Influence of mountain climate on multiple sclerosis

Abstract

Objective: Multiple sclerosis (MS) is a chronic autoimmune disease that affects the central nervous system. Although the exact cause of multiple sclerosis is unknown, it is believed to be a combination of genetic and environmental factors. One of the environmental factors is climate, including the influence of the mountain climate on this disease. We aimed to analyze current evidence on influence of mountain climate on multiple sclerosis. Methods: We followed the guidelines for the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement. Reviewers systematically searched Scopus, PubMed and EMBASE for peer-reviewed publications in English from January 1994 to December 2022 reporting MS and influence of mountain climate. The outcome was change in MS incidence rate according to geographical region. Results: The mountainous climate is characterized by high-altitude, low humidity and extreme temperatures, which can have both positive and negative effects on multiple sclerosis. On the one hand, a cold and dry mountain climate can be beneficial for people with multiple sclerosis, as it can reduce inflammation and improve symptoms such as fatigue, cognitive impairment, and spasticity. In addition, high altitude may have a protective effect on multiple sclerosis, as it is associated with a lower incidence rate. On the other hand, mountain climates can also have a negative impact on multiple sclerosis, especially in terms of vitamin D deficiency. Sun exposure is the main source of vitamin D, and people living at higher altitudes get less sunlight due to the thinner atmosphere, resulting in the body producing less vitamin D. Conclusion: Thus, the influence of mountain climate on multiple sclerosis is complex and depends on many factors. Further research is needed to better understand the relationship between altitude and MS risk.