Bone Status in Obese, Non-diabetic, Antipsychotic-Treated Patients, and Effects of the Glucagon-Like Peptide-1 Receptor Agonist Exenatide on Bone Turnover Markers and Bone Mineral Density

Gut hormones and bone homeostasis: potential therapeutic implications

Bone resorption follows a circadian rhythm, with a marked reduction in circulating markers of resorption (such as carboxy-terminal telopeptide region of collagen type I in serum) in the postprandial period. Several gut hormones, including glucose-dependent insulinotropic polypeptide (GIP), glucagon-like peptide 1 (GLP1) and GLP2, have been linked to this effect in humans and rodent models. These hormones are secreted from enteroendocrine cells in the gastrointestinal tract in response to a variety of stimuli and effect a wide range of physiological processes within and outside the gut. Single GLP1, dual GLP1-GIP or GLP1-glucagon and triple GLP1-GIP-glucagon receptor agonists have been developed for the treatment of type 2 diabetes mellitus and obesity. In addition, single GIP, GLP1 and GLP2 analogues have been investigated in preclinical studies as novel therapeutics to improve bone strength in bone fragility disorders. Dual GIP-GLP2 analogues have been developed that show therapeutic promise for bone fragility in preclinical studies and seem to exert considerable activity at the bone material level. This Review summarizes the evidence of the action of gut hormones on bone homeostasis and physiology.

Effects of Incretin Therapy on Skeletal Health in Type 2 Diabetes-A Systematic Review

Diabetes poses a significant risk to bone health, with Type 1 diabetes (T1D) having a more detrimental impact than Type 2 diabetes (T2D). The group of hormones known as incretins, which includes gastric inhibitory peptide (GIP) and glucagon-like peptide 1 (GLP-1), play a role in regulating bowel function and insulin secretion during feeding. GLP-1 receptor agonists (GLP-1 RAs) are emerging as the primary treatment choice in T2D, particularly when atherosclerotic cardiovascular disease is present. Dipeptidyl peptidase 4 inhibitors (DPP-4is), although less potent than GLP-1 RAs, can also be used. Additionally, GLP-1 RAs, either alone or in combination with GIP, may be employed to address overweight and obesity. Since feeding influences bone turnover, a relationship has been established between incretins and bone health. To explore this relationship, we conducted a systematic literature review following the PRISMA guidelines. While some studies on cells and animals have suggested positive effects of incretins on bone cells, turnover, and bone density, human studies have yielded either no or limited and conflicting results regarding their impact on bone mineral density (BMD) and fracture risk. The effect on fracture risk may vary depending on the choice of comparison drug and the duration of follow-up, which was often limited in several studies. Nevertheless, GLP-1 RAs may hold promise for people with T2D who have multiple fracture risk factors and poor metabolic control. Furthermore, a potential new area of interest is the use of GLP-1 RAs in fracture prevention among overweight and obese people. Based on this systematic review, existing evidence remains insufficient to support a positive or a superior effect on bone health to reduce fracture risk in people with T2D. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Glucagon-like peptide-1 receptor-agonists treatment for cardio-metabolic parameters in schizophrenia patients: a systematic review and meta-analysis

Aims

We performed this meta-analysis to evaluate the efficacy and safety of glucagon-like peptide-1 receptor-agonists (GLP-1RA) treatment on cardio-metabolic parameters among antipsychotic-treated patients with schizophrenia.

Methods

We searched the Web of Science, Cochrane Central Register of Controlled Trials, PubMed, PsycINFO, and Scopus for relevant Randomized Clinical trials (RCTs) from inception until 1 August 2022. Documents were screened for qualified articles, and all concerned outcomes were pooled as risk ratios (RR) or mean difference (MD) in the meta-analysis models using Review Manager (RevMan version 5.4).

Results

Pooling data from 7 RCTs (398 patients) showed that GLP-1 RA was superior to placebo with regard to body weight [MD = - 4.68, 95% CI (-4.90,-4.46), P < 0.00001], waist circumference [MD = - 3.66, 95% CI (-3.89,-3.44), P < 0.00001], body mass index (BMI) [MD = - 1.09, 95% CI (-1.25,-0.93), P < 0.00001], systolic blood pressure (SBP) [MD = - 3.07, 95% CI (-3.61,-2.53), P < 0.00001], and diastolic blood pressure (DBP) [MD = - 2.02, 95% CI (-2.42,-1.62), P < 0.00001]. The total effect did not favor either of the two groups with respect to insulin and respiratory adverse events {[MD = - 0.06, 95% CI (-0.36, 0.24), p = 0.70], [RR = 0.66, 95% CI (0.31, 1.40), p = 0.28]; respectively}.

Conclusion

Our analysis revealed that GLP-1 RA treatment is safe and effective on cardio-metabolic parameters over control in antipsychotic-treated patients with schizophrenia. Nevertheless, the present evidence is not sufficient to confirm the safety and efficacy of GLP-1RA treatment on insulin and respiratory adverse events. Therefore, further studies are recommended.

Systematic review registration

http://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42022333040.

Relapse in patients with schizophrenia and amisulpride-induced hyperprolactinemia or olanzapine-induced metabolic disturbance after switching to other antipsychotics

Hyperprolactinemia and metabolic disturbance are common side effects of antipsychotics that cause intolerance. Despite its potential influence on relapse, there are no established guidelines for antipsychotic switching. This naturalistic study explored the association between antipsychotic switching, baseline clinical status, metabolic changes, and relapse in patients with schizophrenia. In total, 177 patients with amisulpride-induced hyperprolactinemia and 274 with olanzapine-induced metabolic disturbance were enrolled. Relapse was determined by assessing changes in Positive and Negative Syndrome Scale (PANSS) total scores from baseline to 6 months (increased over 20% or 10% reaching 70). Metabolic indices were measured at baseline and 3 months. Patients with baseline PANSS >60 were more likely to relapse. Further, patients switching to aripiprazole had a higher risk of relapse regardless of their original medication. Participants who originally used amisulpride had reduced prolactin levels following medication change, while switching to olanzapine caused increased weight and blood glucose levels. In patients originally using olanzapine, only switching to aripiprazole reduced insulin resistance. Adverse effects on weight and lipid metabolism were observed in patients who switched to risperidone, while amisulpride improved lipid profiles. Changing schizophrenia treatment requires careful consideration of multiple variables, particularly the choice of substituted drug and the patient's baseline symptoms.

Pharmacological interventions for prevention of weight gain in people with schizophrenia

BACKGROUND

Antipsychotic-induced weight gain is an extremely common problem in people with schizophrenia and is associated with increased morbidity and mortality. Adjunctive pharmacological interventions may be necessary to help manage antipsychotic-induced weight gain. This review splits and updates a previous Cochrane Review that focused on both pharmacological and behavioural approaches to this problem.

OBJECTIVES

To determine the effectiveness of pharmacological interventions for preventing antipsychotic-induced weight gain in people with schizophrenia.

SEARCH METHODS

The Cochrane Schizophrenia Information Specialist searched Cochrane Schizophrenia's Register of Trials on 10 February 2021. There are no language, date, document type, or publication status limitations for inclusion of records in the register.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) that examined any adjunctive pharmacological intervention for preventing weight gain in people with schizophrenia or schizophrenia-like illnesses who use antipsychotic medications.

DATA COLLECTION AND ANALYSIS

At least two review authors independently extracted data and assessed the quality of included studies. For continuous outcomes, we combined mean differences (MD) in endpoint and change data in the analysis. For dichotomous outcomes, we calculated risk ratios (RR). We assessed risk of bias for included studies and used GRADE to judge certainty of evidence and create summary of findings tables. The primary outcomes for this review were clinically important change in weight, clinically important change in body mass index (BMI), leaving the study early, compliance with treatment, and frequency of nausea. The included studies rarely reported these outcomes, so, post hoc, we added two new outcomes, average endpoint/change in weight and average endpoint/change in BMI.

MAIN RESULTS

Seventeen RCTs, with a total of 1388 participants, met the inclusion criteria for the review. Five studies investigated metformin, three topiramate, three H2 antagonists, three monoamine modulators, and one each investigated monoamine modulators plus betahistine, melatonin and samidorphan. The comparator in all studies was placebo or no treatment (i.e. standard care alone). We synthesised all studies in a quantitative meta-analysis. Most studies inadequately reported their methods of allocation concealment and blinding of participants and personnel. The resulting risk of bias and often small sample sizes limited the overall certainty of the evidence. Only one reboxetine study reported the primary outcome, number of participants with clinically important change in weight. Fewer people in the treatment condition experienced weight gains of more than 5% and more than 7% of their bodyweight than those in the placebo group (> 5% weight gain RR 0.27, 95% confidence interval (CI) 0.11 to 0.65; 1 study, 43 participants; > 7% weight gain RR 0.24, 95% CI 0.07 to 0.83; 1 study, 43 participants; very low-certainty evidence). No studies reported the primary outcomes, 'clinically important change in BMI', or 'compliance with treatment'. However, several studies reported 'average endpoint/change in body weight' or 'average endpoint/change in BMI'. Metformin may be effective in preventing weight gain (MD -4.03 kg, 95% CI -5.78 to -2.28; 4 studies, 131 participants; low-certainty evidence); and BMI increase (MD -1.63 kg/m2, 95% CI -2.96 to -0.29; 5 studies, 227 participants; low-certainty evidence). Other agents that may be slightly effective in preventing weight gain include H2 antagonists such as nizatidine, famotidine and ranitidine (MD -1.32 kg, 95% CI -2.09 to -0.56; 3 studies, 248 participants; low-certainty evidence) and monoamine modulators such as reboxetine and fluoxetine (weight: MD -1.89 kg, 95% CI -3.31 to -0.47; 3 studies, 103 participants; low-certainty evidence; BMI: MD -0.66 kg/m2, 95% CI -1.05 to -0.26; 3 studies, 103 participants; low-certainty evidence). Topiramate did not appear effective in preventing weight gain (MD -4.82 kg, 95% CI -9.99 to 0.35; 3 studies, 168 participants; very low-certainty evidence). For all agents, there was no difference between groups in terms of individuals leaving the study or reports of nausea. However, the results of these outcomes are uncertain given the very low-certainty evidence.

AUTHORS' CONCLUSIONS

There is low-certainty evidence to suggest that metformin may be effective in preventing weight gain. Interpretation of this result and those for other agents, is limited by the small number of studies, small sample size, and short study duration. In future, we need studies that are adequately powered and with longer treatment durations to further evaluate the efficacy and safety of interventions for managing weight gain.

A quinoxaline-based compound ameliorates bone loss in ovariectomized mice

DMB (6,7-dichloro-2-methylsulfonyl-3-Ntert-butylaminoquinoxaline) is a quinoxaline-based compound that has been investigated as a glucagon-like peptide-1 receptor (GLP-1R) agonist. To clarify anti-osteoporosis effect of DMB, an osteoporotic mice model was established by ovariectomy (OVX) operation. The OVX mice were given intraperitoneally DMB, exendin-4 (EX-4), or 17β-estradiol (E₂) for two months. Then bone mass and structure, and bone morphometric parameters were examined by micro-CT. Weight gain and food consumption, bone turnover markers, and biomechanical strength of the femur were tested, and bone histomorphometry was analyzed. The food intake and weight gain was obviously reduced by E₂ or EX-4, but not DMB. However, DMB or EX-4 treatment obviously inhibited skeletal deterioration and enhanced bone strength. The improvement involved in the increased osteoblast number and level of bone formation markers, and reduced osteoclasts number and level of bone resorption markers. In addition, DMB was found to stimulate osteoblastogenesis-related marker gene expression. These results demonstrated that DMB ameliorated bone loss mainly via induction of bone formation, which suggests that the small molecule compound might be applied to the management of postmenopausal osteoporosis.

Liraglutide does not change bone turnover in clozapine- and olanzapine-treated schizophrenia overweight patients with prediabetes - randomized controlled trial

Schizophrenia is associated with a lowered bone mineral density. The antidiabetic and body weight lowering glucagon-like peptide-1 receptor agonist liraglutide has shown to mitigate overweight and impaired glucose tolerance associated with olanzapine and clozapine. As liraglutide has been proposed to affect bone metabolism, we evaluated the effect of liraglutide on bone turnover markers (BTM) in patients with prediabetes and schizophrenia treated with olanzapine or clozapine. Patients diagnosed with a schizophrenia spectrum disorder treated with the antipsychotic compounds clozapine and/or olanzapine, having prediabetes and a BMI above 27 kg/m² were randomized to 16 weeks of treatment with liraglutide or placebo. Fasting state serum sampled in the morning from patients (n=78) were analysed for the BTM collagen type 1 C-telopeptide (CTX) and procollagen type 1 N-terminal propeptide (P1NP). After 16 weeks of treatment, no significant changes of neither P1NP nor CTX were observed when comparing liraglutide to placebo. No association between changes of bone turnover markers and change of body weight were found in the group treated with liraglutide. In conclusion, no treatment effect on CTX nor P1NP was observed, and thus, this study does not raise any concerns in patients with schizophrenia and prediabetes treated with liraglutide regarding bone-related adverse effects.

Association between bile acid metabolism and bone mineral density in postmenopausal women

OBJECTIVES

Previous studies have not shown any correlation between bile acid metabolism and bone mineral density (BMD) in women with postmenopausal osteoporosis. Thus, the current study evaluated the association between bile acid levels as well as BMD and bone turnover marker levels in this group of women.

METHODS

This single-center cross-sectional study included 150 postmenopausal Chinese women. According to BMD, the participants were divided into three groups: osteoporosis group, osteopenia group, and healthy control group. Serum bile acid, fibroblast growth factor 19 (FGF19), and bone turnover biomarker levels were assessed. Moreover, the concentrations of parathyroid hormone, 25-hydroxy vitamin D [25(OH)D], procollagen type I N-peptide (P1NP), and beta-CrossLaps of type I collagen containing cross-linked C-terminal telopeptide (β-CTX) were evaluated. The BMD of the lumbar spine and proximal femur were examined via dual-energy X-ray absorptiometry.

RESULTS

The serum total bile acid levels in the osteoporosis and osteopenia groups (5.28±1.56 and 5.31±1.56 umol/L, respectively) were significantly lower than that in the healthy control group (6.33±2.04 umol/L; p=0.002 and 0.018, respectively). Serum bile acid level was positively associated with the BMD of the lumbar spine, femoral neck, and total hip. However, it negatively correlated with β-CTX concentration. Moreover, no correlation was observed between bile acid and P1NP levels, and the levels of the other biomarkers that were measured did not differ between the groups.

CONCLUSION

Serum bile acid was positively correlated with BMD and negatively correlated with bone turnover biomarkers reflecting bone absorption in postmenopausal women. Thus, bile acid may play an important role in bone metabolism.

Glucagon-like peptide 1 (GLP-1)

BACKGROUND

The glucagon-like peptide-1 (GLP-1) is a multifaceted hormone with broad pharmacological potential. Among the numerous metabolic effects of GLP-1 are the glucose-dependent stimulation of insulin secretion, decrease of gastric emptying, inhibition of food intake, increase of natriuresis and diuresis, and modulation of rodent β-cell proliferation. GLP-1 also has cardio- and neuroprotective effects, decreases inflammation and apoptosis, and has implications for learning and memory, reward behavior, and palatability. Biochemically modified for enhanced potency and sustained action, GLP-1 receptor agonists are successfully in clinical use for the treatment of type-2 diabetes, and several GLP-1-based pharmacotherapies are in clinical evaluation for the treatment of obesity.

SCOPE OF REVIEW

In this review, we provide a detailed overview on the multifaceted nature of GLP-1 and its pharmacology and discuss its therapeutic implications on various diseases.

MAJOR CONCLUSIONS

Since its discovery, GLP-1 has emerged as a pleiotropic hormone with a myriad of metabolic functions that go well beyond its classical identification as an incretin hormone. The numerous beneficial effects of GLP-1 render this hormone an interesting candidate for the development of pharmacotherapies to treat obesity, diabetes, and neurodegenerative disorders.

Liraglutide suppresses TNF-α-induced degradation of extracellular matrix in human chondrocytes: a therapeutic implication in osteoarthritis

Osteoarthritis (OA) is a major global health problem; however, the etiology of the disease remains unknown and a reliable treatment strategy has yet to be discovered. Modulation of the receptor for glucagon-like peptide 1 (GLP-1) has emerged as a potential treatment strategy for various diseases including OA. In the present study, we investigated the effects of the specific GLP-1 receptor agonist liraglutide on factors of the pathogenesis of OA induced by tumor necrosis factor-α (TNF-α), including oxidative stress, expression of proinflammatory cytokines, degradation of articular cartilage extracellular matrix, and activation of the nuclear factor-κB (NF-κB) pathway. Our findings demonstrate that liraglutide exerted a potent beneficial effect in human primary chondrocytes by downregulating generation of reactive oxygen species and NADPH oxidase 4, suppressing expression of interleukin-6 and monocyte chemoattractant protein 1, rescuing type II collagen and aggrecan from degradation my matrix metalloproteinases and a disintegrin and metalloproteinase with type I thrombospondin motif, and inhibiting activation of the proinflammatory NF-κB signaling pathway. These findings demonstrate a potential role of GLP-1 receptor in the pathogenesis of OA and lay a foundation for further research on the mechanisms behind the potential therapeutic application of liraglutide in the treatment and prevention of OA.