ATLANTA – Gastric bypass was associated with the lengthening of telomeres, an indication that surgical weight loss may reverse aging in obese patients.
The most significant changes in telomere length occurred in patients with biomarkers indicative of higher levels of preoperative inflammation and cholesterol, according to findings presented by bariatric surgeon John Morton at this year’s Obesity Week.
"Telomeres are unique markers for aging and are linked to chronic diseases and things like smoking and depression," Dr. Morton said in an interview. "There are a lot of things that can potentially affect telomeres, but there aren’t a lot of things that can affect them in a positive sense."
Dr. Morton and his colleagues at Stanford (Calif.) University measured the baseline telomere length, weight, C-reactive protein (CRP) levels, cholesterol levels, and fasting insulin levels in 51 gastric bypass surgery patients (77% female, average age 49 years). The group’s mean body mass index was 44 kg/m2. The measurements were taken again at 3, 6, and 12 months. Telomere length was determined using quantitative polymerase chain reaction testing.
Dr. John M. Morton
In all patients, excess body weight loss at 12 months averaged 71%; CRP levels, indicative of inflammation, dropped an average of more than 60%. Fasting insulin levels decreased from 24 uIU/mL at baseline to 6 uIU/mL when measured 1 year after surgery. These results were consistent with those of previous studies, but this study was the first to correlate such changes with the body’s biomarkers for aging, telomeres, Dr. Morton said.
Unexpected results
Telomere length did not change significantly across the cohort, but when analyzed according to CRP and LDL levels, significant changes in telomere length were found in patients whose levels of both were higher at baseline (P = .0387 and P = .005). In those whose baseline CRP was high, there also was a significant positive correlation between telomere lengthening and weight loss (P = .0498) and increases in HDL cholesterol level (P = .0176).
The results were somewhat unexpected. "The thing that surprised me the most was that if there were going to be changes, then they should be across the board," said Dr. Morton. "But where it really made a difference was in those who had [high levels of markers of] inflammation. It was a pretty specific result in a pretty specific population."
At least one other longitudinal study has shown the impact of nonsurgical intervention, namely a change in diet, on the length of telomeres (PLoS One 2013;8:e62781[doi:10.1371/journal.pone.0062781]), but Dr. Morton said the study, which emphasized eating less red meat and more fish, fresh vegetables, and olive oil did not demonstrate results that were notably different from his findings.
"One thing that study’s diet, the Mediterranean Diet, is known to do is to raise HDL," said Dr. Morton. "In our study we also saw a correlation between telomere lengthening and increases in HDL. That’s really hard to do. There aren’t a lot of medicines that can really affect the ‘good’ cholesterol."
‘Unique ability’ of gastric bypass
The study did not examine the relationship between telomeres and other kinds of surgical interventions for weight loss, but Dr. Morton said future studies on bariatric procedures such as the sleeve gastrectomy need to be conducted before they can be equated with bypass.
"Gastric bypass has a unique affect on inflammation that is independent of the other operations," said Dr. Morton, referring to data he presented earlier this year at the American College of Surgeons annual meeting, discussing the relationship between bypass and diabetes. "We have shown that C-reactive protein decreases more with gastric bypass than with other operations."
That of all the surgical interventions, gastric bypass has the greatest impact on diabetes, independent of weight loss, points to future research on inflammation, said Dr. Morton. "People are starting to think that type 2 diabetes is not just a burned-out pancreas, but that a lot of inflammation is involved."
Calling bariatric surgery a "platform for investigation" that can help [us] understand the connection between inflammation and the processes of disease in the general population, not just those with obesity, Dr. Morton said, "I think the future will elucidate some of those processes, and will come up with different interventions such as drugs."
Dr. Morton said he did not have any relevant financial disclosures.