171.48-266.92), 30.79 (24.16-37.15), and 189.33(146.97-230.19) in 2029.

CONCLUSIONS

According to the findings, MS prevalence increased during three decades and it will increase over the next ten years. Tehran province is one of the regions with highest MS prevalence in Asia. The results of present study indicated that females are at higher risk for MS than males in both sporadic and familial MS.

Prenatal and perinatal factors associated with developing multiple sclerosis later in life: A systematic review and meta-analysis

OBJECTIVE

Both genetic and environmental factors play roles in Multiple Sclerosis (MS) etiopathogenesis. The relationship between prenatal/perinatal factors/exposures and future MS occurrence in the offspring remains controversial. Here, we aimed to review the available evidence on prenatal/perinatal factors associated with later MS occurrence.

METHOD

We performed systematic search of PubMed, Web of Science, and Scopus from inception to October 2020. We included original observational studies conducted on human participants addressing the association between prenatal/perinatal factors and MS occurrence. Data were extracted according to the PRISMA guideline. The adjusted odds ratio (OR) with 95% confidence interval (CI) was considered as the desired effect size. The heterogeneity was evaluated by Cochran's Q and I² and the publication bias was assessed. We excluded gestational/neonatal vitamin D level, season of birth, and latitude because of recently published systematic reviews/meta-analyses on these subjects.

RESULTS

Overall, 2306 records were identified in the primary search. After excluding irrelevant studies, we evaluated 34 studies with contributing data on 100 prenatal/perinatal factors associated with an increased or decreased risk of MS occurrence. In the meta-analyses, we found no statistically significant associations between later MS occurrence in offspring and prenatal smoking exposure (OR = 1.01, 95% CI = 0.77-1.34), mode of delivery (OR = 0.90, 95% CI = 0.52-1.56), birth order (OR = 0.85, 95% CI = 0.72-1.00), and maternal age (OR = 1.34, 95% CI = 0.88-2.04). Paternal age and parents' marital status at the time of childbirth, maternal preeclampsia/ toxemia, forceps use, birth weight, plurality, and preterm birth were the other most studied factors, and none reported to affect MS risk.

CONCLUSION

We found that prenatal smoking exposure, mode of delivery, birth order, and maternal age do not affect risk of future MS development. Moreover, most of the other investigated factors were reported not to affect MS risk in the offspring.

Stressful life events and the risk of primary progressive multiple sclerosis: A population-based case-control study

BACKGROUND

The onset and presentation of primary progressive multiple sclerosis (PPMS) like any other autoimmune diseases can be triggered by unexpected lifetime stressful events, which require to be assessed in order to minimize our exposure to such events as much as possible.

OBJECTIVE

The aim of the present study was to determine the possible role of socioeconomic status (SES) and stressful events in PPMS development METHODS: The present population-based case-control study recruited PPMS cases and healthy controls from the general population during 2019-2020 in Tehran, Iran. Clinical diagnosis of cases was based on the 2017 McDonald criteria and confirmed by a neurologist. The selection of sex-matched controls from the same source population of cases was performed using the standard method of Random Digit Dialing (RDD). The study questionnaire was filled out over telephone interviews. Matched logistic regression was administered to estimate the adjusted and unadjusted odds ratio (OR) at 95% confidence intervals (CIs) adjusted for sex, age, and marital status using SPSS 23.

RESULTS

This study examined 146 PPMS cases and 294 controls. Mean ages (SD) for cases and controls were 46.97 (9.4) and 37.67 (6.12), respectively (P < 0.001). No stressful events over five years prior to the disease onset were associated with an increased risk of PPMS. Marriage (OR: 0.04; 95% CI (0.01- 0.37), P = 0.004), close family members' serious disease (OR: 0.10; 95% CI (0.02-0.60), P = 0.01), and being in debt (OR: 0.03; 95% CI (0-0.37), P = 0.006) were found to have a negative association with the risk of disease occurrence. Death of a loved one, family disruption, jail term, homelessness period, Conquer(national university entrance exam), death of spouse, getting fired from a job, joblessness, divorce, migration, close family members' suicide, and retirement were not associated with the risk of PPMS (P > 0.05). History of depression before the PPMS presentation was considerably associated with the incidence of PPMS (P < 0.001). Self-rated health status was scored noticeably lower by cases as compared with controls (P < 0.001). Participants with the paternal educational degree of guidance school showed a higher risk of PPMS by 2.83 time (OR: 2.83; 95% CI (1.02 - 7.80), P = 0.04) than participants with university educated fathers. In total, SES during adolescence did not indicate any association with the risk of PPMS (with the exception of levels 2 (P = 0.02) and 7 (P = 0.05)).

CONCLUSION

No stressful life events were identified as possible increasing risk factors for PPMS. Marriage, close family members' serious disease, and being in debt had a negative association with the disease risk. The history of depression may elevate the risk of PPMS. While the highest and lowest SES levels in adolescence were not remarkable determiners for PPMS, levels 2 and 7 had a positive association with the risk of PPMS. The maternal educational level was not an important factor; however, the paternal educational degree of guidance school as compared to university degree made individuals more susceptible to PPMS. Self-rated health status score was higher in controls.

Prevalence and incidence of multiple sclerosis in Ardabil, Northwest of Iran

BACKGROUND

Multiple sclerosis (MS) epidemiology is studies in many populations; however, studying populations with unique characteristics could provide opportunities to deepen the understanding of the underlying reason of the disease. In this regard, we aimed to study the epidemiology of MS in Ardabil, a province in northwest Iran, where the majority are of Iranian Azerbaijanis.

METHOD

A retrospective population-based study was conducted from 2008 to 2018 in Ardabil, based on the data of Iran's Ministry Of Health. Collected information includes sex, age, age at disease onset, education and type of MS. We used t-test to compare means and chi-square test to analyze the association among variables.

RESULTS

The total number of patients was 760 with 533 (70.13%) females and 227 (29.87%) males. The crude prevalence was 59.37 per 100,000 in 2018 (95% CI: 55.31, 63.73). The crude incidence rate was 7.65 per 100,000 in 2018 (95% CI: 6.28, 9.32). The most frequent educational level was high school diploma (38.36%). The relapsing-remitting (RR) form was the most frequent type of MS (48.16%). The F/M ratio was 2.92:1 and the mean onset age was 33.14 (95% CI: 31.56, 34.72) in 2018, significantly higher in males (P value= 0.01).

CONCLUSION

Ardabil is a medium risk zone of MS. The different ethnicity of its population, climate and environmental features, may explain the factors modulating the risk of MS in similar areas and present windows of opportunity to understand the causes of MS.

Association of Interleukin-1 and Inteleukin-1 Receptor Antagonist Gene Polymorphisms with Multiple Sclerosis in Azeri Population of Iran

BACKGROUND

Cytokines as important mediators have a critical role in appropriate immune responses, the irregular production of which can lead to Multiple Sclerosis (MS). Proinflammatory cytokine interleukin-1 (IL-1) triggers inflammatory responses. Function and production of the cytokine are influenced by IL-1 coding gene polymorphism and those antagonists gene polymorphism.

OBJECTIVE

The aim of the present study was to evaluate the possible correlation between MS and IL-1 related alleles in Azeri population of Iran.

METHODS

Variable number tandem repeats (VNTR) genotypes of 150 MS patients and 220 healthy non-relative controls were determined.

RESULTS

In the healthy controls, genotype TT at IL-1A (-889) location was significantly higher than the MS patients (p=0.0001). However, a significant difference was not found between the two groups in genotypic/allelic frequency at IL- 1B+ 3953 location. Evaluation of the IL-1RA gene revealed that genotype 1/2, and genotype 1/3 were significantly higher in the healthy controls and MS patients, respectively. Our findings indicated that the consumption of fast-food in MS patients was significantly higher than controls (p= <0.05). Also, a considerable number of MS patients had inappropriate dieting behaviors such as not eating breakfast (p= 0.0001), and irregular eating habits (p= 0.0001).

CONCLUSION

Polymorphisms of the IL-1B genes and common alleles of IL-1RA were not considered as risk factors for MS disease. However, genotype TT at IL-1A (-889) location and the rare allele of IL-1RA3 can be a potential risk factor for the disease. Furthermore, inappropriate dieting behaviors and consumption of fast-food can increase the risk of MS.

The changing course of multiple sclerosis: rising incidence, change in geographic distribution, disease course, and prognosis

PURPOSE OF REVIEW

This review provides a brief update of new research findings on the changing epidemiology, disease course, and prognosis of multiple sclerosis (MS).

RECENT FINDINGS

Evidence not only continues to support the female predominance in incidence and prevalence of the disease but also supports an increase in incidence of MS in geographic areas that were previously considered to be low incidence for the disease.

SUMMARY

An increased interest in population-based registries and databases will provide more valid epidemiological measures and observational studies conducted in well-defined study populations. Such studies are crucial for an accurate description of both changing prognosis of MS and differential characteristics of the various MS phenotypes.