Cellular aging accelerated in overweight adolescents with high-sodium diets

High dietary sodium intake is associated with shorter telomere length, which may expedite cellular aging, in overweight and obese adolescents, according to new study findings.

“High sodium intake and obesity may act synergistically to accelerate cellular aging,” Haidong Zhu, MD, PhD, from the Medical College of Georgia, Georgia Regents University, and colleagues wrote in an abstract presented at the American Heart Association’s Epidemiology and Prevention/Nutrition, Physical Activity and Metabolism Scientific Sessions.

Researchers said the effect of a high-sodium diet on telomere length was undetermined, so they tested a hypothesis that high dietary sodium intake would be inversely associated with leukocyte telomere length, particularly in the context of obesity, according to the study background.

Zhu and colleagues assessed leukocyte telomere length by a quantitative chain reaction methods in 766 adolescents aged 14 to 18 years (50% girls, 49% black). They assessed diet by three to seven 24-hour recalls and physical activity by accelerometry.

Participants were stratified by low or high sodium intake and by weight.

After controlling for age, sex, race, energy intake, Tanner stage and vigorous physical activity, leukocyte telomere length was significantly shorter in overweight and obese participants with high sodium intake compared with those with low sodium intake (1.24 vs. 1.32; P=.02). However, the researchers found no difference in telomere length among normal-weight participants (high-sodium group, 1.29; low-sodium group, 1.3; P=.69).

Additionally, higher dietary sodium intake was associated with shorter leukocyte telomere length in overweight or obese participants (beta=–0.37; P=.045), but not in normal-weight participants, according to multiple linear regression analyses.

“Lowering sodium intake may be an easier first step than losing weight for overweight young people who want to lower their risk of heart disease,” Zhu said in a press release.

Elliott Antman

In a commentary posted on the AHA website, Elliott Antman, MD, of Brigham and Women’s Hospital and Harvard Medical School, called the findings “a particularly disturbing observation.

“We don’t really know why the combination of obesity and a high-sodium diet is especially bad and really accelerates the shortening of the telomere lengths,” Antman, who is president-elect of the AHA, wrote. “But it’s an important observation and adds additional support for the recommendations to lose weight and eat less sodium.”

For more information:

Zhu H. Abstract #MP64. Presented at: the American Heart Association Epidemiology and Prevention/Nutrition, Physical Activity and Metabolism 2014 Scientific Sessions; March 18-21, 2014; San Francisco.

Disclosure: The researchers and Antman report no relevant financial disclosures.