No evidence that common genetic risk variation is shared between schizophrenia and autism

The similarity between aspects of the clinical presentation of schizophrenia and autism spectrum disorders (ASD) suggests that elements of the biological etiology may also be shared between these two disorders. Recently, an increasing number of rare, mostly structural genetic variants are reported to increase the risk of both schizophrenia and ASD. We hypothesized that given this evidence for a shared genetic background based on rare genetic variants, common risk alleles may also be shared between ASD and schizophrenia. To test this hypothesis, the polygenic score, which summarizes the collective effect of a large number of common risk alleles, was used. We examined whether the polygenic score derived from a schizophrenia case–control dataset, previously reported by Purcell et al., was able to differentiate ASD cases from controls. The results demonstrate that the schizophrenia‐derived polygenic score is not different between ASD cases and controls, indicating that there is no important sharing of common risk alleles between the two neuropsychiatric disorders. Possibly, common risk alleles are less important in ASD in comparison to their more prominent role in schizophrenia and bipolar disorders. These findings provide important novel insights into shared and distinct elements of the genetic architecture of autism and schizophrenia. © 2012 Wiley Periodicals, Inc.     

Endoscopic Duodenal–Jejunal Bypass Liner Rapidly Improves Type 2 Diabetes

Background

Bariatric procedures excluding the proximal small intestine improve glycemic control in type 2 diabetes within days. To gain insight into the mediators involved, we investigated factors regulating glucose homeostasis in patients with type 2 diabetes treated with the novel endoscopic duodenal–jejunal bypass liner (DJBL).

Methods

Seventeen obese patients (BMI 30–50 kg/m²) with type 2 diabetes received the DJBL for 24 weeks. Body weight and type 2 diabetes parameters, including HbA_1c and plasma levels of glucose, insulin, glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), and glucagon, were analyzed after a standard meal before, during, and 1 week after DJBL treatment.

Results

At 24 weeks after implantation, patients had lost 12.7?±?1.3 kg (p?<?0.01), while HbA_1c had improved from 8.4?±?0.2 to 7.0?±?0.2 % (p?<?0.01). Both fasting glucose levels and the postprandial glucose response were decreased at 1 week after implantation and remained decreased at 24 weeks (baseline vs. week 1 vs. week 24: 11.6?±?0.5 vs. 9.0?±?0.5 vs. 8.6?±?0.5 mmol/L and 1,999?±?85 vs. 1,536?±?51 vs. 1,538?±?72 mmol/L/min, both p?<?0.01). In parallel, the glucagon response decreased (23,762?±?4,732 vs. 15,989?±?3,193 vs. 13,1207?±?1,946 pg/mL/min, p?<?0.05) and the GLP-1 response increased (4,440?±?249 vs. 6,407?±?480 vs. 6,008?±?429 pmol/L/min, p?<?0.01). The GIP response was decreased at week 24 (baseline—115,272?±?10,971 vs. week 24—88,499?±?10,971 pg/mL/min, p?<?0.05). Insulin levels did not change significantly. Glycemic control was still improved 1 week after explantation.

Conclusions

The data indicate DJBL to be a promising treatment for obesity and type 2 diabetes, causing rapid improvement of glycemic control paralleled by changes in gut hormones.     

Dietetic intervention for inpatients on fluid‐only diets helps to achieve nutritional requirements

Aim

The present study aimed to assess whether dietetic intervention helps patients on fluid‐only diets to meet their energy and protein requirements. This topic has not been previously investigated.

Methods

A quasi‐experimental study of 57 patients receiving fluid‐only diets was conducted at The Townsville Hospital. The fluid consumption of participants was observed over 24 hours and was used to calculate total energy and protein intakes. The percentage of protein and energy requirements met was compared between patients receiving dietetic intervention and patients who were not.

Results

Patients receiving dietetic interventions met a higher percentage of their energy requirements (75.88) than the control group (18.10) based on median intakes (P < 0.001). Patients receiving dietetic intervention also met a higher percentage of their protein requirements (75.99) than the control group (13.80) based on median intakes (P < 0.001). Stratification for age, body mass index (BMI) and fluid diet type showed no change in effect.

Conclusions

This study shows that dietetic intervention enabled patients on fluid‐only diets to meet up to 80% more of their energy requirements and up to 95% more of their protein requirements. These results were consistent across age, BMI and fluid diet type. The significance of these differences has resulted in a change of clinical practice at the study hospital. All patients on fluid‐only diets for three days or longer are now blanket referred for dietetic intervention.