My patient’s LDL cholesterol shot up despite eating right and 30-minute walks: Was his work schedule the reason?

Why daytime sleeping, even for long hours, can still affect your heart health?

First of all, disrupting your natural circadian rhythm (the body’s internal clock which regulates cycles of alertness and sleepiness by responding to light changes in the environment, mostly natural light), prevents crucial physiological rest, such as the necessary drop in blood pressure and heart rate. Sleeping during the day, even for six hours, does not align with the body’s natural clock, which regulates metabolism and heart function.

When you sleep normally at night, blood pressure drops by 10-20%. When this natural rhythm gets disrupted, the heart has to work harder and increases stress on blood vessels. This is linked to higher blood pressure, inflammation and a greater likelihood of coronary artery disease.

Also, “catch up” sleep or compensatory sleep cannot quite effectively reverse the cardiovascular strain of missed nighttime sleep. Studies indicate an 8–20% increased risk of heart disease and cardiovascular mortality among shift workers, with risks increasing significantly after 5–10 years.

What shifts take place in the body?

As I mentioned, the first thing to monitor is your blood pressure patterns. High BP and inflammation affect blood vessels in the heart. This leads to damage, making it easier for plaques to dislodge and rupture, causing blockages. As the body’s internal clock regulates metabolism and night shifts disrupt this, there are hormonal changes. The body forcefully reduces sleep-producing hormones and increases cortisol, a stress hormone that leads to higher cholesterol and triglycerides.

Also, humans are not designed to efficiently process food at night, so fat and cholesterol levels go up if you have heavy meals or indulge in stress eating this time. Together, these changes speed up atherosclerosis, the gradual build-up of fatty deposits inside arteries that restrict blood flow to the heart. The night meals also lead to changes in blood sugar metabolism, leading to weight gain and diabetes over time. Both are risk factors for heart disease.

Working nights can build up stress and anxiety faster, again a risk factor. For women, the risks tend to be greater. Hormonal factors influence how the cardiovascular system reacts to stress, and when these are combined with their dual household or caregiving roles, their rest and sleep are both compromised.

How then to protect the heart health of night shifters?

Whatever happens, the person must have uninterrupted seven to eight hours of sleep. Choose a room that’s not likely to be used by others in the daytime, use blackout curtains and eye masks and sleep at the same time every day, building up a new sleep routine. This way the body won’t get confused easily.

Skip fatty meals and snacking at night. Choose lighter, freshly cooked foods with fibre and protein. A brisk walk or some light exercise for half-an-hour during off-duty hours can keep the blood flowing and relax you. Stop relying too much on coffee or energy drinks to stay awake as they put pressure on the heart.

Finally, be thorough with your regular check-ups: Monitor blood pressure, sugar and cholesterol to detect any problems before they escalate. Making small preventive changes is way better than emergencies when it comes to heart health.

(Dr Shetty is lead cardiologist and medical director, Sparsh Hospitals, Bengaluru)