By Lisa Rapaport

(Reuters Health) – Adolescents who have high blood pressure are twice as likely to develop serious kidney disease by middle age as teens who don’t, an Israeli study suggests.

The researchers followed almost 2.7 million teens over about two decades starting when they were 17 years old, on average. Nearly 8,000 of the teens, or about 0.3 percent, had high blood pressure but none had signs of kidney disease or damage.

By the end of the study period, about 2,200 people developed end stage renal disease (ESRD), which is kidney damage so advanced that patients typically need dialysis or a transplant to stay alive.

After researchers accounted for other factors that can contribute to ESRD – like age, education levels and obesity – those with high blood pressure, or hypertension, as teens were still twice as likely to develop this chronic kidney disorder by middle age.

“Hypertension is associated with obesity and diabetes and both contribute to the effect on the kidney,” said senior study author Dr. Ehud Grossman, dean of the Sackler Faculty of Medicine at Tel-Aviv University in Israel.

“However, in our study we adjusted for these factors and elevated blood pressure by itself was associated with future renal failure,” Grossman said by email.

The doubled risk of ESRD in middle age held true even after researchers excluded teens with severe hypertension.

Half of the teens with high blood pressure were overweight or obese, and most were male. Yet the risk remained doubled for normal-weight teens with high blood pressure as well.

The study wasn’t designed to prove whether or how teen hypertension might directly cause ESRD.

One limitation on the results is that researchers lacked data on blood pressure during the follow-up period, which might impact the adult risk of ESRD, the study authors note in JAMA Internal Medicine.

“It is possible that high blood pressure and kidney failure are consequences of the same catalyst – such as a genetic variant or an undiagnosed kidney disease,” said Dr. Amy Kogon of the Children’s Hospital of Philadelphia and the Perelman School of Medicine at the University of Pennsylvania.

“The important take-home message for parents and patients is to maintain a lifestyle that reduces the risk of developing hypertension,” Kogon, who wasn’t involved in the study, said by email.

Both hypertension and ESRD are rare in young people, but parents should still focus on prevention, said James Gangwisch, a researcher at Columbia University Medical Center in New York City who wasn’t involved in the study. These conditions that were once seen almost exclusively in adults are becoming more common at earlier ages, he said by email.

“The fact that we are now seeing these conditions in adolescents is troubling,” Gangwisch said. “Behaviors such as getting adequate physical activity, eating a healthy diet and getting sufficient sleep can both prevent and treat hypertension.”

When teens do develop high blood pressure, treating it quickly with lifestyle changes and medication may help ward off future health problems, said Dr. Csaba Kovesdy of the University of Tennessee Health Science Center in Memphis.

“High blood pressure is easy to diagnose and relatively easy to treat,” Kovesdy, who wasn’t involved in the study, said by email. “While the risk of ESRD associated with hypertension is real, treatment of high blood pressure is especially important for the prevention of future strokes and heart attacks.”

SOURCE: JAMA Internal Medicine, online February 25, 2019.