Quality of Life, BMI, and Physical Activity in Bariatric Surgery Patients: a Structural Equation Model.

PURPOSE: The purpose of this study was to use a structural equation model to clarify how physical activity (PA), sex, and BMI relate to quality of life (QoL) of post-bariatric surgery patients. METHODS: The study had a retrospective cohort design for a convenience sample population of 886 bariatric subjects (38 ± 8.49 years). QoL was assessed using World Health Organization Quality of Life-BREF, PA using the International Physical Activity Questionnaire, and BMI values were calculated. Structural equation analysis was conducted in Mplus. RESULTS: The physical domain presented positive relationships with BMI (p = 0.014) and the very active group and negative with the insufficiently active A and B groups and sex (p < 0.001). The psychological domain presented negative associations with BMI and the very active group and positive with the insufficiently active A group. The social relations domain presented negative associations with BMI (p < 0.009) and the very active group (p < 0.002) and positive with the insufficiently active A (p < 0.007) and B (p < 0.019) groups. The environmental domain was negatively associated with BMI (p < 0.004) and the very active group (p < 0.001) and positively with the insufficiently active B group (p < 0.049) and sex (p < 0.018). CONCLUSION: BMI is a negative predictor of QoL in bariatric patients and this trend was not observed in the physical domain only; also, the very active group was negatively associated with QoL. We believe that distortions in body weight/body size extend to PA, and research is needed to explore the psychological factors underlying the overestimation of the amount of PA performed.

Damage of the medial preoptic area impairs peripheral pilocarpine-induced salivary secretion.

The existence of neural connections between the medial preoptic area (MPOA) and the salivary glands and the increase in salivation by thermal or electrical stimulation of the MPOA have suggested an important role of MPOA in the control of salivary gland function. Although direct cholinergic activation of the salivary glands induces salivation, recent studies have suggested that salivation produced by i.p. pilocarpine may also depend on the activation of central mechanisms. Therefore, in the present study, we investigated the effects of bilateral electrolytic lesions of the MPOA on the salivation induced by i.p. pilocarpine. Adult male Holtzman rats (n = 11-12/group) with bilateral sham or electrolytic lesions of the MPOA were used. One, five, and fifteen days after the brain surgery, under ketamine anesthesia, the salivation was induced by i.p. pilocarpine (1 mg/kg of body weight), and saliva was collected using pre-weighed small cotton balls inserted into the animal's mouth. Pilocarpine-induced salivation was reduced 1 and 5 days after MPOA lesion (341 +/- 41 and 310 +/- 35 mg/7 min, respectively, vs. sham lesions: 428 +/- 32 and 495 +/- 36 mg/7 min, respectively), but it was fully recovered at the 15th day post-lesion (561 +/- 49 vs. sham lesion: 618 +/- 27 mg/7 min). Lesions of the MPOA did not affect baseline non-stimulated salivary secretion. The results confirm the importance of MPOA in the control of salivation and suggest that its integrity is necessary for the full sialogogue effect of pilocarpine. However, alternative mechanisms probably involving other central nuclei can replace MPOA function in chronically lesioned rats allowing the complete recovery of the effects of pilocarpine.