Stroke in the young (< 45 years old) is rare, yet may be increasing in prevalence due to the rise in traditional risk factors such as hypertension and obesity. Whether altitude is a risk factor for stroke in the young has not been examined. At our high elevation state (Colorado), a high proportion of strokes occur in young persons.

We conducted an ecologic study utilizing the most recent U.S. census data (2010) and data from the Healthcare Cost and Utilization Project (HCUPnet- 2015), provided by the Agency for Healthcare Research and Quality. HCUPNet data were used to calculate what proportion (%) of stroke admissions were in young persons, by state. Census data were used to calculate prevalence rates (per 100,000 young persons) of stroke in the young, by state. Proportions and prevalence rates were each examined against the average state elevation and analyzed with a generalized linear regression model. Results are presented from highest state elevation to lowest state elevation as follows: 6-7000ft, 5-6,000ft, 3-5,000ft, 2-3,000ft, 1-2,000ft, and < 1,000 ft.

High altitude states had the highest proportion of stroke admissions in young persons, which decreased with decreasing elevation (r-square=0.18, p=0.02). The proportion of young strokes from high to low elevations were: 4.6%, 4.1%, 3.3%, 3.2%, 3.5%, and 3.4%. On the contrary, high altitude states had the lowest prevalence rate of young strokes per 100,000 young persons. Prevalence rates increased with decreasing altitude: 7.1, 9.3, 9.4, 9.1, 10.4, 12.0 (r-square=0.18, p=0.02).