Super-busy superstars Rihanna, J.Lo, and Mariah Carey have all admitted to being so wound up by their nonstop schedules and ambitions that they got very little sleep for years. They say they've changed their ways now. I hope so.

A new study shows that insomnia and sleep deprivation (getting five or fewer hours of sleep nightly) increase the risk of having a heart attack by 69%.

What's the cause? Lab studies show that chronic stress and increased levels of the stress hormone cortisol speed up damage to blood vessels, increasing the risk of heart attack.

When a person has diabetes and insomnia, the risk is even greater — and it's estimated that 50% of people with diabetes contend with insomnia and other sleep issues, fueled by fluctuations in blood glucose levels.

If you're concerned about your heart health — and you should be, as 77.5% of men and 75.4% of women ages 60 to 79 have some form of cardiovascular disease, according to the American Heart Association — improving your sleep habits should be right up there with managing stress, eating a plant-based diet, and getting 300 minutes of physical activity a week.

For chronic insomnia, step number one is to see a sleep specialist who can explore your habits and uncover the causes of your sleep problems.

And make sure to practice stress management, maintain a regular bed time in a dark, cool room with no digital devices, and eat a lighter meal for dinner, no later than 7 p.m.