Incidence rate and sex ratio in multiple sclerosis in Lithuania

Abstract

ObjectivesTo determine the temporal changes in incidence rates of multiple sclerosis (MS) over the past 15 years in Lithuania with prediction up to 2020, and to estimate female‐to‐male sex ratio and its changes among MS patients.Materials and MethodsWe conducted a descriptive incidence study. The crude incidence rates (CIR) were calculated using 15‐year period, sex, age‐groups, and the number of newly registered MS patients. Standardized incidence rates (SIR) were calculated using European standard in order to evaluate the influence of resident structure changes on incidence of MS during the last 15 years. The data were processed using Minitab set to estimate a linear trend model for the temporal changes of 16 parameters.ResultsThe data showed a substantial growth of the incidence rate of MS in Lithuania during the period of 2001–2015. In 2001, MS was diagnosed to 162 new individuals, whereas 343 new cases of MS were diagnosed in 2015. During 2001–2015, the incidence of MS was on average 6.5 (95% CI 5.70–7.30) cases per 100,000 residents, and 4.9 (95% CI 4.46–5.34) and 8.1 (5.86–9.34) for 100,000 male and female, respectively. Female‐to‐male sex ratio in MS in Lithuania had a tendency to increase over the period. Females were affected from 1.5 to 2 times more often than males.ConclusionsIn 2020, the incidence rate of MS is estimated to reach 13 cases per 100,000 persons and females are expected to be diagnosed with MS two times more often than males.

Age-period-cohort analysis of the incidence of multiple sclerosis over twenty years in Lorraine, France

“…Overall the sex ratio was stable over the period, in contrast to other studies finding a marked increase in the female-to-male sex ratio of MS incidence in many countries over the past 50 years 4 , 27 , 28 . In Argentina, Rojas et al found a variation of 1.8–2.7 over 50 years 4 , In Lithuania, Valadkeviciene et al found a variation of 1.5–2 29 . This change in the female-to-male ratio is generally driven by an increasing MS incidence in women rather than a decline in that of men.…”

Prevalence and Incidence of Multiple Sclerosis in Russian Federation: 30 Years of Studies

“…The observed rise in F/M ratio cannot be easily explained by genetics or by new diagnostic technologies or increased awareness, which would apply to both sexes. Results of numerous population-based studies in different parts of the world and the meta-analyses suggest that the recent increase of MS incidence provide some evidence that this has primarily resulted from an increase in the incidence of MS among women [77][78][79][80][81][82];…”

Cytokine Profile in Patients with Multiple Sclerosis Following Exercise: A Systematic Review of Randomized Clinical Trials

“…Multiple sclerosis (MS) is defined as an immune-mediated inflammatory, neurodegenerative, and demyelinating disease that impacts the central nervous system (CNS) in young individuals [1,2]. Approximately 1 to 2.5 million people (mostly women, with a female-to-male ratio of 2:1) around the world are affected by MS [3]. A variety of genetic and environmental factors, including immune system dysregulation, central nerve demyelination [4,5], vitamin D deficiency, Epstein-Barr virus, and smoking [6], have been considered as possible etiologies of MS.…”