No abstract

Background: The desynchronization of central and peripheral clocks with the environment leads to the circadian misalignment. Social jetlag (SJL)-a chronobiological variable which measure the level of this misalignment-has been associated to a higher risk of developing obesity, metabolic diseases and a worse food consumption pattern. However, the influence of circadian misalignment on anthropometrics, dietary and metabolic outcomes has not been studied in patients undergoing bariatric surgery. Objective: To evaluate the influence of SJL on anthropometric, metabolic and food intake outcomes in patients undergoing bariatric surgery throughout six months follow-up after surgery. Methods: Hundred twenty-two bariatric patients were included in the study (77% female, 79.5% underwent Roux-en-Y gastric bypass technique, age: 33 [28.0-41.7]). Anthropometrics and food consumption variables were evaluated in the preoperative, third and sixth months after surgery, while the metabolic variables were evaluated in preoperative and sixth month after surgery. Generalized estimated equations were used to evaluate the influence of follow-up time and degree of exposure to SJL and the interaction between both on the outcome's evolution. Linear regression was performed to evaluate the association between the mean of degree of exposure to SJL during the six months of follow-up and the delta of anthropometric and metabolic variables. Results: Linear regression showed a negative association between the mean of SJL exposure during the six months and the weight loss in kilos (β=0.17, p=0.17), weight loss percentage (β=-0.30, p=0.006), the reduction of body mass index (BMI) (β=-0.24, p=0.007), waist (β=-0.17, p=0.04) and hip (β=-0.39, p<0.001) circumferences. GEE analyses showed a negative effect of the interaction between SJL exposure and the follow-up time on weight (p=0.01), BMI (p=0.04) and insulin (p=0.01), as well as an isolated effect of SJL on calories (p= 0.001), carbohydrates (p=0.005), total fat (p=0.007), monounsaturated (p=0.03) and polyunsaturated fat (p<0.001) intake. Conclusion: SJL presented a negative effect on anthropometric, metabolic and food consumption outcomes variables after six months of bariatric surgery. Future studies on this subject are necessary to confirm these findings.