• >962 million individuals are aged 60 and over
  • Lymphocyte count can determine upcoming grave illnesses and sudden demise risk
  • Individuals with lower lymphocyte count were 1.6 times increased mortality risk

With the increase in the aging population, there is a constant rise in the health care system demands. A new study reported that a simple blood test can predict the risk of imminent death.

The researchers from the University of Copenhagen, who sought to study 108,135 Danish individuals in the age group 20-100, noted that 10,372 people had died during the study period. When they analyzed the health records of these people, they found abnormal blood test results.

Key findings of the study include: 1) People who had died during the study period had lower levels of a white blood cell known as a lymphocyte; 2) Individuals with lower lymphocyte count were 1.6 times increased mortality risk; and 3) A low lymphocyte count might be associated with an early demise.

Low lymphocyte count (lymphopenia) can be attributed to several reasons including risks of cancer, respiratory diseases, infections, heart diseases, and other causes. Since chronic diseases are quite common among older individuals, their low lymphocyte count can indicate an early demise.

Lymphopenia is diagnosed when an otherwise healthy individual undergoes a routine blood test. Quite often, individuals with this condition aren’t referred for further evaluations since the mortality implications have been unknown.

The findings of the study indicated that lymphopenia at a high risk of dying from any cause, regardless of other risk factors including age and gender.

"This might be due to reduced immune surveillance, which makes these patients less able to survive potentially deadly diseases. Lymphopenia could also be a more passive marker of general frailty that confers a high risk of death from any cause. Older age is associated both with decreasing lymphocyte count, which we found in this study and with mortality," the researchers said.

What causes an age-associated decline in lymphocyte count remains unclear. However, possible explanations include age-related thymic involution which leads to a change in the composition of the white blood cells which leads to a change in overall immune competence. The high risk of sudden demise among those younger than 70 years of age suggests that factors apart from one’s age might also contribute to the mortality risk including blood donations, transfusions, or poor immune surveillance.

Blood testing
A medicine diagnostician takes a blood test Getty Images/Christof Koepsel/Bongarts