Sairam Parthasarathy, MD: How Sleep Disturbances Impact Immune Function

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In an interview with HCPLive, Parthasarathy discussed the relationship between sleep disturbances and immune function.

Sleep does more than eliminate exhaustion and improve brain function, physical health, and energy conservation—it impacts immune function.

At SLEEP 2024, the 38th annual meeting of the Associated Professional Sleep Societies, Sairam Parthasarathy, MD, from the University of Arizona, presented on the impact of sleep disturbances on the immune system with a focus on sex differences and the implications for Long COVID.1

HCPLive sat down with Parthasarathy to discuss his presentation, and he provided insight into the relationship between sleep disturbances and immune function.

Parthasarathy explained sleep is closely tied to the immune system. When people have sleep disruption, their white blood cells, T lymphocytes, and B lymphocytes, do not function as well. Previous studies found when the white blood cells are not working properly, the individuals have immune dysfunction. For instance, a 2020 study saw lymphocyte, CD4+ T cell, CD8+ T cell, NK cell, and B cell counts were lower in the severe COVID-19 group.2

“They also age because there is a biological age and there’s a chronological age,” Parthasarathy said. “When people don't sleep well, such as individuals with insomnia, there is senescence. They actually age faster, even though their chronological age may be 40 years old, their cells are actually aging at a faster pace, which is their biological age.”

He continued by saying telomere shortening is observed in the cells, meaning aged cells are fighting off a “foreign infection.”

The aged cells explain why older adults, aged 60 and 70 years, had a greater mortality risk with COVID-19 opposed to individuals in their 20s.

“We know that aging was almost like math—it was a linear relationship,” Parthasarathy said. “The older you are, the more likely you are to die from COVID infection.”

However, this was before the vaccination. This was why older adults aged ≥ 65 years were prioritized to receive the vaccination following healthcare workers and first responders.

“So, we know that essentially, the immune cells don’t work,” Parthasarathy said.

Parthasarathy's relevant disclosure includes Jazz Pharmaceuticals.


  1. Engert, L, Parthasarathy, S, Prather, A. The Impact of Sleep Disturbances on the Immune System: The Modulating Role of Sex and Implications for Long COVID. Session presented at SLEEP 2024. Houston, TX. June 3, 2024.
  2. Song CY, Xu J, He JQ, Lu YQ. Immune dysfunction following COVID-19, especially in severe patients. Sci Rep. 2020;10(1):15838. Published 2020 Sep 28. doi:10.1038/s41598-020-72718-9