People living with HIV experience shorter sleep cycles, with associated health risksCredit: Yanyong/istock/Getty Images Plus
People living with HIV (PLHIV) have a significantly delayed internal body clock, consistent with the symptoms of jet lag, a study published in the Journal of Pineal Research shows. Researchers at the University of Cape Town, the University of the Witwatersrand (Wits) South Africa, and international colleagues studied people living in the Mpumalanga province, South Africa where nearly one in four people is living with HIV.
They found that physiological daily rhythms, as measured by the hormone melatonin, were delayed by more than an hour on average in HIV positive participants. Their sleep cycle was also shorter, as their sleep started later and finished earlier.
This may contribute significantly to increased burden of health problems experienced by people living with HIV including risk of cardiovascular, metabolic, and psychiatric disorders.
Karina Scheuermaier, co-author of the study and head of the Wits Sleep Lab, explains that melatonin is one of the most robust markers of our internal 24-hour rhythms, which are generated by our master clock in the brain.
“It rises a couple of hours before our usual bedtime, stays high for a couple of hours during our habitual sleep and then start decreasing a couple of hours before our wake time. This rhythm is just one of the rhythms which are synchronized by the master clock.
“This synchronization is meant to best fit our needs: for example, increasing our internal temperature to prepare us for activity when we wake up, making our cells sensitive to the hormone that allows our cells to incorporate sugar (insulin) when we eat, lowering our breath and blood pressure during our sleep.” However, when we sleep earlier in our melatonin cycle, is like jetlag.
Dale Rae, study co-author and head of UCT’s Chronobiology and Sleep Laboratory in the Division of Exercise Science and Sports Medicine, says perhaps people with HIV are going to sleep earlier than their natural body clock (circadian rhythms) tell them to, because of the inflammatory processes or infection itself.
Usually this is a positive response, because it forces a person to sleep more when ill. “But in our study, it seems to be contributing to a circadian misalignment. Another possibility is that other conditions (co-morbidities) with HIV, such as pain or depression, may increase sleep,” says Rae.
