Metformin Ameliorates Treatment of Obese Type 2 Diabetic Patients with Mental Retardation; its Effects on Eating Behavior and Serum Leptin Levels

Addressing Metabolic Comorbidity in Individuals With Intellectual and Developmental Disability on Antipsychotics: A Clinical Case Series

PURPOSE/BACKGROUND

Individuals with intellectual and developmental disabilities (IDDs) are at increased risk for serious metabolic comorbidities, which is further exacerbated by the high rate of antipsychotic use in this population. There is currently a lack of literature on effective treatment options for antipsychotic-induced weight gain and metabolic abnormalities in IDD. This case series reports on the clinical use of metformin in patients with IDD on antipsychotics.

METHODS/PROCEDURES

We conducted a retrospective review of patients in a novel clinical service at the Centre for Addiction and Mental Health in Toronto, Ontario, Canada for adults with IDD experiencing antipsychotic-related weight gain and other metabolic aberrations. Charts were reviewed for weight and other metabolic outcome measures before and after commencing metformin treatment.

FINDINGS/RESULTS

In 11 patients referred to this clinic, the mean weight loss while on metformin treatment was 11.1 kg, with over 50% of the sample achieving clinically meaningful weight loss of >7%. Additional adaptive changes were observed for fasting glucose, glycated hemoglobin, triglyceride, and high-density lipoprotein cholesterol levels.

IMPLICATIONS/CONCLUSIONS

In line with its use in severe mental illness, metformin may be a safe, effective, and accessible treatment option for patients with IDD experiencing metabolic adverse effects of antipsychotic medication. Further research and randomized controlled trials are needed to examine the efficacy of metformin in this population.

Dietary assessment of women surviving breast cancer according to the Dietary Guidelines for the Brazilian Population

ABSTRACT Objective Review the diet and nutritional status of women surviving breast cancer following the Dietary Guidelines for the Brazilian Population. Methods A cross-sectional study was conducted with 201 women, who underwent anthropometric measurements to determine body mass index, waist circumference and waist/hip ratio. Dietary assessment was performed usinga food frequency questionnaire. Consumption was stratifi ed into four groups: fresh/minimally processed food (Group 1), processed food ingredients (Group 2), processed food (Group 3) and ultra-processed food (Group 4).The ratio of daily contribution of each food group to total calories and macronutrients supply was calculated. Statistical analysis was performed using Chi-square tests and Spearman correlation, with p<0.05 as significance level. Results The mean age was 50 ± 11 years. An abdominal fat accumulation with a high excess weight condition in women under 60 years of age (p=0.003) was observed. A greater intake of group 1 food, but contributing with about 1/3 of the calories and macronutrients total intake as compared to food groups 3 and 4 was also observed. Conclusion The women assessed consumed a higher proportion of calories and macronutrients from fresh/minimally processed food. There is no theoretical reference that allows to affirm that the amount of processed andultra-processed food consumed represents a health hazard for those women. There was no association between dietary intake, nutritional status and age group.

Effects of metformin on weight loss: potential mechanisms

PURPOSE OF REVIEW

Despite the known glucose-lowering effects of metformin, more recent clinical interest lies in its potential as a weight loss drug. Herein, we discuss the potential mechanisms by which metformin decreases appetite and opposes unfavorable fat storage in peripheral tissues.

RECENT FINDINGS

Many individuals struggle to maintain clinically relevant weight loss from lifestyle and bariatric surgery interventions. Long-term follow-up from the Diabetes Prevention Program demonstrates that metformin produces durable weight loss, and decreased food intake by metformin is the primary weight loss mechanism. Although the effect of metformin on appetite is likely to be multifactorial, changes in hypothalamic physiology, including leptin and insulin sensitivity, have been documented. In addition, novel work in obesity highlights the gastrointestinal physiology and circadian rhythm changes by metformin as not only affecting food intake, but also the regulation of fat oxidation and storage in liver, skeletal muscle, and adipose tissue.

SUMMARY

Metformin induces modest weight loss in overweight and obese individuals at risk for diabetes. A more detailed understanding of how metformin induces weight loss will likely lead to optimal co-prescription of lifestyle modification with pharmacology for the treatment of obesity independent of diabetes.

Metformin inhibits food intake and neuropeptide Y gene expression in the hypothalamus

Metformin may reduce food intake and body weight, but the anorexigenic effects of metformin are still poorly understood. In this study, Sprague-Dawley rats were administered a single intracere-broventricular dose of metformin and compound C, in a broader attempt to investigate the regula-tory effects of metformin on food intake and to explore the possible mechanism. Results showed that central administration of metformin significantly reduced food intake and body weight gain, par-ticularly after 4 hours. A reduction of neuropeptide Y expression and induction of AMP-activated protein kinase phosphorylation in the hypothalamus were also observed 4 hours after metformin administration, which could be reversed by compound C, a commonly-used antagonist of AMP-activated protein kinase. Furthermore, metformin also improved lipid metabolism by reducing plasma low-density lipoprotein. Our findings suggest that under normal physiological conditions, central regulation of appetite by metformin is related to a decrease in neuropeptide Y gene expres-sion, and that the activation of AMP-activated protein kinase may simply be a response to the anorexigenic effect of metformin.

[D-Leu-4]-OB3, an orally bioavailable leptin-related synthetic peptide insulin sensitizer: a study comparing the efficacies of [D-Leu-4]-OB3 and metformin on energy balance and glycemic regulation in insulin-deficient male Swiss Webster mice

The effects of oral delivery of exenatide or pramlintide acetate in dodecyl maltoside (DDM) on energy balance and glycemic control in insulin-resistant obese db/db mice are enhanced when given in combination with [D-Leu-4]-OB3. To examine the anti-hyperglycemic influence of [D-Leu-4]-OB3 in a non-obese insulin-deficient animal model, we compared the effects of metformin (200mg/kg) and [D-Leu-4]-OB3 (40 mg/kg) on energy balance and glycemic control in streptozotocin (STZ)-induced diabetic male Swiss Webster (SW) mice. Diabetic mice were given insulin (Levemir(®), sc) alone, or in combination with metformin or [D-Leu-4]-OB3 orally in DDM, for 14 days. Body weight and food and water intake were measured daily. Fasting blood glucose levels were determined every other day. Serum C-peptide was measured by ELISA. Diabetic mice receiving insulin alone for 14 days gained significantly more weight than DDM-treated control mice, or mice given insulin in combination with metformin or [D-Leu-4]-OB3. The weight gain seen in mice given insulin alone was accompanied by significant increases in both food and water intake. Mice treated with insulin in combination with metformin or [D-Leu-4]-OB3, consumed significantly less food and water. Blood glucose levels in STZ-treated mice receiving insulin alone were reduced to 65.3% of initial levels, while mice receiving insulin with metformin or [D-Leu-4]-OB3 were reduced to 44.5% and 38.9%, respectively. Our results indicate that [D-Leu-4]-OB3 is as effective as metformin in preventing the body weight gain associated with insulin therapy, and on a molar basis, that the efficacy of [D-Leu-4]-OB3 as an insulin sensitizer may equal or surpass that of metformin.

The effect of metformin on food intake and its potential role in hypothalamic regulation in obese diabetic rats

Metformin appears to be involved in altering energy expenditure and thermogenesis, and could affect hypothalamic feeding circuits. However, it is not clear whether metformin is able to cross the blood-brain barrier (BBB) to reach the hypothalamus and exert a direct effect on the central nervous system. Here we show the presence of metformin in cerebrospinal fluid (CSF) of diabetic rats administered orally with metformin which was confirmed by detecting the concentration of metformin with liquid chromatography-tandem mass spectrometry. Food intake of diabetic rats treated with metformin was reduced, and glucose homeostasis was gained. Expression of orexigenic peptides neuropeptide Y (NPY) and agouti-related protein (AgRP) decreased in the hypothalamus of metformin-treated diabetic rats, though anorexigenic peptides pro-opiomelanocortin (POMC) did not change significantly. The phosphorylation of signal transducer and activator of transcription 3 (STAT3) was increased but phosphorylated AMP-activated kinase (AMPK) was similar in the hypothalamus of metformin-treated diabetic rats. Our findings suggest that metformin may cross BBB and play a central mechanism on regulation of food intake in the hypothalamus. The anorexic effect of metformin may be mediated by inhibition of NPY and AgRP gene expression through the STAT3 signaling pathway.

Nutrition and adults with intellectual or developmental disabilities: systematic literature review results

Approximately 4.5 million Americans have an intellectual or developmental disability. Concern is increasing about these individuals' nutrition-related behavior and its implications for their health. This article reports on a systematic search of the current literature listed in the PsycINFO and PubMed databases related to nutritional status of adults with intellectual or developmental disabilities. The authors used key terms for nutrition, secondary conditions, and intellectual and developmental disability and categorized literature pertaining to nutrition-related studies of adults with intellectual or developmental disabilities as follows: dietary intake studies, anthropometric assessments of nutritional risks, biochemical indexes, and clinical evaluations.

Metformin restores leptin sensitivity in high-fat-fed obese rats with leptin resistance

To evaluate whether metformin enhances leptin sensitivity, we measured leptin sensitivity after 4 weeks of metformin treatment (300 mg/kg daily) in both standard chow and high-fat-fed obese rats. Anorexic and fat-losing responses after intracerebroventricular leptin infusion for 7 days (15 microg daily per rat) in standard chow rats were enhanced by metformin treatment, and these responses to leptin were attenuated in high-fat-fed obese rats compared with age-matched standard chow rats. However, these responses to leptin were corrected by metformin treatment in high-fat-fed obese rats. Moreover, serum concentrations of leptin and insulin were decreased dramatically by leptin in metformin-treated standard chow and high-fat-fed obese rats. The hypothalamic phosphorylated AMP-activated protein kinase level was decreased by lower leptin dose in metformin-treated rats than in untreated rats. In an acute study, metformin treatment also increased the anorexic effect of leptin (5 microg), and this was accompanied by an increased level of phosphorylated signal transducer and activator of transcription 3 in the hypothalamus. These results suggest that metformin enhances leptin sensitivity and corrects leptin resistance in high-fat-fed obese rats and that a combination therapy including metformin and leptin would be helpful in the treatment of obesity.