The last time Dr. Julie Lin went for her annual check-up, she asked for tests of her kidney function that her primary care doctor would not otherwise have ordered.
It was not just that Dr. Lin is a Brigham and Women’s Hospital nephrologist — a kidney specialist — and often sees patients who, by the time their disease has been detected and they have been referred to her, are verging on total kidney failure.
It was that she had found in her own research — which is just out in a leading nephrology journal — that tests of your kidney function can apparently yield surprisingly telltale insights into the health of your brain, and possibly other organs as well.
The research looked at more than 1700 women over age 70 in the long-running Nurses’ Health Study, following them for up to six years. It found that in women whose urine tests indicated the very beginnings of kidney dysfunction, their cognitive abilities — higher-order brain functions like memory and verbal fluency — declined two to seven times faster than normal.
More than half a million Americans are in ‘end-stage’ kidney disease, and among them, 88,000 die each year.
The cognitive experts working on the study were “really struck by how strong an association there was, how much faster a decline this very small amount of protein in the urine is signaling,” Dr. Lin said.
The study mainly raises the possibility of an easy, non-invasive urine screening test that could provide a useful window into brain health. But it also has potential implications for a medical-emotional conundrum: Over 20 million Americans are afflicted by chronic kidney disease; more than half a million are in its ominous “end stage,” and among them, 88,000 die each year. So why, oh why, don’t you care more about your kidneys?