If you give a kid a smartphone; kidney signal discovery points to new BP treatments; shingles vaccine could slow dementia – Morning Medical Update

Early smartphones tied to higher depression, sleep problems in tweens

A new Pediatrics study adds fuel to parents’ debates over when kids should get their first phone. Researchers analyzing data from more than 10,500 U.S. children found that those who had a smartphone before age 12 showed higher rates of depression, obesity and insufficient sleep.

Kids who picked up a phone between ages 12 and 13 also developed more mental-health symptoms within a year than peers who remained device-free. The study doesn’t prove causation, but investigators say the findings reinforce concerns that early screen exposure crowds out sleep and healthy routines during a sensitive developmental window. The New York Times has more.

Kidney study uncovers new brake on blood pressure hormone

University of Virginia scientists say they’ve identified how the body shuts off renin — the hormone that cranks up blood pressure — potentially paving the way for new hypertension treatments. Working in intact kidney tissue, researchers observed that angiotensin II triggers bursts of calcium within juxtaglomerular cells, signals that ripple to neighboring cells to suppress renin release.

The study challenges insights drawn from isolated cells and highlights calcium as a key “off switch” in blood pressure control.

Singles vaccine shows surprising benefits for dementia patients

A study out of Wales and Australia, published in Cell, suggests the shingles vaccine may do more than intended — it may slow dementia progression. Researchers tracking more than 282,000 older adults found that vaccination was linked to fewer new mild cognitive impairment diagnoses and, among those already living with dementia, a nearly 30-percentage-point drop in deaths due to the disease over nine years. Read more from CNN Health.