January can be a dark month. The weather is cold, the sky is gray and there is a constant spike in heart attacks.
Researchers have found that people are more prone to heart attacks in January and December than in other months of the year. This phenomenon does not seem to be related to the weather, and scientists are trying to learn why more people succumb to heart problems during this time.
Scientists are urging people to learn the symptoms of a heart attack and not to ignore any warning signs — especially during heart attack season.
Read more: What happens when hearts attack
The deadliest time of the year
Studies have found that most heart attacks occur on Christmas Day, followed by December 26th and January 1st. At first, scientists thought the increased cases were due to the cold weather. Then, 2004 study in the diary Circulation tried to see if cardiac deaths were related to the holidays rather than falling mercury.
The study authors looked at a database of death certificates from 1973-2001 The National Center for Health Statistics (NCHS). They note what time of year the death occurred and how the person passed. They considered all types of death, not just heart-related mortality.
The researchers then combined cardiac deaths for all years in the sample and created a chart that showed the frequency of which days in the calendar year those events occurred. The result was a chart that looked like a hill. Cardiac deaths were lower in July, increased as the year progressed and then peaked at Christmas. There was a slight dip and then another peak on January 1st. Cardiac mortality remained high in January and then began to decline in the spring and early summer.
Public health researchers around the world also question whether their country has a heart attack season. IN 2018 article in BMJ, scientists suspected that Sweden saw a spike in heart attacks during the winter holidays. They examined data from 1998 to 2013 on heart-related deaths for the two weeks before Christmas and the two weeks after. They also looked at data from events over the summer, including the Olympics and the FIFA World Cup.
The study found that the overall risk of heart disease increased by 15 percent between Christmas and New Year. The risk is greater for people 75 and older, diabetics, and people with a history of coronary artery disease.
There was no association between heart attacks and sporting events in the summer, which might be expected due to Sweden’s problems at the World Cup in the years in the data sample.
Similar research in Norway found that heart attacks increased on December 22 and continued at a higher rate in January. And research in New Zealand – which experiences summer in December and January – late December and early January were also found to be a time of increased cardiac events.
Heart attack season
Scientists have found that there is a heart attack season associated with December and January. But they’re not sure why there are more heart-related deaths during those months.
The authors of the 2004 Circulation article explores several possible explanations. Falling temperatures during the winter months have long been blamed for cold weather heart attacks increases blood pressure and restricts blood vessels. But the study found an increase in heart attacks in Los Angeles, which has relatively mild winters, and a slight decrease in states bordering Canada, where cold winter temperatures are typical.
Read more: Repairing damage after a heart attack
Rather than blame the weather, the study authors suggest that more heart attacks may have occurred during the holidays because people ignore symptoms and delay treatment. Other studies have found that emergency room and urgent care admissions decrease on holidays and increase the following day.
The authors suggest that people do not want to interrupt or spoil the holiday for others. If a person feels a tingling in their arm or a growing pain in their chest, they may attribute it to indigestion from holiday overindulgence. Or they may keep quiet about their symptoms until the urgency becomes apparent to others.
Thus, the authors conclude, the “holiday-induced delay” in seeking medical treatment can have fatal consequences.