This isn't a large enough group to study, but that age group is the people doing IVF these days. This study also ignores genetic heart problems. My father doesn't fit the age group, but he has sarcadosis. Reads like it's trying to make IVF money.

On the other hand, men who became fathers earlier in life -- age 25 or younger -- tended to have worse heart health and higher death rates.

“If you’re under 25, you may be less financially stable, your brain may be less mature and, especially for racial and ethnic minorities, you may have lower-paying jobs with fewer benefits and limited leave policies,” Parker said. “All of this can make it harder to focus on your health. There are a lot of public health interventions for young mothers, but no one has ever really looked at young fathers in this way.”