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With one third of the adult American population being obese, it is no surprise that there are 113,000 bariatric surgical cases per year. Studies have shown how the procedure can improve obesity-related disorders, such as diabetes mellitus, hypertension, and high cholesterol levels. Researchers are adding another to this growing list – premature aging. In a paper presented at the recent European Society of Cardiology Frontiers In Cardiovascular Biology Conference in Florence, Italy, Austrian researcher Philipp Hohensinner and his collaborators discussed the role of bariatric surgery in improving and possibly reversing the premature aging phenotype of previously morbidly obese patients.
Seventy-six obese patients were followed pre- and post-bariatric surgery. Blood samples were collected prior to the surgical procedure, which decreases the size of the stomach in hopes of inducing a feeling of early satiety and thereby decreasing the likelihood of over-consumption. Blood samples were then repeated one and two years post-operation. Researchers focused on assessing markers associated with premature aging and inflammation, namely SASP IL6(1) and PAI-1(2), in addition to telomere length and telomere oxidation.
Telomeres are distinctive stretches of DNA found at the end regions of chromosomes. They provide stability to the chromosomal structure, protecting it from degradation. As we age, telomeres eventually reach a critical length at which point they are no longer able to replicate, signaling apoptosis (cell death). Previous studies have shown reduced telomere length to be associated with cellular aging. Additionally, oxidative stress has been shown to accelerate the rate of loss of DNA within the telomere region of the chromosome.
Not only did the surgical patients drop the pounds drastically, with a significant reduction in BMI from 44.5 to 27.5, plasma levels for IL6 and PAI-1 showed a statistically significant decrease 12 months post-bariatric surgery. There was also a reported increase in the anti-inflammatory cytokine interleukin-10. Dr. Hohensinner speculated that the loss of significant amounts of adipose tissue appeared to shift the cellular environment from a pro-inflammatory state to a healthier one.
Researchers also found a 58 percent increase in telomere length, as well as a significant reduction in the telomere oxidation index. In samples taken two years post-bariatric surgery, oxidative damage to the telomeres had been reduced by three-fold. The authors attributed the increase in telomere length to the reduction in oxidative stress across the telomere regions of the chromosomes. They noted that active elongation of the telomere is unlikely, because the decreased telomere oxidative index found across the study participants is more suggestive of decreased breakage of the telomeres.
Depending on how these findings are utilized, researchers may eventually have the ability to impact the lives of those suffering with obesity and its related complications. However, with such a small cohort, one would anticipate the next step being a larger clinical trial to bolster these findings.
Nonetheless, the potential patient outcomes from this study should be noted. It is best placed into context with the following statement from Dr. Hohensinner: “This is positive news for patients who have bariatric surgery because it shows that the damage from obesity can be reversed. Surgery is the last resort for these patients and it is good to see that not only do they lose weight, but they also reduce the stress on their body and reduce the premature aging.”
NOTES:
SASP IL6: Senescence associated secretory phenotype turns senescent fibroblasts into proinflammatory cells that have the ability to promote tumor progression. Interleukin 6 is the most prominent cytokine of the SASP.
PAI-1: Plasminogen activator inhibitor type 1 is a serine protein inhibitor that is secreted in response to inflammatory reactions.
