Irregular Sleep, Drinking Caffeine After 3PM Could Raise Your Risk Of Heart Attack And Stroke

Updated Dec 1, 2024 | 03:01 PM IST

SummaryConsistency in sleep is more crucial for heart health than simply sleeping enough hours.
Irregular Sleep, Drinking Caffeine After 3PM Could Raise Your Risk Of Heart Attack And Stroke

Irregular Sleep, Drinking Caffeine After 3PM Could Raise Your Risk Of Heart Attack And Stroke

I’ve always struggled with inconsistent sleep, staying up late and waking up at different times each day. My love for coffee was also on an all-time high with trying all the season specials. But it is only recently, I learned how this irregular sleep pattern and caffeine could increase my risk of heart attack and stroke. Now, I’m prioritizing a consistent sleep schedule and cutting out caffeine after 3 PM to protect my heart.

A new, shocking study shows that irregular sleep patterns can greatly increase the risk of heart attack and stroke. But that's not all: the timing of your caffeine intake could also play a critical role in your cardiovascular health. If you are struggling with inconsistent sleep patterns and regularly sipping on caffeinated beverages late in the day, you may be unknowingly putting yourself at risk for serious heart-related issues.

For most people, sleep is something of a given and we often only consider ourselves as long as we get our required seven to nine hours. However, according to a recent study conducted by researchers at the Children's Hospital of Eastern Ontario, it may not be that long after all. The study, which included more than 72,000 participants, found that people with irregular sleep patterns—those who fall asleep and wake up at vastly different times each day—face a 26% higher risk of experiencing a heart attack or stroke. This increased risk persisted even for those who managed to get enough sleep. The study followed up participants for eight years to track heart events such as heart attacks, strokes, and heart failure. The conclusions were clear: irregular sleep, even if it's sufficient in duration, is a major cardiovascular risk factor.

The researchers found that those whose sleep patterns were highly irregular had a significantly greater chance of life-threatening heart issues. The more erratic your sleep schedule, the greater the risk, regardless of how many hours you sleep. In fact, people with irregular sleep schedules showed worse cardiovascular health outcomes, including higher rates of high blood pressure, elevated stress hormones, and poor blood sugar and cholesterol management.

Senior scientist Dr. Jean-Philippe Chaput said "sleep regularity may be more relevant than sufficient sleep duration in modulating MACE [major adverse cardiovascular event] risk." In the study, it shows that our bodies are comfortable with consistency, and a varied sleep schedule may interfere with other processes that keep us healthy, especially the heart.

Is it Caffeine After 3 PM Causing Sleeplessness?

Another daily habit that may be putting your heart at risk is caffeine consumption after 3 PM. According to Dr. Chaput, the experts emphasize the need for a healthy sleep schedule and avoiding caffeine late in the day. Caffeine can stay in your blood for up to eight hours, and its consumption later in the afternoon can disrupt your sleep cycle.

Consistent, good-quality sleep is necessary for maintaining healthy cardiovascular function, and the disruption of this by late-day caffeine intake exacerbates the risks posed by irregular sleep. When you drink coffee, tea, or other caffeinated beverages too late, the stimulant effect on your nervous system makes it harder to fall asleep at a regular time. This can lead to inconsistent sleep patterns, which, as we have seen, can be harmful to heart health.

Dr Chaput insists that humans need to adopt practices that contribute to regularized sleep habits. This can be attained by establishing a proper sleeping and waking schedule, eliminating afternoon intake of stimulants such as caffeine, and making your body clock coincide with the lifestyle one leads.

How Does Poor Sleep Affect Heart Health?

According to the experts, the disturbance due to irregular sleep patterns impacts more than one physiological process involved in the maintenance of the healthy heart. For example, poor sleep can be associated with increased inflammation of the body, weakened immunity, and altered regulation of blood sugar and cholesterol, all of which contribute to increased blood pressure and weakening endothelial function, both associated with an increased risk for cardiovascular diseases. Sleep also plays a very important role in regulating stress hormones. Poor or disturbed sleep results in increased levels of cortisol, the stress hormone, which increases blood pressure and can have negative impacts on cardiovascular health over time.

Scientists hypothesize that these disturbances trigger a series of negative effects that enhance the risk of developing chronic heart conditions, including hypertension, atherosclerosis, or even heart failure.

Tips to Protect Your Heart and Improve Your Sleep

In order to protect your heart, experts recommend several proactive measures to improve your sleep patterns and lifestyle. First, maintain a regular sleep schedule whereby you go to bed and wake up at the same time every day, including weekends. Consistency will keep your body's internal clock in check.

Along with regulating your sleep, paying attention to your caffeine habits is just as important. To reduce your risk of heart disease and stroke, experts suggest avoiding caffeine after 3 PM. If you’re sensitive to caffeine, this rule becomes even more critical.

In addition, the introduction of stress-reducing activities like yoga or mindfulness can also be beneficial to lower cortisol levels, and therefore both sleep and heart health can improve. A diet rich in antioxidants, healthy fats, and low on processed sugars also helps maintain cholesterol levels and reduce inflammation.

Does Your Sleep Environment Also Has A Role To Play

Apart from the timing of caffeine and your sleep schedule, another very overlooked factor is the quality of your sleep environment. Scientists have long known that the environment in which you sleep has a huge impact on the quality of your rest. Poor quality of sleep, even if your sleep schedule is regular, can cause health risks that are very much the same as those that arise from irregular sleep patterns.

Here’s an additional tip: make sure your bedroom is conducive to restful sleep. This means keeping your room dark, quiet, and cool. A temperature of around 65°F (18°C) is ideal for most people. Consider investing in a comfortable mattress and pillows, and avoid screen time at least 30 minutes before bed to allow your brain to unwind.

Irregular sleep, in association with taking caffeine in late parts of the day, can risk heart attack and stroke, but a simple maintenance of a sleep schedule, the reduction of consumption of afternoon caffeine, and sleep environmental awareness can definitely safeguard one's heart along with total health.

Your sleep is more than just a time for rest; it's a vital component of your long-term health, and maintaining consistency in your sleep habits is one of the best things you can do for your heart.

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HbA1c Test May Not Be Accurate For Everyone: Who Should Not Rely On It?

Updated Nov 14, 2026 | 12:15 AM IST

SummaryHbA1c measures how much glucose is attached to hemoglobin in red blood cells, providing an estimate of average blood sugar levels over the previous two to three months. But conditions such as anemia and hemoglobin disorders can affect HbA1c readings by altering the lifespan of red blood cells.
HbA1c Test May Not Be Accurate For Everyone: Who Should Not Rely On It?

Credit: iStock

HbA1c, also known as hemoglobin A1c or glycated hemoglobin, is a widely used blood test to diagnose and monitor diabetes. However, ahead of World Diabetes Day, experts have warned that the test may not be accurate for everyone.

HbA1c measures how much glucose is attached to hemoglobin in red blood cells, providing an estimate of average blood sugar levels over the previous two to three months.

Certain medical conditions and blood disorders can affect its accuracy, making readings appear higher or lower than actual blood sugar levels.

Who May Get Inaccurate HbA1c Results?

Conditions such as anemia and hemoglobin disorders can affect HbA1c readings by altering the lifespan of red blood cells.

"HbA1c can be misleading when conditions alter red blood cell lifespan. Iron, B12 or folate deficiency may falsely elevate HbA1c. Conversely, hemolytic anemia, certain hemoglobinopathies, chronic blood loss, recent transfusion and some kidney conditions can lower it falsely," Dr Manisha Arora, Director of Internal Medicine at CK Birla Hospital, Delhi, told HealthandMe.

Dr Sandeep Kharb, Senior Consultant – Endocrinology at Asian Hospital, added that iron-deficiency anemia can also lead to falsely high HbA1c readings.

Experts also cautioned that HbA1c is not a direct measure of insulin resistance. A person may be insulin resistant even before their HbA1c reaches the prediabetes threshold.

What Medical Conditions And Medications Can Affect HbA1c?

Iron, vitamin B12 and folate deficiencies, chronic alcohol use, high-dose aspirin and severe hypertriglyceridemia may contribute to falsely elevated readings.

Falsely low results can occur with hemolytic anemia, hemoglobin disorders, blood loss, transfusions, pregnancy, kidney disease and erythropoietin therapy.

Certain medicines, including dapsone, ribavirin and some antiretroviral drugs, can also affect HbA1c interpretation. The direction of the error depends on the underlying condition and the testing method.

Can Fasting Blood Sugar Be Normal While HbA1c Is High?

Dr Himika Chawla, Senior Consultant, Endocrinology and Diabetology at PSRI Hospital, told HealthandMe HbA1c reflects average blood sugar over two to three months, while fasting blood sugar measures glucose at a particular point in time.

A person may have normal fasting glucose but experience repeated blood sugar spikes after meals, pushing their HbA1c higher. The reverse mismatch can also occur.

Doctors therefore consider both results and the patient's overall clinical picture before making a diagnosis.

What Test Should Be Used To Diagnose Diabetes?

When HbA1c may not be reliable, doctors can use blood glucose-based tests, including fasting plasma glucose and the oral glucose tolerance test (OGTT).

"First test it should be oral glucose tolerance test," Dr Anoop Misra told NDTV.

For the test, a person eats their usual meals for three days and then fasts for eight to 10 hours before their fasting blood glucose is measured. They then drink 75 grams of glucose mixed in water, followed by another blood test two hours later.

Misra explained that fasting glucose below 100 mg/dL and a two-hour reading below 140 mg/dL are normal. Fasting levels of 100–125 mg/dL or two-hour readings of 140–199 mg/dL indicate prediabetes. Fasting glucose of 126 mg/dL or higher, or a two-hour reading of 200 mg/dL or higher, falls in the diabetes range.

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Why Does Type 2 Diabetes Increase The Risk Of Alzheimer’s Disease? Neurologist Explains

Updated Nov 13, 2026 | 08:00 PM IST

SummaryStudies have linked type 2 diabetes to an increased risk of dementia. In people with type 1 diabetes, severe and repeated episodes of high or low blood sugar have also been associated with a higher risk. Even prediabetes and impaired glucose tolerance can impact long-term brain structure.
Why Does Type 2 Diabetes Increase The Risk Of Alzheimer’s Disease? Neurologist Explains

Credit: iStock

A new review of studies has found that people living with type 2 diabetes have a significantly higher risk of developing Alzheimer's disease.

Researchers from Curtin University conducted a systematic review and meta-analysis of 40 studies. They estimated that if 1,000 people with type 2 diabetes were followed for a year, an average of 4.7 would develop Alzheimer's disease.

Published in Alzheimer's Research & Therapy, a separate analysis found that type 2 diabetes was associated with a 53% higher adjusted relative risk of Alzheimer's disease compared with people without the condition.

How Does Blood Sugar Affect Memory?

Ahead of World Diabetes Day, Dr Sudhir Kumar, neurologist at Apollo Hospitals, Hyderabad, in a post on X, explained that several overlapping mechanisms may link type 2 diabetes to Alzheimer's disease. These include:

  • Brain insulin resistance: Brain cells become less responsive to insulin, potentially impairing their ability to use glucose for energy and clear amyloid and tau proteins.
  • Vascular damage: High blood sugar can damage large and small blood vessels in the brain, increasing the risk of strokes and vascular dementia.
  • Chronic inflammation: Peripheral inflammation and lipid abnormalities can weaken the blood-brain barrier and trigger neuroinflammation.
"Type 2 diabetes is recognized as one of the major modifiable risk factors for dementia. Even prediabetes and impaired glucose tolerance can impact long-term brain structure," Dr Kumar said.

How Does Diabetes Increase The Risk Of Dementia?

According to Alzheimer's Society UK, diabetes is an established risk factor for dementia. The risk also increases with the duration and severity of diabetes. However, having diabetes does not mean a person will necessarily develop dementia.

With diabetes and Alzheimer's disease cases rising globally, understanding the link between the two conditions is becoming increasingly important.

Insulin helps regulate blood sugar by enabling the body's cells to use glucose for energy. In people with diabetes, the body either does not produce enough insulin or cannot use it effectively, causing blood sugar levels to rise.

Studies have linked type 2 diabetes to an increased risk of dementia. In people with type 1 diabetes, severe and repeated episodes of high or low blood sugar have also been associated with a higher risk.

Diabetes and Alzheimer's disease may share certain underlying mechanisms. In both conditions, brain cells can become less responsive to insulin, potentially affecting brain function and contributing to the accumulation of amyloid and tau proteins associated with Alzheimer's disease.

How Can People With Diabetes Protect Their Brain Health?

Dr Kumar recommended the following measures for people living with type 2 diabetes:

  • Maintain blood sugar levels: Aim to keep glucose within your target range.
  • Avoid extreme fluctuations: Prevent prolonged high blood sugar (HbA1c of 7% or higher) and severe, repeated episodes of low blood sugar (hypoglycemia).
  • Manage other health conditions: Keep blood pressure and cholesterol under control.
  • Prioritise a healthy lifestyle: Eat whole foods, including vegetables, fruits and whole grains, and engage in regular physical activity to improve insulin sensitivity.

"Early detection, consistent blood sugar management, and working closely with your healthcare team can help safeguard your cognitive future," he said.

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Delhi Air Pollution: Are Online Classes And Indoor Time Adding To Children's Anxiety?

Updated Nov 13, 2026 | 10:50 PM IST

SummaryAs Delhi-NCR battles severe air pollution, children are being forced indoors for longer duration with online classes and restricted outdoor activities. Experts explained that reduced playtime, disrupted social interactions and increased screen use may contribute to anxiety and affect children's emotional well-being.
Delhi Air Pollution: Are Online Classes And Indoor Time Adding To Children's Anxiety?

Credit: AI Image

Four-year-old Deborah started school this year full of excitement. But she is struggling to understand why she now has to attend classes on a screen. The nursery student misses the school bus, chatting with friends and running around the classroom. Despite the appeal of screens, she finds it difficult to sit still for online lessons.

Coughing badly, she asks what pollution is and pleads with her family to let her play in the park.

Deborah is not alone. Across Delhi-NCR, children are facing similar disruptions as schools shift classes online amid deteriorating air quality, keeping them indoors for longer.

Air pollution in India is no longer just a winter problem. Although levels peak during the colder months, poor air quality has increasingly become a year-round concern, with Delhi-NCR experiencing severe pollution episodes.

Beyond its well-documented respiratory and developmental effects, pollution and the disruption it brings to children's daily lives may also affect their emotional well-being. HealthandMe spoke to health experts, who warned that reduced outdoor play, disrupted social interactions and increased screen time could add to children's psychological stress.

How Air Pollution Can Affect Children's Mental Health

Air pollution should not be viewed as an isolated exposure when examining its impact on children's mental health, said Dr. Pradeep B.S., a Professor of Epidemiology and Deputy Medical Superintendent at the National Institute of Mental Health and Neuro Sciences (NIMHANS) in Bengaluru.

"Air pollution is a macro-level effect. If we reduce it to individual-level effects, we are scientifically wrong," he told HealthandMe on the sidelines of the 11th Together Against Stigma (TAS) Conference, held in the national capital.

He said air pollution is associated with several broader changes, including increased traffic, population growth, climate disturbances and unpredictable weather patterns. Together, these can have a silent effect on people's psychological well-being, including that of children and adolescents.

The effects may not always be direct. Respiratory and gastrointestinal problems, for instance, can prevent children from going outdoors and participating in activities. Losing the opportunity to play can itself become a source of distress.

He also pointed to urbanisation and road expansion, which not only contribute to pollution but also reduce green spaces, playgrounds and community recreational areas. The combination can limit children's opportunities to play, interact and socialise.

Environmental Stress Can Also Affect Children's Emotional Well-Being

Dr. Pallab K. Maulik, the Director of Research at The George Institute for Global Health India said air pollution is one of the contributors to mental health concerns, with both Indian and international research examining the association.

He told HealthandMe that pollution and environmental disasters can create anxiety and stress among children, particularly those whose everyday lives are disrupted by these conditions.

Citing an example from one of his study sites, he recalled speaking to a child living in a slum area whose home gets flooded whenever municipal tankers wash the streets. The child has to spend two days drying her books after the water enters the house.

Dr Pallab also referred to children in the Sundarbans who regularly experience flooding and salinity-related problems.

He said some adolescents are now using platforms such as adolescent parliaments to bring their concerns to local administrators. While children are becoming more aware of environmental challenges, he said, much more needs to be done to understand how environmental changes affect their mental health.

Staying Indoors, Screen Addiction And Anxiety

Dr Syed Hubbe Ali - Health Specialist (RMNCHA) at UNICEF highlighted another possible consequence of pollution-related restrictions on outdoor activities: increased screen exposure among children and adolescents.

When children cannot go outside, they tend to spend more time indoors, often turning to mobile phones, social media and online content. This can create a cycle of screen dependence, he explained.

He described how the pursuit of dopamine, associated with the brain's reward system, can encourage children to keep scrolling through social media content.

The cycle can become more complicated when children begin posting content and seeking validation through likes and engagement.

"Once you start developing your roles, the next stage comes when you see how many likes I got. I got the likes, I don't get the likes. Then the anxiety, you know, it starts," Dr Ali told HealthandMe.

He explained that not receiving the expected engagement can cause distress and, in some cases, contribute to depressive feelings and risky behaviour.

Dr Ali also raised concerns about children spending more time on screens for online learning. Referring to an NCERT survey conducted after the COVID-19 pandemic among 3.7 lakh children, he said only 51% were able to understand online content.

He suggested that learning methods need to move beyond conventional online teaching and incorporate more games and interactive approaches to improve children's engagement.

Why Outdoor Play And Social Spaces Matter

Dr Pradeep emphasised that the impact of pollution cannot be separated from the wider changes taking place in children's surroundings.

Reduced access to green spaces and recreational areas can affect opportunities for physical activity, social interaction and play. When children are unable to participate in these activities, the effects can extend beyond physical health.

Dr Ali also highlighted the importance of outdoor activities and sunlight exposure in children's everyday lives. He said keeping children indoors for prolonged periods can increase their dependence on digital platforms as a source of entertainment and stimulation.

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