Higher body mass index at ages 16 to 20 years is associated with increased risk of a multiple sclerosis diagnosis in subsequent adulthood among men

Background: Evidence for the association between body mass index (BMI) and multiple sclerosis (MS) among men remains mixed. Objective and methods: Swedish military conscription and other registers identified MS after age of 20 years and BMI at ages 16-20 years (N = 744,548). Results: Each unit (kg/m(2)) BMI increase was associated with greater MS risk (hazard ratio and 95% confidence interval = 1.034, 1.016-1.053), independent of physical fitness (1.021, 1.001-1.042). Categorised, overweight and obesity were associated with statistically significant raised MS risk compared to normal weight, but not after adjustment for physical fitness. Conclusion: MS risk rises with increasing BMI, across the entire BMI range.

Automated summary

This study found that for men, each unit increase in BMI is associated with a higher risk of multiple sclerosis. Overweight and obesity are linked to a significantly increased risk of MS compared to normal weight individuals, but this association is no longer significant after adjusting for physical fitness.