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Multiple Sclerosis => MS - RESEARCH AND NEWS => Topic started by: agate on September 18, 2016, 09:56:46 am

Title: (ECTRIMS) Early menarche linked to increased MS risk and earlier age at MS onset...
Post by: agate on September 18, 2016, 09:56:46 am
Presented as poster session #326 at the annual ECTRIMS conference (London, September 14-17, 2016):

Quote
- Early menarche is associated with increased risk of multiple sclerosis and earlier age at onset of multiple sclerosis in Danish patients

A.B. Oturai1, J.H. Laursen2, N. Koch-Henriksen3, F. Sellebjerg2, L.W. Thørner4, H. Ullum4, H.B. Søndergaard2

1Department of Neurology, 2Neurology, Danish Multiple Sclerosis Center, Department of Neurology, Copenhagen University, Rigshospitalet, 3Danish Multiple Sclerosis Registry, Copenhagen University, Rigshospitalet, 4Department of Clinical Immunology, Rigshospitalet, Copenhagen, Denmark

Background:

Time of menarche has declined over the last century. It has been suggested that this may contribute to the increasing incidence of multiple sclerosis (MS) among women. Previous studies have shown conflicting results regarding the influence on age at MS onset.

Objectives:


To study time of menarche and risk of MS in a case-control design in ethnic Danish individuals, and further to evaluate the influence on time at MS onset.

Methods:

Data from a comprehensive environmental/lifestyle questionnaire were collected from Danish MS patients and controls. MS patients were recruited among 2775 individuals from the Danish MS Biobank, 2058 (74%) responded. The control group consisted of blood donors, recruited from five major donor locations, where only two places were able to calculate the response rate which was 75 and 90%. In total we have questionnaire data from 7289 individuals (2058 cases and 5231 controls). Of these, 529 (7%) were excluded due to other etnicity than Danish and other 248 (3%) for age corrections. Thus, we included 6512 individuals (1827 patients and 4685 controls). 3408 (96%) women (1295 patients, 2113 controls) had completed data sets for the investigated parameters and were included in the analyses. Information on age at onset was obtained from the Danish MS Registry. A logistic regression model was used to investigate the association between menarche and the risk of MS. The risk was adjusted for year of birth. Univariate regression analysis was used to evaluate the association between time of menarche and age at disease onset.

Results:

 Mean (SD) age at menarche was lower in patients compared to controls, 13.1 (1.5) vs 13.3 (1.4), p=0.01. For each additional year of menarche the risk of MS decreased by 5% (Odds ratio = 0.95 (95% confidence interval (CI) 0.905-0.997, p < 0.04)). Additionally, we found a positive association between age at menarche and age at MS onset (p < 0.001), with an effect size of 0.67, meaning that age at onset decreases 0.67 years as age of menarche decreases by one year.

Conclusions:

 We found an association between earlier age at menarche and increased risk of MS. In addition, we found an association between earlier age at menarche and earlier age at onset of MS.