Longitudinal changes in telomere length in a cohort of obese patients submitted to bariatric surgery: a 2-year follow-up

Background Telomere length (TL) is one biomarker of cell aging used to explore the effects of the environment on age-related pathologies. Obesity and high body mass index have been identified as a risk factors for shortened TL. Objective To evaluate TL in different subtypes of obese patients, and to examine changes in TL in relation to weight loss after bariatric surgery. Setting University Hospital in Spain. Methods A cohort of 94 patients submitted to bariatric surgery were followed-up during 24 months (t24m: lost to follow-up = 0%). All patients were evaluated before surgery (t0) and during the postoperative period (t6m, t12m, and t24m) for body mass index and metabolic variables. We assessed TL at each timepoint using quantitative polymerase chain reactions and the telomere sequence to single-copy gene sequence ratio method. Results Patients with class III obesity showed significantly shorter TL at baseline than those patients with class II obesity (P = .027). No differences in TL were found between patients with or without type 2 diabetes or metabolic syndrome. Longitudinal analysis did not show an effect of time, type of surgery, age, or sex on TL. However, a generalized estimating equation model showed that TL was shorter amongst class III obesity patients across the time course (P = .008). Comparison between patients with obesity class II and class III showed differences in TL at t6m (adjusted P = .024), whereby class II patients had longer TL. However, no difference was observed at the other evaluated times. Conclusion Obesity severity may have negative effects on TL independently of type 2 diabetes or metabolic syndrome. Although TL is significantly longer in class II obesity patients relative to class III 6 months after bariatric surgery. This difference is not apparent after 24 months.