Reduction of Depression in Diabetes: A New Pleiotropic Action of Metformin?

Metformin and fibromyalgia pathophysiology: current insights and promising future therapeutic strategies

Fibromyalgia (FM) is a complex, chronic pain syndrome characterized by widespread musculoskeletal pain, fatigue, and cognitive disturbances. Despite its prevalence, the pathophysiology of FM remains poorly understood, with current treatments often providing limited relief. Recent studies have suggested that metformin, a widely used antidiabetic drug, may have potential therapeutic benefits for chronic pain conditions, including FM. This review aims to provide current insights into the role of metformin in FM pathophysiology, focusing on its neurotransmitter-modulating and anti-inflammatory effects. Metformin has been shown to mitigate neuroinflammation, protect neural tissues, and modulate key neurotransmitters involved in pain and mood regulation. These effects are particularly evident in animal models, where metformin has been observed to reduce pain sensitivity, improve mood-related behaviors, and decrease levels of pro-inflammatory cytokines like interleukin 1-beta (IL-1β). Additionally, the ability of metformin to influence serotonin, norepinephrine, and glutamate levels suggests a potential mechanism for its analgesic and mood-stabilizing effects. However, the current evidence is largely preclinical, and further research is needed to confirm these findings in human studies. This review aims to encourage researchers to explore the association between metformin and FM more deeply, with the hope of uncovering new therapeutic strategies that could offer relief to FM patients.

The Antinociceptive Effects and Sex-Specific Neurotransmitter Modulation of Metformin in a Mouse Model of Fibromyalgia

Fibromyalgia (FM) is a chronic and debilitating condition characterized by diffuse pain, often associated with symptoms such as fatigue, cognitive disturbances, and mood disorders. Metformin, an oral hypoglycemic agent, has recently gained attention for its potential benefits beyond glucose regulation. It has shown promise in alleviating neuropathic and inflammatory pain, suggesting that it could offer a novel approach to managing chronic pain conditions like FM. This study aimed to further explore metformin's analgesic potential by evaluating its effects in an experimental FM model induced by reserpine in both male and female mice. After the administration of 200 mg/kg metformin to male and female mice, the FM-related symptoms were assessed, including mechanical allodynia, thermal hyperalgesia, and depressive-like behaviors. A histological examination of the thalamus, hippocampus, and spinal cord was conducted using haematoxylin and eosin staining. The neurotransmitter and proinflammatory cytokines levels were measured in the brains and spinal cords. Our results have shown that metformin treatment for seven days significantly reversed these FM-like symptoms, reducing pain sensitivity and improving mood-related behaviors in both the male and female mice. Additionally, metformin exhibited neuroprotective effects, mitigating reserpine-induced damage in the hippocampus, thalamus, and spinal cord. It also significantly lowered the levels of the proinflammatory cytokine interleukin 1-beta (IL-1β) in the brain and spinal cord. Notably, metformin modulated the neurotransmitter levels differently between the sexes, decreasing glutamate and increasing serotonin and norepinephrine in the male mice, but not in the females. These findings underscore metformin's potential as an alternative therapy for FM, with sex-specific differences suggesting distinct mechanisms of action.

Metformin in Type 2 Diabetes: Evidence for its Beneficial Effects on Frailty and Sarcopenia

This narrative review aimed to discuss the potential interplay among frailty syndrome, sarcopenia and metformin in type 2 diabetes mellitus (T2DM). There is emerging evidence on the potential protective role of metformin on both frailty and sarcopenia. However, results are not always consistent. Thus, further research is needed to provide a definitive answer on any role of metformin in improving frailty and/or sarcopenia in T2DM.

Τhe Endless Beauty of Metformin: Does It Also Protect from Skin Aging? A Narrative Review

Metformin has shown multiple effects beyond its widely known antidiabetic effect. Impressively, it has already been proposed as an anti-aging factor. However, the potentially protective role of metformin in skin aging, the most common manifestation of aging, is not well examined. Existing evidence based on experimental studies suggests a potential anti-aging effect on skin. Proposed molecular skin anti-aging mechanisms of metformin include mainly reduction of nuclear factor kappa B (NF-κB) (p65) activity. Moreover, metformin appears to inhibit ultraviolet B (UVB)-induced secretion of pro-inflammatory cytokines. Nonetheless, data is still limited, and so more studies are needed. Importantly, we need more studies conducted in humans to further examine this interesting potential. Until then, whether oral administration of metformin or local use of the agent could be used to delay skin aging remains to be answered.

Association of metformin and depression in patients with type 2 diabetes

BACKGROUND

Emerging evidence showed metformin may have pleiotropic effects on ameliorating depression. However, whether metformin was associated with decreased risk of depression remains unclear.

METHODS

A historical cohort study was conducted based on a medical claim database from 2010 to 2017 in Beijing, China. Patients newly diagnosed with T2D were classified into the metformin and non-metformin groups according to their initial antidiabetic prescription. The incidences of depression between the groups were compared using Cox proportional regression model.

RESULTS

There were 193,624 (37.4 %) and 323,930 (62.6 %) T2D patients in the metformin and non-metformin groups. The mean age was 54.9 (SD: 13.1) years and 53.9% were females. With a median follow-up of 3.2 years, 64,963 patients developed depression. The adjusted incidence of depression in the metformin group (30.6, 95 % CI: 30.1, 31.0 per 1000 person-years) was significantly lower than in the non-metformin group (39.6, 95 % CI: 39.3, 40.0 per 1000 person-years, P < 0.001). The metformin group was significantly associated with a lower risk of depression compared with the overall non-metformin group (HR: 0.77, 95% CI: 0.75, 0.78), as well as compared with α-glucosidase inhibitors (HR: 0.73, 95 % CI: 0.71, 0.74), sulfonylureas (HR: 0.84, 95 % CI: 0.82, 0.86), and glinides (HR: 0.85, 95 % CI: 0.82, 0.88), except for thiazolidinediones (HR: 0.96, 95 % CI: 0.91, 1.01). The association between metformin and lower depression risk was significant in all the age and sex subgroups.

CONCLUSIONS

Metformin was associated with a lower risk of depression compared with other oral hypoglycemic agents, indicating a potential pleiotropic effect on depression.

Drug-drug interactions involving combinations of antipsychotic agents with antidiabetic, lipid-lowering, and weight loss drugs

INTRODUCTION

Patients with severe mental illness (SMI) have a high risk for diabetes, dyslipidemia, and other components of metabolic syndrome. Patients with these metabolic comorbidities and cardiac risk factors should receive not only antipsychotics but also medications aiming to reduce cardiovascular risk. Therefore, many patients may be exposed to clinically relevant drug-drug interactions.

AREAS COVERED

This narrative review summarizes data regarding the known or potential drug-drug interactions between antipsychotics and medications treating metabolic syndrome components, except for hypertension, which has been summarized elsewhere. A literature search in PubMed and Scopus up to 7/31/2021 was performed regarding interactions between antipsychotics and drugs used to treat metabolic syndrome components, aiming to inform clinicians' choice of medication for patients with SMI and cardiometabolic risk factors in need of pharmacologic interventions.

EXPERT OPINION

The cytochrome P450 system and, to a lesser extent, the P-glycoprotein transporter is involved in the pharmacokinetic interactions between antipsychotics and some statins or saxagliptin. Regarding pharmacodynamic interactions, the available information is based mostly on small studies, and for newer classes, like PCSK9 inhibitors or SGLT2 inhibitors, data are still lacking. However, there is sufficient information to guide clinicians in the process of selecting safer antipsychotic-cardiometabolic risk reduction drug combinations.

An association between multi-morbidity and depressive symptoms among Indian adults based on propensity score matching

Keeping in view the cascade of disturbances caused by the co-existence of multi-morbidity and depression among aged population, this study aims to ascertain the independent impact of multi-morbidity as a risk factor for the development of depressive symptoms among adults living in India. The present study utilizes data from the nationally representative survey “Longitudinal Ageing Study in India” (LASI, Wave-1, 2017–2018). The eligible sample size was 62,244 adults aged 45 years and above. Descriptive statistics along with bivariate analysis was used to understand the prevalence of depressive symptoms. Further, binary logistic regression and Propensity Score Matching (PSM) methods were applied to examine the independent effect of multi-morbidity on depressive symptoms while controlling the selected background characteristics. Overall, around one-third respondents had at least one chronic disease and one-fifth had multi-morbidity. The most prevalent chronic disease reported in the sampled population was hypertension followed by diabetes and joint disease. It is observed that older adults with multiple chronic diseases had 77% higher odds of having depressive symptoms as compared to those without a history of chronic disease in the multivariable logistic regression model. Results obtained from PSM indicate that the risk of having depressive symptoms was 3.7% higher for adults with multi- morbidity. Depressive symptom was identified to be associated with a wider range of multiple physical health problems and people with multi-morbidity are at a higher risk of having depressive symptoms. It is imperative that multi-morbidity can be used as a screener for identifying people with depressive symptoms.

Reduced Progression of Monoclonal Gammopathy of Undetermined Significance to Multiple Myeloma in Type 2 Diabetes Mellitus: Will Metformin Never Stop Its Pleasant Surprises?

Monoclonal gammopathy of undetermined significance (MGUS) is an asymptomatic plasma cell disorder characterised by a serum M protein level below 3 g/dL, percentage of bone marrow clonal plasma cells below 10%, absence of end-organ damage (hypercalcaemia, renal insufficiency, anaemia, bone lesions) and absence of any other disease known to produce M protein. MGUS may progress to myeloproliferative disorders or multiple myeloma, but very little is known about any modifiable risk factors or any preventative treatment that might delay this progression. Metformin has begun to be discussed as a potentially useful agent on the basis of the results of epidemiological and preclinical research showing that it may be beneficial in patients with leukaemia, lymphomas and multiple myeloma. Metformin studies dedicated to MGUS are currently very limited, yet it would appear that there may be hope for reducing progression of MGUS to multiple myeloma with metformin in type 2 diabetes mellitus. However, more data is needed until we reach a clearer view of what is to be gained with metformin in this setting.