Parents of adult survivors of childhood cancer may harbor deep feelings of protectiveness that continue well beyond the initial treatment and off-treatment periods when the threat of primary cancer recurrence is a realistic concern. This can be manifested in them by accompanying their adult children to doctors' appointments and deserves further study.
Behavioral modifications for the treatment of obesity, including caloric restriction, have notoriously low long-term success rates relative to bariatric weight-loss surgery. The reasons for the difference in sustained weight loss are not clear. One possibility is that caloric restriction alone activates the stress-responsive hypothalamo-pituitary-adrenocortical (HPA) axis, undermining the long-term maintenance of weight loss, and that this is abrogated after bariatric surgery. Accordingly, we compared the HPA response to weight loss in 5 groups of male rats: (1) high-fat diet-induced obese (DIO) rats treated with Roux-en-Y gastric bypass surgery (RYGB, n=7), (2) DIO rats treated with vertical sleeve gastrectomy (VSG, n=11), (3) DIO rats given sham surgery and subsequently restricted to the food intake of the VSG/RYGB groups (Pair-fed, n=11), (4) ad libitum-fed DIO rats given sham surgery (Obese, n=11) and (5) ad libitum chow-fed rats given sham surgery (Lean, n=12). Compared to Lean controls, food-restricted rats exhibited elevated morning (nadir) non-stress plasma corticosterone concentrations and increased hypothalamic corticotropin releasing hormone and vasopressin mRNA expression, indicative of basal HPA activation. This was largely prevented when weight loss was achieved by bariatric surgery. DIO increased HPA activation by acute (novel environment) stress and this was diminished by bariatric surgery-, but not pair-feeding-, induced weight loss. These results suggest that the HPA axis is differentially affected by weight loss from caloric restriction versus bariatric surgery, and this may contribute to the differing long-term effectiveness of these two weight-loss approaches.
Polycystic ovary syndrome (PCOS) is the most common endocrinopathy affecting women of reproductive age. Although a comorbidity of PCOS is obesity, many are lean. We hypothesized that increased saturated fat consumption and obesity would exacerbate metabolic and stress indices in a rodent model of PCOS. Female rats were implanted with the nonaromatizable androgen dihydrotestosterone (DHT) or placebo pellets prior to puberty. Half of each group was maintained ad libitum on either a high-fat diet (HFD; 40% butter fat calories) or nutrient-matched low-fat diet (LFD). Irrespective of diet, DHT-treated animals gained more body weight, had irregular cycles, and were glucose intolerant compared with controls on both diets. HFD/DHT animals had the highest levels of fat mass and insulin resistance. DHT animals demonstrated increased anxiety-related behavior in the elevated plus maze by decreased distance traveled and time in the open arms. HFD consumption increased immobility during the forced-swim test. DHT treatment suppressed diurnal corticosterone measurements in both diet groups. In parallel, DHT treatment significantly dampened stress responsivity to a mild stressor. Brains of DHT animals showed attenuated c-Fos activation in the ventromedial hypothalamus and arcuate nucleus; irrespective of DHT-treatment, however, all HFD animals had elevated hypothalamic paraventricular nucleus c-Fos activation. Whereas hyperandrogenism drives overall body weight gain, glucose intolerance, anxiety behaviors, and stress responsivity, HFD consumption exacerbates the effect of androgens on adiposity, insulin resistance, and depressive behaviors.
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