A recent study says less than six hours of sleep per night can lead to cancer or early death for someone middle aged or older with existing high blood pressure, type 2 diabetes or heart disease.
Any of those conditions are already risk factors for heart attacks or strokes. Dr. Sreenivas Gudimetla, a cardiologist with Texas Health Fort Worth, explains why too little sleep can make matters worse.
Why too little sleep is dangerous for people at risk for heart attacks and strokes: “First of all, we know that the autonomic nervous system, sort of your fight or flight response, actually is higher in sleep deprived patients. Anytime you have adrenaline activity that increases your heart rate, it increases your blood pressure. It also increases the workload of the heart. And along with that ... when you increase blood pressure, you increase the risk of cardiovascular event.”
Other things that can go wrong when you get too little sleep: "The other thing that could happen is you can actually have increased blood sugars with sleep deprivation. You get an impairment in the metabolism of glucose, for instance. It is also believed that at the level of the blood vessel wall, you can have higher inflammation, which causes increased plaque buildup, which results in an increased risk of cardiovascular events."
How sleep helps the body: “First of all, it improves brain health to be much more sharper in your thinking. It improves your energy levels. One of the things that is true is that when people sleep, their heart rates are much lower. So the heart actually is rested.”
How this study differs from others: "Patients actually were sleep tested. In previous studies, the data was self-reported. So the data may be, in fact, inaccurate. A lot of the other studies included patients with a sleep disorder called obstructive sleep apnea, which now is very well known to be an independent cardiovascular risk factor in terms of increasing risk of disease, increasing risk of arrhythmias. In this study, they excluded those individuals so that they can focus strictly on sleep alone as a risk factor for cardiovascular disease, so that you don't have other independent risks confounding the data."
What we should take from this study: "One of the things we all value is control. This is yet another risk factor for cardiovascular disease that we actually can control, and we actually can modify by taking better care of ourselves, in terms of diet, exercise, just your overall physical and emotional health. And, sleep is yet another factor in this that I think we all need to pay attention to, to take better care of ourselves. If you don't get good sleep, it's going to catch up to all of us and we're going to pay the price."