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Biomedical subjects

Per Södersten

Publications and source records attributed to Per Södersten.

8 recordsLinked to original sources
PubMed2006

Understanding eating disorders.

The outcome in eating disorders remains poor and commonly used methods of treatment have little, if any effect. It is suggested that this situation has emerged because of the failure to realize that the symptoms of eating disorder patients are epiphenomena to starvation and the associated disordered eating. Humans have evolved to cope with the challenge of starvation and the neuroendocrine mechanisms that have been under this evolutionary pressure are anatomically versatile and show synaptic plasticity to allow for flexibility. Many of the neuroendocrine changes in starvation are responses to the externally imposed shortage of food and the associated neuroendocrine secretions facilitate behavioral adaptation as needed rather than make an individual merely eat more or less food. A parsimonious, neurobiologically realistic explanation why eating disorders develop and why they are maintained is offered. It is suggested that the brain mechanisms of reward are activated when food intake is reduced and that disordered eating behavior is subsequently maintained by conditioning to the situations in which the disordered eating behavior developed via the neural system for attention. In a method based on this framework, patients are taught how to eat normally, their physical activity is controlled and they are provided with external heat. The method has been proven effective in a randomized controlled trial.

Anorexia↗
PubMed2003

Anorexia nervosa: towards a neurobiologically based therapy.

Eating disorders, i.e. anorexia and bulimia nervosa, are disorders of eating behavior and body weight regulation. Most likely because there are few, if any, effective treatments, eating disorders are considered to be chronic disorders interrupted only by intermittent periods of short-lived remission. The neurobiology of eating, most of which explores hypothalamic mechanisms, has had no influence on the treatment of eating disorders, with the exception of psychopharmacology. However, while most patients are treated with psychoactive drugs, there is no evidence that these are effective. This may be because pharmacological attempts so far have targeted the wrong symptoms. We review the symptomatology of anorexia and bulimia and the outcome of presently used interventions. Everybody agrees that outcome must improve and to attack this clinical problem, we suggest a neurobiologically plausible framework for how the disorders develop and how they are maintained and outline a method of treatment and its results.

Animals↗
PubMed2003

What is the evidence basis for existing treatments of eating disorders?

Most existing treatments of eating disorders (ED) produce a period of remission that is short lived and expressed in fewer than 50% of the patients. Antidepressants (eg, selective serotonin reuptake inhibitors [SSRI]) have a small effect in bulimia nervosa and they are not recommended in anorexia nervosa (AN) because serotonin inhibits food intake. In a randomized, controlled trial, training of eating behavior and satiety, supply of warmth, reduction of physical hyperactivity, and restoration of social activities brought 75% of patients with ED into remission, and 93% remained in remission during follow-up. Further randomized, controlled trials comparing presently used interventions will provide the evidence needed to improve the treatment of ED.

Evidence-Based Medicine↗
PubMed2002

Randomized controlled trial of a treatment for anorexia and bulimia nervosa.

Evidence for the effectiveness of existing treatments of patients with eating disorders is weak. Here we describe and evaluate a method of treatment in a randomized controlled trial. Sixteen patients, randomly selected out of a group composed of 19 patients with anorexia nervosa and 13 with bulimia nervosa, were trained to eat and recognize satiety by using computer support. They rested in a warm room after eating, and their physical activity was restricted. The patients in the control group (n = 16) received no treatment. Remission was defined by normal body weight (anorexia), cessation of binge eating and purging (bulimia), a normal psychiatric profile, normal laboratory test values, normal eating behavior, and resumption of social activities. Fourteen patients went into remission after a median of 14.4 months (range 4.9-26.5) of treatment, but only one patient went into remission while waiting for treatment (P = 0.0057). Relapse is considered a major problem in patients who have been treated to remission. We therefore report results on a total of 168 patients who have entered our treatment program. The estimated rate of remission was 75%, and estimated time to remission was 14.7 months (quartile range 9.6 > or = 32). Six patients (7%) of 83 who were treated to remission relapsed, but the others (93%) have remained in remission for 12 months (quartile range 6-36). Because the risk of relapse is maximal in the first year after remission, we suggest that most patients treated with this method recover.

Adolescent↗
PubMed2002

Heat sterilization of peritoneal dialysis solutions influences ingestive behavior in non-uremic rats.

BACKGROUND: The appetite inhibitory effect of glucose-based peritoneal dialysis (PD) solutions may be due to glucose as such, or the hyperosmolality of the PD solution, or an effect of glucose degradation products (GDPs) formed in the PD solution during heat sterilization. This was studied in an experimental appetite model in rat. METHODS: The effect of different experimental PD solutions on ingestive behavior was investigated in non-uremic rats equipped with an implanted intraoral (i.o.) cannula through which a 1 mol/L sucrose solution was infused during tests. The amount of intake was recorded at 30 min after rats were infused intraperitoneally (IP) with 30 mL of different solutions. This method allowed an accurate and reproducible analysis of i.o. intake. The experimental PD solutions tested included (1) glucose based PD solutions with different glucose concentrations, sterilized by heat or microbiological filter, (2) glucose- and mannitol-based PD solutions with the same osmolality, sterilized by heat or microbiological filter; and (3) glucose based PD solutions, using different pH values (pH 3.0, pH 5.5 or pH 7.4) during heat sterilization. RESULTS: Following IP infusion of solutions, (1) the i.o. intake was significantly inhibited by glucose based, heat sterilized PD solutions and the degree of appetite suppression was related to the concentration of dialysate glucose in a dose-dependent way; (2) the i.o. intake was significantly less suppressed by filter sterilized than by heat sterilized glucose-based solutions; (3) the i.o. intake was significantly less following the IP infusion of glucose-based than following the mannitol-based heat sterilized solutions; however, i.o. intake did not differ between the glucose-based and mannitol-based filter sterilized solutions; and (4) furthermore, the degree of suppression of i.o. intake induced by glucose-based PD solutions was influenced by the pH value during heat sterilization. The lower the pH of the PD solution during heat sterilization, the higher the i.o. intake. CONCLUSIONS: The IP infusion of glucose-based heat-sterilized PD solutions inhibited food intake in this experimental appetite model, and the degree of suppression depended on the concentration of dialysate glucose and the pH of the solution during heat sterilization. The results suggest that GDPs formed during heat sterilization may exert a more adverse effect than glucose itself on ingestive behavior, and that a reduction of the concentration of GDPs in the PD solution using filter sterilization or a low pH value in the PD solution during heat sterilization may improve food intake.

Animals↗
PubMedDate not supplied

An innovative treatment programme for anorexia nervosa.

We present the case of an Australian girl with severe anorexia nervosa who had previously been resistant to treatment, and who was subsequently treated successfully by an innovative programme at the Karolinska Institute in Stockholm. The programme is based on a distinctive concept of causation of eating disorders in which it is postulated that they develop as a consequence of starvation rather than a primary mental disorder. The treatment focuses on relearning how to eat and perceive satiety using a unique feed-back system, together with provision of warmth, limitation of exercise and facilitating social adaptation.

Adolescent↗