Heart health and blood pressure: Study finds why even six hours of sleep or weekend catch-up sleep may not be enough

So why can’t we undo the damage caused by daily sleep deficit?

Explains Dr Virendar Sarwal, Director, Department of Cardiovascular and Thoracic Surgery, IVY Hospital, Mohali, “The logic is simple. This eight-hour sleep at night is required to heal the body from the inflammation it experienced during the day. It helps both heart and brain health and aids in recovering the wear and tear the body suffers during the 16 hours in a day. Lack of sleep leads to burnout and causes heart issues as we are witnessing these days.” Weekend rest, he adds, does not help because daily healing has not happened, and the heart keeps getting damaged till it succumbs finally. “The simple principle is to let it heal daily as residual inflammation results in changes in blood pressure, heart rate and loss of oxygenation to body tissues. Both are dangerous for heart and brain health,” he adds. 

How can lack of sleep cause obesity, diabetes and cardiovascular diseases? 

Dr Sandeep Bansal, Professor, Department of Otolaryngology and Head Neck Surgery, PGIMER, Chandigarh, says we often tend to focus on short-term consequences like lack of concentration, fatigue, irritability and memory issues, which we think we can control.  “But over time, sleep deficit leads to and aggravates chronic health conditions like obesity, diabetes, cardiovascular diseases and hypertension. It also increases the likelihood of developing neurodegenerative disorders such as Alzheimer’s disease. Inadequate sleep weakens the immune system,” says he. That’s because shifting around sleep cycles results in measurable differences in body metabolism. “There’s excess calorie intake after dinner, reduced energy expenditure, increased weight and detrimental changes in how the body uses insulin. Even if you resolve sleep debt on paper, the small-time damage through the week has been done,” adds Dr Bansal.     

How much duration of sleep per day is necessary for an adult healthy individual?  

According to Dr Vijayvergiya, the duration may vary depending on age, overall health of an individual and the surrounding environment but that seven to nine-hour window of rest is mandatory.  “We need uninterrupted sleep at night. Splitting the total duration between day and night would adversely affect the sleep cycle, which leads to unfavourable, long-term health issues. That’s because certain hormones are released at night only, hence their impaired release due to sleep deprivation is associated with high blood pressure and heart rate, increased body weight and insulin resistance, leading to Type 2 diabetes.  An increase in stress hormones, generalised inflammation, and impaired endothelial (inner luminal lining of arteries) functions of blood vessels adversely affect cardiovascular health, leading to increased atherosclerosis and heart attacks.  Other than these metabolic changes, sleep deprivation also affects mental alertness and concentration, cognitive performance and emotional well-being,” says he.

Is an afternoon nap during office hours beneficial?  

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A quick daytime nap, which is strategically managed, can be of some benefit. “It should be less than 30 minutes, preferably after lunch when the mental alertness is somewhat lowered for a short duration. In case the afternoon nap is extended for a long duration, associated with a lack of physical and mental alertness after the nap, then it could affect sleep quality at night,” says Dr Vijayvergiya.

How do we plan our social life to maintain a healthy sleep regime?

Just prioritise, plan and balance the weekend parties with physical/mental rest. A few other contributory factors such as transition stress and excess consumption of alcohol, caffeine and smoking also lead to low energy and disrupt sleep cycles, according to Dr Vijayvergiya.