BMI isn't exactly comparable between the sexes, since males and females have different distributions of adipose and visceral fat, and the impacts of these are clearly different.
And that could maybe contribute to something. There were other studies, though, which didn't take BMI into account at all, even though high BMI is a known risk factor, and generally more men are obese than women.
I saw this study from southern California. They provide risk ratios for different factors. Seems just being male have a higher risk ratio than being overweight.
Those kinds of effects would presumably count as "gender-specific differences". Previous investigations never really took body mass into account at all, which was...bad.