Metformin's effectiveness in preventing prednisone-induced hyperglycemia in hematological cancers

Treatment of glucocorticoid- induced hyperglycemia in hospitalized patients - a systematic review and meta- analysis

PURPOSE

Glucocorticoid (GC)-induced hyperglycemia is a frequent issue, however there are no specific guidelines for this diabetes subtype. Although treat-to-target insulin is recommended in general to correct hyperglycemia, it remains unclear which treatment strategy has a positive effect on outcomes. We performed a systematic review and meta-analysis of randomized controlled trials (RCTs) to assess whether treating GC-induced hyperglycemia improves clinical outcomes.

METHODS

MEDLINE and EMBASE were systematically searched for RCTs on adults reporting treatment and outcomes of GC-induced hyperglycemia since the beginning of the data bases until October 21, 2023. Glucose-lowering strategies as compared to usual care were investigated.

RESULTS

We found 17 RCTs with 808 patients and included seven trials in the quantitative analysis. Patients with an intensive glucose-lowering strategy had lower standardized mean glucose levels of - 0.29 mmol/l (95%CI -0.64 to -0.05) compared to usual care group patients. There was no increase in hypoglycemic events in the intensively treated groups (RR 0.91, 95%CI 0.70-1.17). Overall, we did not have enough trials reporting clinical outcomes for a quantitative analysis with only one trial reporting mortality.

CONCLUSION

In GC-induced hyperglycemia, tight glucose control has a moderate effect on mean glucose levels with no apparent harmful effect regarding hypoglycemia. There is insufficient data whether insulin treatment improves clinical outcomes, and data on non-insulin based treatment regimens are currently too sparse to draw any conclusions.

SYSTEMATIC REVIEW REGISTRATION

Registered as CRD42020147409 at PROSPERO ( https://www.crd.york.ac.uk/prospero/ ) on April 28, 2020.

Glucocorticoid-Induced Hyperglycemia Including Dexamethasone-Associated Hyperglycemia in COVID-19 Infection: A Systematic Review

OBJECTIVE

Optimal glucocorticoid-induced hyperglycemia (GCIH) management is unclear. The COVID-19 pandemic has made this issue more prominent because dexamethasone became the standard of care in patients needing respiratory support. This systematic review aimed to describe the management of GCIH and summarize available management strategies for dexamethasone-associated hyperglycemia in patients with COVID-19.

METHODS

A systematic review was conducted using the PubMed/MEDLINE, Cochrane Library, Embase, and Web of Science databases with results from 2011 through January 2022. Keywords included synonyms for "steroid-induced diabetes" or "steroid-induced hyperglycemia." Randomized controlled trials (RCTs) were included for review of GCIH management. All studies focusing on dexamethasone-associated hyperglycemia in COVID-19 were included regardless of study quality.

RESULTS

Initial search for non-COVID GCIH identified 1230 references. After screening and review, 33 articles were included in the non-COVID section of this systematic review. Initial search for COVID-19-related management of dexamethasone-associated hyperglycemia in COVID-19 identified 63 references, whereas 7 of these were included in the COVID-19 section. RCTs of management strategies were scarce, did not use standard definitions for hyperglycemia, evaluated a variety of treatment strategies with varying primary end points, and were generally not found to be effective except for Neutral Protamine Hagedorn insulin added to basal-bolus regimens.

CONCLUSION

Few RCTs are available evaluating GCIH management. Further studies are needed to support the formulation of clinical guidelines for GCIH especially given the widespread use of dexamethasone during the COVID-19 pandemic.

The effect of metformin on glucose metabolism in patients receiving glucocorticoids

Glucocorticoids have powerful anti-inflammatory and immunomodulatory effects, but chronic use of these drugs can cause hyperglycemia, type 2 diabetes mellitus, hepatic steatosis, obesity, and other complications due to their metabolic actions. Metformin is a widely used drug for the treatment of type 2 diabetes mellitus with a known ability to lower blood glucose levels. This review focuses on metformin's actions on glucose metabolism and its potential use as a drug to limit the metabolic side effects of glucocorticoid treatment. Available data suggest that metformin inhibits complex I of the mitochondrial electron transport chain, crucial gluconeogenic enzymes, and fatty acid synthesis that leads to a significant improvement in glucose tolerance and maintenance of insulin sensitivity during glucocorticoid treatment. Three small randomized control trials have demonstrated that metformin can limit changes in glucose metabolism during treatment with prednisone. These studies reveal a promising potential for metformin use as a therapeutic agent to reduce glucocorticoid-induced hyperglycemia and improve patient outcomes.

Fresh insights into glucocorticoid-induced diabetes mellitus and new therapeutic directions

Glucocorticoid hormones were discovered to have use as potent anti-inflammatory and immunosuppressive therapeutics in the 1940s and their continued use and development have successfully revolutionized the management of acute and chronic inflammatory diseases. However, long-term use of glucocorticoids is severely hampered by undesirable metabolic complications, including the development of type 2 diabetes mellitus. These effects occur due to glucocorticoid receptor activation within multiple tissues, which results in inter-organ crosstalk that increases hepatic glucose production and inhibits peripheral glucose uptake. Despite the high prevalence of glucocorticoid-induced hyperglycaemia associated with their routine clinical use, treatment protocols for optimal management of the metabolic adverse effects are lacking or underutilized. The type, dose and potency of the glucocorticoid administered dictates the choice of hypoglycaemic intervention (non-insulin or insulin therapy) that should be provided to patients. The longstanding quest to identify dissociated glucocorticoid receptor agonists to separate the hyperglycaemic complications of glucocorticoids from their therapeutically beneficial anti-inflammatory effects is ongoing, with selective glucocorticoid receptor modulators in clinical testing. Promising areas of preclinical research include new mechanisms to disrupt glucocorticoid signalling in a tissue-selective manner and the identification of novel targets that can selectively dissociate the effects of glucocorticoids. These research arms share the ultimate goal of achieving the anti-inflammatory actions of glucocorticoids without the metabolic consequences.

Glucocorticoid-Induced Hyperglycemia in Oncologic Outpatients: A Narrative Review Using the Quadruple Aim Framework

Glucocorticoids are a central part of cancer treatment protocols. Their use in patients receiving chemotherapy increases patient risk of hyperglycemia and associated adverse outcomes. Despite this, there have been few published protocols that guide the management of this patient group. In this narrative review, we use the quadruple aim as a framework to evaluate the current literature, including interventions, on glucocorticoid-induced hyperglycemia in patients receiving oncologic treatment, with a focus on the outpatient setting. Findings were drawn from published review articles, observational studies, qualitative reports and costing data. Results were synthesized using the framework's 4 dimensions of care: population health, provider experience, patient experience and cost. Prospective studies proposing an intervention on oncologic patients receiving glucocorticoids were identified as intervention studies. Management of glucocorticoid-induced hyperglycemia in oncologic patients is a complex problem with no published interventions addressing all components of the quadruple aim. Most evidence on this population is based on retrospective studies. Six prospective intervention studies were identified and highlighted in this review, and only 2 were exclusively in the outpatient context. Challenges included lack of standardization in screening strategies, paucity of interventions that have examined impact on patient and provider experience. There is limited evaluation of the impact of interventions targeting glycemic control on clinical outcomes and cost of care delivery, especially in the outpatient context. We propose a conceptual framework for evaluation of quality improvement programs. Management of glucocorticoid-induced hyperglycemia in the outpatient setting is complex and requires well-designed intervention studies evaluated across the quadruple aim.

Current cancer therapies and their influence on glucose control

This review focuses on the development of hyperglycemia arising from widely used cancer therapies spanning four drug classes. These groups of medications were selected due to their significant association with new onset hyperglycemia, or of potentially severe clinical consequences when present. These classes include glucocorticoids that are frequently used in addition to chemotherapy treatments, and the antimetabolite class of 5-fluorouracil-related drugs. Both of these classes have been in use in cancer therapy since the 1950s. Also considered are the phosphatidyl inositol-3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR)-inhibitors that provide cancer response advantages by disrupting cell growth, proliferation and survival signaling pathways, and have been in clinical use as early as 2007. The final class to be reviewed are the monoclonal antibodies selected to function as immune checkpoint inhibitors (ICIs). These were first used in 2011 for advanced melanoma and are rapidly becoming widely utilized in many solid tumors. For each drug class, the literature has been reviewed to answer relevant questions about these medications related specifically to the characteristics of the hyperglycemia that develops with use. The incidence of new glucose elevations in euglycemic individuals, as well as glycemic changes in those with established diabetes has been considered, as has the expected onset of hyperglycemia from their first use. This comparison emphasizes that some classes exhibit very immediate impacts on glucose levels, whereas other classes can have lengthy delays of up to 1 year. A comparison of the spectrum of severity of hyperglycemic consequences stresses that the appearance of diabetic ketoacidosis is rare for all classes except for the ICIs. There are distinct differences in the reversibility of glucose elevations after treatment is stopped, as the mTOR inhibitors and ICI classes have persistent hyperglycemia long term. These four highlighted drug categories differ in their underlying mechanisms driving hyperglycemia, with clinical presentations ranging from potent yet transient insulin resistant states [type 2 diabetes mellitus (T2DM) -like] to rare permanent insulin-deficient causes of hyperglycemia. Knowledge of the relative incidence of new onset hyperglycemia and the underlying causes are critical to appreciate how and when to best screen and treat patients taking any of these cancer drug therapies.

How should rheumatologists manage glucocorticoid-induced hyperglycemia?

Glucocorticoid-induced hyperglycemia (GIH) is an important complication to be managed by rheumatologists as it can affect morbidity and mortality of patients. Before administration of glucocorticoids, risk for the development of GIH should be assessed in every patient. A meta-analysis identified male gender, older age, family history of diabetes mellitus, current smoking history, past history of hypertension, higher body mass index, higher fasting plasma glucose (PG) and higher hemoglobin A1c (HbA1c) levels as risk factors for GIH. Then, rheumatologists need to carefully monitored PG levels including 2-h after meals because glucocorticoids particularly affect postprandial glucose metabolism. Fasting PG level ≥ 126 mg/dL and/or post-meal PG level ≥ 200 mg/dL are considered as GIH regardless of HbA1c level. Treatment strategy for GIH should center on insulin injection since the effectiveness of oral hypoglycemic agents for GIH has been uncertain. But, rheumatologists may try oral hypoglycemic agents in advance of insulin therapy for mild GIH, whereas diabetologists should be consulted in case of intractable GIH. More strict control of GIH could be possible using intensive insulin protocol. Rheumatologists are encouraged to be interested in the management of GIH for providing patients superior care, working closely with diabetologists.