Condiciones psicológicas preoperatorias y su efecto sobre la pérdida de peso durante los primeros 18 meses postquirúrgicos en pacientes obesos sometidos a bypass gástrico

Objective: To determine whether the preoperative presence of adverse psychological conditions affects weight loss in patients undergoing gastric bypass. Methods: Historical cohort study. Weight loss was expressed as a percentage of excess BMI lost (%EBMIL). Using models of Generalized Estimating Equations (GEE) and Cox proportional hazards, we compared the post-surgical evolution of %EBMIL and the time in which successful weight loss was achieved (%EBMIL ≥50%) among subjects who had psychiatric disorders and/or traumatic life events and those who did not have these conditions before surgery. Results: Of the 155 patients studied, 35.5% had psychiatric disorders and 26.5% had traumatic life events before surgery. Both in the subjects that had psychiatric disorders or traumatic life events and in those who did not have these conditions, the probability of achieving successful weight loss between 12 and 18 months post-surgery was approximately 80%. The absence of psychiatric disorder before surgery decreased the %EBMIL by 3% with respect to preoperative presence of psychopathology, although this decrease was not statistically significant (p =0.08). The absence of previous traumatic life event increased the %EBMIL by 2.9% compared to the preoperative existence of this condition, although this increase was not statistically significant (p =0.06). Conclusions: Psychiatric illness and traumatic life events prior to gastric bypass do not adversely affect weight loss post-surgery. Thus, surgery is not contraindicated.