Studying Sleep's Impact on Kidney Health

Ciaran McMullan Young Investigator PhotoA good night’s rest is extremely important to your overall wellbeing and, it turns out, your kidneys.

Researchers have already linked sleep deprivation and sleep disorders to higher rates of diabetes and cardiovascular disease, and now the link between shut-eye and kidney function is becoming clearer with new research by Ciaran McMullan, MD, of Brigham and Women's Hospital.

With the support of a Young Investigators Grant from the National Kidney Foundation, Dr. McMullan is studying how sleep impacts the kidneys and whether more sleep and melatonin supplementation can improve kidney function.

“Kidney function is actually regulated by the sleep-wake cycle. It helps coordinate the kidneys’ workload over 24 hours,” Dr. McMullan said. “We also know that nocturnal patterns can affect chronic kidney disease and that people who sleep less usually have faster kidney function decline. What we’re doing now is looking at the specific hormones that may be behind these declines.”

Dr. McMullan’s research will take a closer look at melatonin secretion, which is the hormone our bodies produce naturally to synch our nocturnal functions. As part of the study, healthy participants will have their sleep restricted and their hormone levels and kidney function will be measured.

The study will also include people who are habitually sleep restricted and will ask them to sleep longer hours to see if it affects their physiology, blood pressure, blood glucose levels and kidney function. Half of this group will also be given melatonin supplements to see if that impacts their kidney function over time.

“So not only are we looking at people’s sleep patterns, we’re trying to see if there may be some interventions that can be taken by people with sleep deprivation,” Dr. McMullan said.

Better understanding how the kidneys work and interact with our hormones at night might also help determine better nutrition guidelines and optimized times for medication delivery. This is because the kidneys’ ability to process medications and nutrients like sodium and potassium changes between day and night.

The study could identify new groups of people who are at higher risk for developing chronic kidney disease due to their lifestyle or work schedule, for example, those who work in shifts and those with chronic sleep deprivation issues.

“It pays to recognize these issues as risk factors because it means these individuals may need more aggressive kidney disease screening and blood pressure management,” McMullan said.