Franny Jongbloed

148 CHAPTER 6 Bariatric surgery may be indicated as a treatment for morbidly obese patients 25 . Besides rapid loss of body weight, bariatric surgery has been reported to reverse obesity-related diseases including diabetes mellitus and dyslipidemia 25 . Whether this procedure also induces reversal of aging, in particular premature T-cell aging, is unclear. Therefore, we aimed to determine the effects of morbid obesity and MetS on aging of circulating T-cell subsets as well as the potential reversal of T-cell aging by bariatric surgery. We show that the presence of MetS is an individual risk factor for premature aging of the T-cell immune system of morbidly obese patients and a partial reversal of the aging process may be established by bariatric surgery. These data show that MetS predisposes to accelerated T-cell aging and may be a biomarker identifying patients that benefit from bariatric surgery. RESULTS Baseline characteristics A total of 118 participants were included in this study, consisting of 10 HC and 108 morbidly obese patients. Of the latter, 41 persons with a BMI of ≥35 did not have MetS and 67 had MetS. Table 1 summarizes the baseline characteristics of the included participants. Patients without MetS were more often female than patients with MetS. When dividing the groups in patients ≤50 and >50 years, patients with MetS were significantly older in the group ≤50 years. No significant differences were observed with respect to distribution of CMV- seropositivity amongst the study groups. Lower numbers of recent thymic emigrants due to MetS and age In both CD4 + and CD8 + T-cell compartments, no significant differences were induced by obesity and MetS (Table 2). No age-related decline in CD4 + RTE in the total group was observed, however the group without MetS did show a significant decline. The effects were stronger in the CD8 + T-cell population, which showed an age-related decline in RTE for morbidity obese patients as well as for patients with and without MetS (Table 2). These data suggest an age-related decline in RTE which is most significant in the CD8 + T-cell compartment and intensified by the presence of MetS. CMV-seropositivity had no effect on RTE. Female patients had a significantly higher number of CD4 + RTE compared to male patients, whereas no significant differences were observed for CD8 + RTE (Table 2).