Precision medicine for cardiometabolic disease: a framework for clinical translation

Cardiometabolic disease is a major threat to global health. Precision medicine has great potential to help to reduce the burden of this common and complex disease cluster, and to enhance contemporary evidence-based medicine. Its key pillars are diagnostics; prediction (of the primary disease); prevention (of the primary disease); prognosis (prediction of complications of the primary disease); treatment (of the primary disease or its complications); and monitoring (of risk exposure, treatment response, and disease progression or remission). To contextualise precision medicine in both research and clinical settings, and to encourage the successful translation of discovery science into clinical practice, in this Series paper we outline a model (the EPPOS model) that builds on contemporary evidence-based approaches; includes precision medicine that improves disease-related predictions by stratifying a cohort into subgroups of similar characteristics, or using participants' characteristics to model treatment outcomes directly; includes personalised medicine with the use of a person's data to objectively gauge the efficacy, safety, and tolerability of therapeutics; and subjectively tailors medical decisions to the individual's preferences, circumstances, and capabilities. Precision medicine requires a well functioning system comprised of multiple stakeholders, including health-care recipients, health-care providers, scientists, health economists, funders, innovators of medicines and technologies, regulators, and policy makers. Powerful computing infrastructures supporting appropriate analysis of large-scale, well curated, and accessible health databases that contain high-quality, multidimensional, time-series data will be required; so too will prospective cohort studies in diverse populations designed to generate novel hypotheses, and clinical trials designed to test them. Here, we carefully consider these topics and describe a framework for the integration of precision medicine in cardiometabolic disease.

Use of Real-World Data in Population Science to Improve the Prevention and Care of Diabetes-Related Outcomes

The past decade of population research for diabetes has seen a dramatic proliferation of the use of real-world data (RWD) and real-world evidence (RWE) generation from non-research settings, including both health and non-health sources, to influence decisions related to optimal diabetes care. A common attribute of these new data is that they were not collected for research purposes yet have the potential to enrich the information around the characteristics of individuals, risk factors, interventions, and health effects. This has expanded the role of subdisciplines like comparative effectiveness research and precision medicine, new quasi-experimental study designs, new research platforms like distributed data networks, and new analytic approaches for clinical prediction of prognosis or treatment response. The result of these developments is a greater potential to progress diabetes treatment and prevention through the increasing range of populations, interventions, outcomes, and settings that can be efficiently examined. However, this proliferation also carries an increased threat of bias and misleading findings. The level of evidence that may be derived from RWD is ultimately a function of the data quality and the rigorous application of study design and analysis. This report reviews the current landscape and applications of RWD in clinical effectiveness and population health research for diabetes and summarizes opportunities and best practices in the conduct, reporting, and dissemination of RWD to optimize its value and limit its drawbacks.

Consensus report: Definition and interpretation of remission in type 2 diabetes

Improvement of glucose levels into the normal range can occur in some people living with diabetes, either spontaneously or after medical interventions, and in some cases can persist after withdrawal of glucose-lowering pharmacotherapy. Such sustained improvement may now be occurring more often due to newer forms of treatment. However, terminology for describing this process and objective measures for defining it are not well established, and the long-term risks versus benefits of its attainment are not well understood. To update prior discussions of this issue, an international expert group was convened by the American Diabetes Association to propose nomenclature and principles for data collection and analysis, with the goal of establishing a base of information to support future clinical guidance. This group proposed "remission" as the most appropriate descriptive term, and HbA1c <6.5% (48 mmol/mol) measured at least 3 months after cessation of glucose-lowering pharmacotherapy as the usual diagnostic criterion. The group also made suggestions for active observation of individuals experiencing a remission and discussed further questions and unmet needs regarding predictors and outcomes of remission.

Heterogeneity of Diabetes: β-Cells, Phenotypes, and Precision Medicine: Proceedings of an International Symposium of the Canadian Institutes of Health Research's Institute of Nutrition, Metabolism and Diabetes and the U.S. National Institutes of Health's National Institute of Diabetes and Digestive and Kidney Diseases

One hundred years have passed since the discovery of insulin-an achievement that transformed diabetes from a fatal illness into a manageable chronic condition. The decades since that momentous achievement have brought ever more rapid innovation and advancement in diabetes research and clinical care. To celebrate the important work of the past century and help to chart a course for its continuation into the next, the Canadian Institutes of Health Research's Institute of Nutrition, Metabolism and Diabetes and the U.S. National Institutes of Health's National Institute of Diabetes and Digestive and Kidney Diseases recently held a joint international symposium, bringing together a cohort of researchers with diverse interests and backgrounds from both countries and beyond to discuss their collective quest to better understand the heterogeneity of diabetes and thus gain insights to inform new directions in diabetes treatment and prevention. This article summarizes the proceedings of that symposium, which spanned cutting-edge research into various aspects of islet biology, the heterogeneity of diabetic phenotypes, and the current state of and future prospects for precision medicine in diabetes.

Consensus Report: Definition and Interpretation of Remission in Type 2 Diabetes

Improvement of glucose levels into the normal range can occur in some people living with diabetes, either spontaneously or after medical interventions, and in some cases can persist after withdrawal of glucose-lowering pharmacotherapy. Such sustained improvement may now be occurring more often due to newer forms of treatment. However, terminology for describing this process and objective measures for defining it are not well established, and the long-term risks versus benefits of its attainment are not well understood. To update prior discussions of this issue, an international expert group was convened by the American Diabetes Association to propose nomenclature and principles for data collection and analysis, with the goal of establishing a base of information to support future clinical guidance. This group proposed "remission" as the most appropriate descriptive term, and HbA1c < 6.5% (48 mmol/mol) measured at least 3 months after cessation of glucose-lowering pharmacotherapy as the usual diagnostic criterion. The group also made suggestions for active observation of individuals experiencing a remission and discussed further questions and unmet needs regarding predictors and outcomes of remission.

Heterogeneity of Diabetes: β-Cells, Phenotypes, and Precision Medicine: Proceedings of an International Symposium of the Canadian Institutes of Health Research's Institute of Nutrition, Metabolism and Diabetes and the U.S. National Institutes of Health's National Institute of Diabetes and Digestive and Kidney Diseases

One hundred years have passed since the discovery of insulin-an achievement that transformed diabetes from a fatal illness into a manageable chronic condition. The decades since that momentous achievement have brought ever more rapid innovation and advancement in diabetes research and clinical care. To celebrate the important work of the past century and help to chart a course for its continuation into the next, the Canadian Institutes of Health Research's Institute of Nutrition, Metabolism and Diabetes and the U.S. National Institutes of Health's National Institute of Diabetes and Digestive and Kidney Diseases recently held a joint international symposium, bringing together a cohort of researchers with diverse interests and backgrounds from both countries and beyond to discuss their collective quest to better understand the heterogeneity of diabetes and thus gain insights to inform new directions in diabetes treatment and prevention. This article summarizes the proceedings of that symposium, which spanned cutting-edge research into various aspects of islet biology, the heterogeneity of diabetic phenotypes, and the current state of and future prospects for precision medicine in diabetes.

Heterogeneity of Diabetes: β-Cells, Phenotypes, and Precision Medicine: Proceedings of an International Symposium of the Canadian Institutes of Health Research's Institute of Nutrition, Metabolism and Diabetes and the U.S. National Institutes of Health's National Institute of Diabetes and Digestive and Kidney Diseases

One hundred years have passed since the discovery of insulin-an achievement that transformed diabetes from a fatal illness into a manageable chronic condition. The decades since that momentous achievement have brought ever more rapid innovation and advancement in diabetes research and clinical care. To celebrate the important work of the past century and help to chart a course for its continuation into the next, the Canadian Institutes of Health Research's Institute of Nutrition, Metabolism and Diabetes and the U.S. National Institutes of Health's National Institute of Diabetes and Digestive and Kidney Diseases recently held a joint international symposium, bringing together a cohort of researchers with diverse interests and backgrounds from both countries and beyond to discuss their collective quest to better understand the heterogeneity of diabetes and thus gain insights to inform new directions in diabetes treatment and prevention. This article summarizes the proceedings of that symposium, which spanned cutting-edge research into various aspects of islet biology, the heterogeneity of diabetic phenotypes, and the current state of and future prospects for precision medicine in diabetes.

Consensus report: definition and interpretation of remission in type 2 diabetes

Improvement of glucose levels into the normal range can occur in some people living with diabetes, either spontaneously or after medical interventions, and in some cases can persist after withdrawal of glucose-lowering pharmacotherapy. Such sustained improvement may now be occurring more often due to newer forms of treatment. However, terminology for describing this process and objective measures for defining it are not well established, and the long-term risks vs benefits of its attainment are not well understood. To update prior discussions of this issue, an international expert group was convened by the American Diabetes Association to propose nomenclature and principles for data collection and analysis, with the goal of establishing a base of information to support future clinical guidance. This group proposed 'remission' as the most appropriate descriptive term, and HbA_1c <48 mmol/mol (6.5%) measured at least 3 months after cessation of glucose-lowering pharmacotherapy as the usual diagnostic criterion. The group also made suggestions for active observation of individuals experiencing a remission and discussed further questions and unmet needs regarding predictors and outcomes of remission.

Consensus Report: Definition and Interpretation of Remission in Type 2 Diabetes

Improvement of glucose levels into the normal range can occur in some people living with diabetes, either spontaneously or after medical interventions, and in some cases can persist after withdrawal of glucose-lowering pharmacotherapy. Such sustained improvement may now be occurring more often due to newer forms of treatment. However, terminology for describing this process and objective measures for defining it are not well established, and the long-term risks versus benefits of its attainment are not well understood. To update prior discussions of this issue, an international expert group was convened by the American Diabetes Association to propose nomenclature and principles for data collection and analysis, with the goal of establishing a base of information to support future clinical guidance. This group proposed "remission" as the most appropriate descriptive term, and HbA1c <6.5% (48 mmol/mol) measured at least 3 months after cessation of glucose-lowering pharmacotherapy as the usual diagnostic criterion. The group also made suggestions for active observation of individuals experiencing a remission and discussed further questions and unmet needs regarding predictors and outcomes of remission.

COVID-19 and metabolic diseases: a heightened awareness of health inequities and a renewed focus for research priorities

Chronic metabolic disorders such as diabetes and obesity are major public health issues in the United States. However, significant disparities in their prevalence and incidence place a greater burden on US racial and ethnic minority groups, contributing to worse COVID-19 outcomes in many. Improving treatment and prevention of diabetes and obesity is critical to the NIDDK. In this Perspective, we will review the burden of metabolic diseases in the United States, the observed disparities for metabolic diseases in relation to COVID-19, and research opportunities to address underlying causes of metabolic diseases, their associated health disparities, and COVID-19.

Precision medicine in diabetes: a Consensus Report from the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD)

The convergence of advances in medical science, human biology, data science and technology has enabled the generation of new insights into the phenotype known as 'diabetes'. Increased knowledge of this condition has emerged from populations around the world, illuminating the differences in how diabetes presents, its variable prevalence and how best practice in treatment varies between populations. In parallel, focus has been placed on the development of tools for the application of precision medicine to numerous conditions. This Consensus Report presents the American Diabetes Association (ADA) Precision Medicine in Diabetes Initiative in partnership with the European Association for the Study of Diabetes (EASD), including its mission, the current state of the field and prospects for the future. Expert opinions are presented on areas of precision diagnostics and precision therapeutics (including prevention and treatment) and key barriers to and opportunities for implementation of precision diabetes medicine, with better care and outcomes around the globe, are highlighted. Cases where precision diagnosis is already feasible and effective (i.e. monogenic forms of diabetes) are presented, while the major hurdles to the global implementation of precision diagnosis of complex forms of diabetes are discussed. The situation is similar for precision therapeutics, in which the appropriate therapy will often change over time owing to the manner in which diabetes evolves within individual patients. This Consensus Report describes a foundation for precision diabetes medicine, while highlighting what remains to be done to realise its potential. This, combined with a subsequent, detailed evidence-based review (due 2022), will provide a roadmap for precision medicine in diabetes that helps improve the quality of life for all those with diabetes.

Precision Medicine in Diabetes: A Consensus Report From the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD)

The convergence of advances in medical science, human biology, data science, and technology has enabled the generation of new insights into the phenotype known as "diabetes." Increased knowledge of this condition has emerged from populations around the world, illuminating the differences in how diabetes presents, its variable prevalence, and how best practice in treatment varies between populations. In parallel, focus has been placed on the development of tools for the application of precision medicine to numerous conditions. This Consensus Report presents the American Diabetes Association (ADA) Precision Medicine in Diabetes Initiative in partnership with the European Association for the Study of Diabetes (EASD), including its mission, the current state of the field, and prospects for the future. Expert opinions are presented on areas of precision diagnostics and precision therapeutics (including prevention and treatment), and key barriers to and opportunities for implementation of precision diabetes medicine, with better care and outcomes around the globe, are highlighted. Cases where precision diagnosis is already feasible and effective (i.e., monogenic forms of diabetes) are presented, while the major hurdles to the global implementation of precision diagnosis of complex forms of diabetes are discussed. The situation is similar for precision therapeutics, in which the appropriate therapy will often change over time owing to the manner in which diabetes evolves within individual patients. This Consensus Report describes a foundation for precision diabetes medicine, while highlighting what remains to be done to realize its potential. This, combined with a subsequent, detailed evidence-based review (due 2022), will provide a roadmap for precision medicine in diabetes that helps improve the quality of life for all those with diabetes.

Clinical Targets for Continuous Glucose Monitoring Data Interpretation: Recommendations From the International Consensus on Time in Range

Improvements in sensor accuracy, greater convenience and ease of use, and expanding reimbursement have led to growing adoption of continuous glucose monitoring (CGM). However, successful utilization of CGM technology in routine clinical practice remains relatively low. This may be due in part to the lack of clear and agreed-upon glycemic targets that both diabetes teams and people with diabetes can work toward. Although unified recommendations for use of key CGM metrics have been established in three separate peer-reviewed articles, formal adoption by diabetes professional organizations and guidance in the practical application of these metrics in clinical practice have been lacking. In February 2019, the Advanced Technologies & Treatments for Diabetes (ATTD) Congress convened an international panel of physicians, researchers, and individuals with diabetes who are expert in CGM technologies to address this issue. This article summarizes the ATTD consensus recommendations for relevant aspects of CGM data utilization and reporting among the various diabetes populations.

Clinical Targets for Continuous Glucose Monitoring Data Interpretation: Recommendations From the International Consensus on Time in Range

Improvements in sensor accuracy, greater convenience and ease of use, and expanding reimbursement have led to growing adoption of continuous glucose monitoring (CGM). However, successful utilization of CGM technology in routine clinical practice remains relatively low. This may be due in part to the lack of clear and agreed-upon glycemic targets that both diabetes teams and people with diabetes can work toward. Although unified recommendations for use of key CGM metrics have been established in three separate peer-reviewed articles, formal adoption by diabetes professional organizations and guidance in the practical application of these metrics in clinical practice have been lacking. In February 2019, the Advanced Technologies & Treatments for Diabetes (ATTD) Congress convened an international panel of physicians, researchers, and individuals with diabetes who are expert in CGM technologies to address this issue. This article summarizes the ATTD consensus recommendations for relevant aspects of CGM data utilization and reporting among the various diabetes populations.

Diabetes Care Editors' Expert Forum 2018: Managing Big Data for Diabetes Research and Care

Technological progress in the past half century has greatly increased our ability to collect, store, and transmit vast quantities of information, giving rise to the term "big data." This term refers to very large data sets that can be analyzed to identify patterns, trends, and associations. In medicine-including diabetes care and research-big data come from three main sources: electronic medical records (EMRs), surveys and registries, and randomized controlled trials (RCTs). These systems have evolved in different ways, each with strengths and limitations. EMRs continuously accumulate information about patients and make it readily accessible but are limited by missing data or data that are not quality assured. Because EMRs vary in structure and management, comparisons of data between health systems may be difficult. Registries and surveys provide data that are consistently collected and representative of broad populations but are limited in scope and may be updated only intermittently. RCT databases excel in the specificity, completeness, and accuracy of their data, but rarely include a fully representative sample of the general population. Also, they are costly to build and seldom maintained after a trial's end. To consider these issues, and the challenges and opportunities they present, the editors of Diabetes Care convened a group of experts in management of diabetes-related data on 21 June 2018, in conjunction with the American Diabetes Association's 78th Scientific Sessions in Orlando, FL. This article summarizes the discussion and conclusions of that forum, offering a vision of benefits that might be realized from prospectively designed and unified data-management systems to support the collective needs of clinical, surveillance, and research activities related to diabetes.

Glucose Management Indicator (GMI): A New Term for Estimating A1C From Continuous Glucose Monitoring

While A1C is well established as an important risk marker for diabetes complications, with the increasing use of continuous glucose monitoring (CGM) to help facilitate safe and effective diabetes management, it is important to understand how CGM metrics, such as mean glucose, and A1C correlate. Estimated A1C (eA1C) is a measure converting the mean glucose from CGM or self-monitored blood glucose readings, using a formula derived from glucose readings from a population of individuals, into an estimate of a simultaneously measured laboratory A1C. Many patients and clinicians find the eA1C to be a helpful educational tool, but others are often confused or even frustrated if the eA1C and laboratory-measured A1C do not agree. In the U.S., the Food and Drug Administration determined that the nomenclature of eA1C needed to change. This led the authors to work toward a multipart solution to facilitate the retention of such a metric, which includes renaming the eA1C the glucose management indicator (GMI) and generating a new formula for converting CGM-derived mean glucose to GMI based on recent clinical trials using the most accurate CGM systems available. The final aspect of ensuring a smooth transition from the old eA1C to the new GMI is providing new CGM analyses and explanations to further understand how to interpret GMI and use it most effectively in clinical practice. This Perspective will address why a new name for eA1C was needed, why GMI was selected as the new name, how GMI is calculated, and how to understand and explain GMI if one chooses to use GMI as a tool in diabetes education or management.

Potential adverse effects of botanical supplementation in high-fat-fed female mice

BACKGROUND

Insulin resistance underlies metabolic syndrome and is associated with excess adiposity and visceral fat accumulation, which is more frequently observed in males than females. However, in young females, the prevalence of metabolic syndrome is rising, mainly driven by accumulation of abdominal visceral fat. The degree to which sex-related differences could influence the development of insulin resistance remains unclear, and studies of potential therapeutic strategies to combat metabolic syndrome using rodent models have focused predominantly on males. We therefore evaluated the effects of two nutritional supplements derived from botanical sources, an extract of Artemisia dracunculus L. (termed PMI5011) and Momordica charantia (commonly known as bitter melon), on female mice challenged with a high-fat diet in order to determine if dietary intake of these supplements could ameliorate obesity-induced insulin resistance and metabolic inflexibility in skeletal muscle.

METHODS

Body composition, physical activity and energy expenditure, fatty acid oxidation, insulin signaling, and gene and protein expression of factors controlling lipid metabolism and ectopic lipid accumulation were evaluated in female mice fed a high-fat diet supplemented with either PMI5011 or bitter melon. Statistical significance was assessed by unpaired two-tailed t test and repeated measures ANOVA.

RESULTS

PMI5011 supplementation resulted in increased body weight and adiposity, while bitter melon did not induce changes in these parameters. Pyruvate tolerance testing indicated that both supplements increased hepatic glucose production. Both supplements induced a significant suppression in fatty acid oxidation in skeletal muscle homogenates treated with pyruvate, indicating enhanced metabolic flexibility. PMI5011 reduced lipid accumulation in skeletal muscle, while bitter melon induced a downward trend in lipid accumulation in the skeletal muscle and liver. This was accompanied by transcriptional regulation of autophagic genes by bitter melon in the liver.

CONCLUSIONS

Data from the current study indicates that dietary supplementation with PMI5011 and bitter melon evokes a divergent, and generally less favorable, set of metabolic responses in female mice compared to effects previously observed in males. Our findings underscore the importance of considering sex-related variations in responses to dietary supplementation aimed at combating metabolic syndrome.

Early Time-Restricted Feeding Improves Insulin Sensitivity, Blood Pressure, and Oxidative Stress Even without Weight Loss in Men with Prediabetes

Intermittent fasting (IF) improves cardiometabolic health; however, it is unknown whether these effects are due solely to weight loss. We conducted the first supervised controlled feeding trial to test whether IF has benefits independent of weight loss by feeding participants enough food to maintain their weight. Our proof-of-concept study also constitutes the first trial of early time-restricted feeding (eTRF), a form of IF that involves eating early in the day to be in alignment with circadian rhythms in metabolism. Men with prediabetes were randomized to eTRF (6-hr feeding period, with dinner before 3 p.m.) or a control schedule (12-hr feeding period) for 5 weeks and later crossed over to the other schedule. eTRF improved insulin sensitivity, β cell responsiveness, blood pressure, oxidative stress, and appetite. We demonstrate for the first time in humans that eTRF improves some aspects of cardiometabolic health and that IF's effects are not solely due to weight loss.

Skeletal muscle ceramides and daily fat oxidation in obesity and diabetes

BACKGROUND/OBJECTIVES

Ectopic accumulation of lipids in skeletal muscle and the formation of deleterious lipid intermediates is thought to contribute to the development of insulin resistance and type 2 diabetes mellitus (T2DM). Similarly, impaired fat oxidation (metabolic inflexibility) are predictors of weight gain and the development of T2DM; however, no study has investigated the relation between muscle ceramide accumulation and 24-hour macronutrient oxidation. The purpose of this study was to retrospectively explore the relationships between whole body fat oxidation and skeletal muscle ceramide accumulation in obese non-diabetic individuals (ND) and in people with obesity and T2DM.

METHODS

Daily substrate oxidation was measured in a respiratory chamber and skeletal muscle ceramides were measured using liquid chromatographyelectrospray ionization tandem-mass spectrometry.

RESULTS

After adjusting for sex, age, and BMI, no differences existed between the groups for fat oxidation or 24-h RQ. However, ceramides C18:1, C:20, C22, C24 and C24:1 were significantly higher in people with T2DM compared to ND whereas no differences existed for C16 and C18. Despite low amounts of muscle ceramides, fat oxidation rates were positively associated with ceramide species concentration in ND only. Our data suggests that ceramides do not interfere with whole-body fat oxidation in ND individuals whereas a persistent lipid oversupply results in excessive ceramide muscle accumulation in people with T2DM.

An Extract of Russian Tarragon Prevents Obesity-Related Ectopic Lipid Accumulation

SCOPE

The primary disorder underlying metabolic syndrome is insulin resistance due to excess body weight and abdominal visceral fat accumulation. In this study, it is asked if dietary intake of an ethanolic extract from Russian tarragon (Artemisia dracunculus L., termed PMI5011), shown to improve glucose utilization by enhancing insulin signaling in skeletal muscle, could prevent obesity-induced insulin resistance, skeletal muscle metabolic inflexibility, and ectopic lipid accumulation in the skeletal muscle and liver.

METHODS AND RESULTS

Male wild-type mice are fed a high-fat diet alone or supplemented with PMI5011 (1% w/w) over 3 months. Dietary intake of PMI5011 improved fatty acid oxidation and metabolic flexibility in the skeletal muscle, reduced insulin levels, and enhanced insulin signaling in the skeletal muscle and liver independent of robust changes in expression of factors that control fatty acid oxidation. This corresponds with significantly reduced lipid accumulation in the skeletal muscle and liver, although body weight gain is comparable to a high-fat diet alone.

CONCLUSION

Previous studies showed that PMI5011 enhances insulin sensitivity in the setting of established obesity-induced insulin resistance. The current study demonstrates that dietary intake of PMI5011 prevents high-fat diet-induced insulin resistance, metabolic dysfunction, and ectopic lipid accumulation in the skeletal muscle and liver without reducing body weight.

Cardiovascular Outcomes Trials in Type 2 Diabetes: Where Do We Go From Here? Reflections From a Diabetes Care Editors' Expert Forum

In December 2008, the U.S. Food and Drug Administration issued guidance to the pharmaceutical industry setting new expectations for the development of antidiabetes drugs for type 2 diabetes. This guidance expanded the scope and cost of research necessary for approval of such drugs by mandating long-term cardiovascular outcomes trials (CVOTs) for safety. Since 2008, 9 CVOTs have been reported, 13 are under way, and 4 have been terminated. Reassuringly, each of the completed trials demonstrated the noninferiority of their respective drugs to placebo for their primary cardiovascular (CV) composite end point. Notably, four additionally provided evidence of CV benefit in the form of significant decreases in the primary CV composite end point, two suggested reductions in CV death, and three suggested reductions in all-cause mortality. Although these trials have yielded much valuable information, whether that information justifies the investment of time and resources is controversial. In June 2016, a Diabetes Care Editors' Expert Forum convened to review the processes and challenges of CVOTs, discuss the benefits and limitations of their current designs, and weigh the merits of modifications that might improve the efficiency and clinical value of future trials. Discussion and analysis continued with the CVOT trial results released in June 2017 at the American Diabetes Association's Scientific Sessions and in September 2017 at the European Association for the Study of Diabetes scientific meeting. This article summarizes the discussion and findings to date.

Creatine ( methyl-d3) dilution in urine for estimation of total body skeletal muscle mass: accuracy and variability vs. MRI and DXA

A noninvasive method to estimate muscle mass based on creatine ( methyl-d₃) (D₃-creatine) dilution using fasting morning urine was evaluated for accuracy and variability over a 3- to 4-mo period. Healthy older (67- to 80-yr-old) subjects ( n = 14) with muscle wasting secondary to aging and four patients with chronic disease (58-76 yr old) fasted overnight and then received an oral 30-mg dose of D₃-creatine at 8 AM ( day 1). Urine was collected during 4 h of continued fasting and then at consecutive 4- to 8-h intervals through day 5. Assessment was repeated 3-4 mo later in 13 healthy subjects and 1 patient with congestive heart failure. Deuterated and unlabeled creatine and creatinine were measured using liquid chromatography-tandem mass spectrometry. Total body creatine pool size and muscle mass were calculated from D₃-creatinine enrichment in urine. Muscle mass was also measured by whole body MRI and 24-h urine creatinine, and lean body mass (LBM) was measured by dual-energy X-ray absorptiometry (DXA). D₃-creatinine urinary enrichment from day 5 provided muscle mass estimates that correlated with MRI for all subjects ( r = 0.88, P < 0.0001), with less bias [difference from MRI = -3.00 ± 2.75 (SD) kg] than total LBM assessment by DXA, which overestimated muscle mass vs. MRI (+22.5 ± 3.7 kg). However, intraindividual variability was high with the D₃-creatine dilution method, with intrasubject SD for estimated muscle mass of 2.5 kg vs. MRI (0.5 kg) and DXA (0.8 kg). This study supports further clinical validation of the D₃-creatine method for estimating muscle mass. NEW & NOTEWORTHY Measurement of creatine ( methyl-d₃) (D₃-creatine) and D₃-creatinine excretion in fasted morning urine samples may be a simple, less costly alternative to MRI or dual-energy X-ray absorptiometry (DXA) to calculate total body muscle mass. The D₃-creatine enrichment method provides estimates of muscle mass that correlate well with MRI, and with less bias than DXA. However, intraindividual variability is high with the D₃-creatine method. Studies to refine the spot urine sample method for estimation of muscle mass may be warranted.

An update on sodium-glucose co-transporter-2 inhibitors for the treatment of diabetes mellitus

PURPOSE OF REVIEW

Sodium-glucose co-transporter-2 (SGLT2) inhibitors are the newest class of oral antihyperglycemic agents that have been approved for the treatment of diabetes mellitus. Over the past year, there have been significant developments in both the safety and efficacy of this class of medications that are presented in this review.

RECENT FINDINGS

Apart from data on the glucose-lowering effect of SGLT2 inhibitors, other metabolic benefits have been demonstrated for this class of medications. Moreover, there have been three Food and Drug Administration Drug Safety Communications issued in 2015 that have led to additional drug labeling. The basic mechanism of action, indications, glucose-lowering benefits, other metabolic benefits, and adverse side-effects of SGLT2 inhibitors are presented in this review.

SUMMARY

SGLT2 inhibitors are medications that have a unique mechanism of action and that lower glucose independent of insulin. Given the recent findings on efficacy and benefits, these agents are rapidly establishing their role in the treatment of diabetes. Especially in patients with type 2 diabetes not willing or not ready to start insulin, SGLT2 inhibitors may be another option in those patients requiring additional glucose lowering and in those with acceptable risk factor profiles. Although there appears to be some positive benefits in cardiovascular endpoints, more research on the long-term outcomes in people taking SGLT2 inhibitors is warranted.

"Prediabetes": Are There Problems With This Label? No, We Need Heightened Awareness of This Condition!

The category of "prediabetes" defined by the American Diabetes Association comprises a range of intermediate hyperglycemia based on fasting or 2-h postload glucose or on HbA1c Over the recent past, the "cut points" identifying this stage have changed, i.e., a lower fasting glucose level is used. On one hand, it can be argued that the change to a lower cut point identifies a group of individuals still at higher risk and provides heightened awareness for a condition associated with higher risk for cardiovascular disease. In addition, identification of individuals at this stage may represent a chance of earlier intervention in the disease. However, the argument against this definition of prediabetes is that it disguises the differences in the three subcategories and creates problems in interpreting observations on interventions and outcomes. In addition, it can be argued that the enormous numbers of people identified with the criteria far exceeds the capacity of health care systems to respond through individual care, particularly without evidence that interventions benefit any category other than impaired glucose tolerance. Thus, there does not appear to be consensus on the definition using the cut points identified. Controversy also remains as to whether there are glycemic metrics beyond HbA1c that can be used in addition to HbA1c to help assess risk of an individual developing diabetes complications. Given the current controversy, a Point-Counterpoint debate on this issue is provided herein. In the preceding point narrative, Dr. Yudkin provides his argument that there are significant problems with this label. In the counterpoint narrative below, Dr. Cefalu argues that the cut points are appropriate and do provide useful and important information in trying to reduce the future burden of diabetes.-William T. CefaluEditor in Chief, Diabetes Care.