No effect of dietary fat on short-term weight gain in mice treated with atypical antipsychotic drugs

Assessment of the Effects of Dietary Vitamin D Levels on Olanzapine-Induced Metabolic Side Effects: Focus on the Endocannabinoidome-Gut Microbiome Axis

Vitamin D deficiency is associated with poor mental health and dysmetabolism. Several metabolic abnormalities are associated with psychotic diseases, which can be compounded by atypical antipsychotics that induce weight gain and insulin resistance. These side-effects may be affected by vitamin D levels. The gut microbiota and endocannabinoidome (eCBome) are significant regulators of both metabolism and mental health, but their role in the development of atypical antipsychotic drug metabolic side-effects and their interaction with vitamin D status is unknown. We studied the effects of different combinations of vitamin D levels and atypical antipsychotic drug (olanzapine) exposure on whole-body metabolism and the eCBome-gut microbiota axis in female C57BL/6J mice under a high fat/high sucrose (HFHS) diet in an attempt to identify a link between the latter and the different metabolic outputs induced by the treatments. Olanzapine exerted a protective effect against diet-induced obesity and insulin resistance, largely independent of dietary vitamin D status. These changes were concomitant with olanzapine-mediated decreases in Trpv1 expression and increases in the levels of its agonists, including various N-acylethanolamines and 2-monoacylglycerols, which are consistent with the observed improvement in adiposity and metabolic status. Furthermore, while global gut bacteria community architecture was not altered by olanzapine, we identified changes in the relative abundances of various commensal bacterial families. Taken together, changes of eCBome and gut microbiota families under our experimental conditions might contribute to olanzapine and vitamin D-mediated inhibition of weight gain in mice on a HFHS diet.

Olanzapine leads to nonalcoholic fatty liver disease through the apolipoprotein A5 pathway

The antipsychotic drug olanzapine was reported to induce nonalcoholic fatty liver disease (NAFLD), whereas the underlying mechanism remains incompletely understood. This study investigated whether apolipoprotein A5 (apoA5) and sortilin, two interactive factors involved in NAFLD pathogenesis, are implicated in olanzapine-induced NAFLD. In our study, at week 8, olanzapine treatment successfully induced hepatic steatosis in female C57 BL/6 J mice, which was independent of body weight gain. Likewise, olanzapine effectively mediated hepatocyte steatosis in HepG2 cells characterized by substantially elevated intracellular lipid droplets. Increased plasma triglyceride concentration and decreased plasma apoA5 levels were observed in mice treated with 8-week olanzapine. Surprisingly, olanzapine markedly enhanced hepatic apoA5 protein levels in mice, without a significant effect on rodent hepatic ApoA5 mRNA. Our in vitro study showed that olanzapine reduced apoA5 protein levels in the medium and enhanced apoA5 protein levels in hepatocytes, whereas this drug exerted no effect on hepatocyte APOA5 mRNA. By transfecting APOA5 siRNA into HepG2 cells, it was demonstrated that APOA5 knockdown effectively reversed olanzapine-induced hepatocyte steatosis in vitro. In addition, olanzapine drastically increased sortilin mRNA and protein levels in vivo and in vitro. Interestingly, SORT1 knockdown reduced intracellular apoA5 protein levels and increased medium apoA5 protein levels in vitro, without affecting intracellular APOA5 mRNA levels. Furthermore, SORT1 knockdown greatly ameliorated hepatocyte steatosis in vitro. This study provides the first evidence that sortilin inhibits the hepatic apoA5 secretion that is attributable to olanzapine-induced NAFLD, which provides new insight into effective strategies against NAFLD for patients with schizophrenia administered olanzapine.

Diet and cardiometabolic side effects in children treated with second-generation antipsychotics

BACKGROUND

Second-generation antipsychotic (SGA) treatment in children is associated with metabolic side effects including weight gain, dyslipidemia, and insulin resistance. The objective of this study is to determine if SGA treatment in children affects dietary intakes and relationship to metabolic side effects.

METHODS

Three-day food records assessed dietary energy and macronutrient intakes in a cross-sectional population of SGA-treated (n = 35) and SGA-naïve (n = 29) children.

RESULTS

SGA-treated children had more overweight/obesity (BMI ≥ 85th percentile for age and sex, p = 0.001); waist circumference (WC) ≥ 90th percentile for age and sex (p = 0.007); waist:height ratio (WHtR) ≥ 85th percentile for age and sex (p = 0.004), greater HOMA-IR, (p = 0.001) and plasma triglycerides (p = 0.017), and lower plasma HDL (p = 0.029). Dietary energy intakes were not different between SGA-naïve and SGA-treated children [1734 ± 486 vs 1971 ± 649 (-135, 408) kcal/day, mean ± SD (95% CI)] after adjustments for sex, age, Tanner stage, psychostimulant use, and height. Similarly, no differences in macronutrient intakes were observed. In models adjusted for SGA treatment and physical activity, no relationships between dietary intakes and BMI were found, but dietary total energy intakes were positively associated with waist circumference z-scores (p = 0.019), systolic blood pressure z-scores (p = 0.028, also adjusted for BMI) and HOMA-IR (p = 0.013, also adjusted for age, sex, BMI). All of the children had poor diets with 87.5% having >7% of daily energy from saturated fat; 62.5% having >20% of daily energy from sugar; and almost 60% having sodium intakes above the tolerable upper intake level.

CONCLUSIONS

SGA treatment is not associated with greater dietary energy intakes in children. However, dietary energy intakes are associated with greater waist circumference and systolic blood pressure z-scores and HOMA-IR in children with mental health conditions.

Atypical antipsychotics and effects on feeding: from mice to men

RATIONALE

So-called atypical antipsychotics (AAPs) are associated with varying levels of weight gain and associated metabolic disturbances, which in patients with serious mental illness (SMI) have been linked to non-compliance and poor functional outcomes. Mechanisms underlying AAP-induced metabolic abnormalities are only partially understood. Antipsychotic-induced weight gain may occur as a result of increases in food intake and/or changes in feeding.

OBJECTIVE

In this review, we examine the available human and preclinical literature addressing AAP-related changes in feeding behavior, to determine whether changes in appetite and perturbations in regulation of food intake could be contributing factors to antipsychotic-induced weight gain.

RESULTS

In general, human studies point to disruption by AAPs of feeding behaviors and food consumption. In rodents, increases in cumulative food intake are mainly observed in females; however, changes in feeding microstructure or motivational aspects of food intake appear to occur independent of sex.

CONCLUSIONS

The findings from this review indicate that the varying levels of AAP-related weight gain reflect changes in both appetite and feeding behaviors, which differ by type of AAP. However, inconsistencies exist among the studies (both human and rodent) that may reflect considerable differences in study design and methodology. Future studies examining underlying mechanisms of antipsychotic-induced weight gain are recommended in order to develop strategies addressing the serious metabolic side effect of AAPs.

Effects of risperidone on energy balance in female C57BL/6J mice

OBJECTIVE

To investigate the effect of risperidone on energy expenditure and weight gain in female C57BL/6J mice.

DESIGN AND METHODS

Body weight and composition, food intake, energy expenditure, and activity were determined weekly. mRNA expression of uncoupling protein 1 in brown adipose tissue, orexin, and brain-derived neurotrophic factor in the hypothalamus were quantified using real-time PCR.

RESULTS

Risperidone tended to induce a greater body weight gain (P = 0.052) and significantly higher food intake (P = 0.038) relative to the placebo-treated group. Risperidone-treated mice had a higher resting energy expenditure (P = 0.001) and total energy expenditure (TEE) (P = 0.005) than the placebo group. There were no effects of treatment, time, and treatment by time on non-resting (or activity-related) energy expenditure between groups. Risperidone-treated mice showed a significantly lesser locomotor activity than placebo-treated mice over 3 weeks (P < 0.001). Risperidone induced a higher UCP1 mRNA (P = 0.003) and a lower orexin mRNA (P = 0.001) than placebo.

CONCLUSION

Risperidone-induced weight gain is associated with hyperphagia and a reduction in locomotor activity in C57BL/6J mice. Additionally, higher total and resting energy expenditure were accompanied by higher levels of UCP1 mRNA in BAT. The increased TEE could not offset the total intake of energy through risperidone-induced hyperphagia, therefore resulting in weight gain in female C57BL/6J mice.