Body Fat Is Associated With Reduced Aortic Stiffness Until Middle Age

I'm sure there is a correlation between stiff arteries and stroke, but I don't know about it. You can test if you have stiff arteries here and here.
You can fix them via this. Don't listen to me I have no medical training. Your doctor can tell you if fixing your stiff arteries would lead to dangerously low blood pressure and the risk of stroke from that.

Stiff arteries relax like younger blood vessels after taking alagebrium

I'm probably carrying an extra 20 pounds and I am middle-aged. So I should do something about that. Exercise, exercise, exercise.
http://hyper.ahajournals.org/content/early/2013/04/22/HYPERTENSIONAHA.113.01177.reprint

Abstract

Obesity is a major risk factor for cardiometabolic disease, but the effect of body composition on vascular aging and arterial stiffness remains uncertain. We investigated relationships among body composition, blood pressure, age, and aortic pulse wave velocity in healthy individuals. Pulse wave velocity in the thoracic aorta, an indicator of central arterial stiffness, was measured in 221 volunteers (range, 18–72 years; mean, 40.3±13 years) who had no history of cardiovascular disease using cardiovascular MRI. In univariate analyses, age (r=0.78; P < 0.001) and blood pressure (r=0.41; P< 0.001) showed a strong positive association with pulse wave velocity. In multivariate analysis, after adjustment for age, sex, and mean arterial blood pressure, elevated body fat% was associated with reduced aortic stiffness until the age of 50 years, thereafter adiposity had an increasingly positive association with aortic stiffness (β=0.16; P < 0.001). Body fat% was positively associated with cardiac output when age, sex, height, and absolute lean mass were adjusted for (β=0.23; P=0.002). These findings suggest that the cardiovascular system of young adults may be capable of adapting to the state of obesity and that an adverse association between body fat and aortic stiffness is only apparent in later life.

More explanation about this here: From Imperial College, London.
Body fat hardens arteries after middle age