Contemporary trends in the utilization of second-line pharmacological therapies for type 2 diabetes in the United States and the United Kingdom

AIM

To examine trends of second-line glucose-lowering therapies among patients with type 2 diabetes (T2D) initiating first-line metformin in the United States and the United Kingdom, overall and by subgroups of cardiovascular disease (CVD) and calendar time.

METHODS

Using the US Optum Clinformatics and the UK Clinical Practice Research Datalink, we identified adults with T2D who initiated first-line metformin or sulphonylurea monotherapy, separately, from 2013 to 2019. Within both cohorts, we identified patterns of second-line medications through June 2021. We stratified patterns by CVD and calendar time to investigate the impact of rapidly evolving treatment guidelines.

RESULTS

We identified 148 511 and 169 316 patients initiating treatment with metformin monotherapy in the United States and the United Kingdom, respectively. Throughout the study period, sulphonylureas and dipeptidyl peptidase-4 inhibitors were the most frequently initiated second-line medications in the United States (43.4% and 18.2%, respectively) and the United Kingdom (42.5% and 35.8%, respectively). After 2018, sodium-glucose co-transporter 2 inhibitors and glucagon-like peptide-1 receptor agonists were more commonly used as second-line agents in the United States and the United Kingdom, although these agents were not preferentially prescribed among patients with CVD. Initiation of first-line sulphonylureas was much less common, and most sulphonylurea initiators had metformin added as the second-line agent.

CONCLUSIONS

This international cohort study shows that sulphonylureas remain the most common second-line medications prescribed following metformin in both the United States and the United Kingdom. Despite recommendations, the use of newer glucose-lowering therapies with cardiovascular benefits remains low.

Bi-Directional Interactions between Glucose-Lowering Medications and Gut Microbiome in Patients with Type 2 Diabetes Mellitus: A Systematic Review

Background: Although common drugs for treating type 2 diabetes (T2D) are widely used, their therapeutic effects vary greatly. The interaction between the gut microbiome and glucose-lowering drugs is one of the main contributors to the variability in T2D progression and response to therapy. On the one hand, glucose-lowering drugs can alter gut microbiome components. On the other hand, specific gut microbiota can influence glycemic control as the therapeutic effects of these drugs. Therefore, this systematic review assesses the bi-directional relationships between common glucose-lowering drugs and gut microbiome profiles. Methods: A systematic search of Embase, Web of Science, PubMed, and Google Scholar databases was performed. Observational studies and randomised controlled trials (RCTs), published from inception to July 2023, comprising T2D patients and investigating bi-directional interactions between glucose-lowering drugs and gut microbiome, were included. Results: Summarised findings indicated that glucose-lowering drugs could increase metabolic-healthy promoting taxa (e.g., Bifidobacterium) and decrease harmful taxa (e.g., Bacteroides and Intestinibacter). Our findings also showed a significantly different abundance of gut microbiome taxa (e.g., Enterococcus faecium (i.e., E. faecium)) in T2D patients with poor compared to optimal glycemic control. Conclusions: This review provides evidence for glucose-lowering drug and gut microbiome interactions, highlighting the potential of gut microbiome modulators as co-adjuvants for T2D treatment.

Exploring Metabolomic Patterns in Type 2 Diabetes Mellitus and Response to Glucose-Lowering Medications-Review

The spectrum of information related to precision medicine in diabetes generally includes clinical data, genetics, and omics-based biomarkers that can guide personalized decisions on diabetes care. Given the remarkable progress in patient risk characterization, there is particular interest in using molecular biomarkers to guide diabetes management. Metabolomics is an emerging molecular approach that helps better understand the etiology and promises the identification of novel biomarkers for complex diseases. Both targeted or untargeted metabolites extracted from cells, biofluids, or tissues can be investigated by established high-throughput platforms, like nuclear magnetic resonance (NMR) and mass spectrometry (MS) techniques. Metabolomics is proposed as a valuable tool in precision diabetes medicine to discover biomarkers for diagnosis, prognosis, and management of the progress of diabetes through personalized phenotyping and individualized drug-response monitoring. This review offers an overview of metabolomics knowledge as potential biomarkers in type 2 diabetes mellitus (T2D) diagnosis and the response to glucose-lowering medications.

Disparities in SGLT2 Inhibitor or Glucagon-Like Peptide 1 Receptor Agonist Initiation Among Medicare-Insured Adults With CKD in the United States

Rationale & Objective

Information regarding disparities in initiating sodium/glucose cotransporter 2 inhibitors (SGLT2i) and glucagon-like peptide 1 receptor agonists (GLP-1RA) in patients with chronic kidney disease (CKD) is limited. We examined sociodemographic and clinical factors associated with the initiation of SGLT2i, GLP-1RA, or second-generation sulfonylureas in a Medicare Fee-For-Service patient population with CKD and type 2 diabetes.

Study Design

Retrospective cohort study.

Setting & Participants

The 20% random sample of Medicare Fee-For-Service claims, 2012-2018.

Exposures

Patients' sociodemographic and clinical factors.

Outcomes

Use of SGLT2i, GLP-1RA, or sulfonylureas.

Analytical Approach

Patients with a newly initiated prescription of SGLT2i, GLP-1RA, or second-generation sulfonylureas from January 1, 2013, to December 31, 2018, were identified. Multinomial logistic regression model was used to evaluate demographic and clinical factors associated with the initiation of SGLT2i, GLP-1RA, or second-generation sulfonylureas.

Results

The study cohort comprised 53,029 adults (aged greater than or equal to 18 years) with CKD and type 2 diabetes, of whom 10.0%, 17.4%, and 72.6% had a first prescription for SGLT2i, GLP-1RA, and sulfonylurea, respectively. Patients aged greater than or equal to 75 years versus those aged 65-74 years had lower odds to start SGLT2i or GLP-1RA compared with sulfonylureas. Black patients were associated with lower odds of initiation of SGLT2i (OR, 0.67; 95% CI, 0.61-0.74) and GLP-1RA (OR, 0.73; 95% CI, 0.68-0.79), compared with White patients. Hispanic and Asian patients had lower odds of initiation of GLP-1RA. Patients with cardiovascular disease or hyperlipidemia had higher odds to start SGLT2i or GLP-1RA.

Limitations

CKD and type 2 diabetes diagnosis; CKD stage; and patient clinical status were identified with diagnosis or procedure codes. There is potential for residual confounding with the use of retrospective data.

Conclusions

The results of this study identified disparities in the use of SGLT2i and GLP-1RA in patients with CKD. Black and older patients were significantly less likely to be initiated on SGLT2i or GLP-1RA than on second-generation sulfonylureas.

Metformin Treatment Among Men With Diabetes and the Risk of Prostate Cancer: A Population-Based Historical Cohort Study

There is conflicting evidence regarding the association between metformin treatment and prostate cancer risk in diabetic men. We investigated this association in a population-based Israeli cohort of 145,617 men aged 21–89 years with incident diabetes who were followed over the period 2002–2012. We implemented a time-dependent covariate Cox model, using weighted cumulative exposure to relate metformin history to prostate cancer risk, adjusting for use of other glucose-lowering medications, age, ethnicity, and socioeconomic status. To adjust for time-varying glucose control variables, we used inverse probability weighting of a marginal structural model. With 666,553 person-years of follow-up, 1,592 men were diagnosed with prostate cancer. Metformin exposure in the previous year was positively associated with prostate cancer risk (per defined daily dose; without adjustment for glucose control, hazard ratio (HR) = 1.53 (95% confidence interval (CI): 1.19, 1.96); with adjustment, HR = 1.42 (95% CI: 1.04, 1.94)). However, exposure during the previous 2–7 years was negatively associated with risk (without adjustment for glucose control, HR = 0.58 (95% CI: 0.37, 0.93); with adjustment, HR = 0.60 (95% CI: 0.33, 1.09)). These positive and negative associations with previous-year and earlier metformin exposure, respectively, need to be confirmed and better understood.

Role of Glucose-Lowering Medications in Erectile Dysfunction

Erectile dysfunction (ED) is a long-term complication of type 2 diabetes (T2D) widely known to affect the quality of life. Several aspects of altered metabolism in individuals with T2D may help to compromise the penile vasculature structure and functions, thus exacerbating the imbalance between smooth muscle contractility and relaxation. Among these, advanced glycation end-products and reactive oxygen species derived from a hyperglycaemic state are known to accelerate endothelial dysfunction by lowering nitric oxide bioavailability, the essential stimulus of relaxation. Although several studies have explained the pathogenetic mechanisms involved in the generation of erectile failure, few studies to date have described the efficacy of glucose-lowering medications in the restoration of normal sexual activity. Herein, we will present current knowledge about the main starters of the pathophysiology of diabetic ED and explore the role of different anti-diabetes therapies in the potential remission of ED, highlighting specific pathways whose activation or inhibition could be fundamental for sexual care in a diabetes setting.

Glucose-Lowering Medication Use in CKD: Analysis of US Medicare Beneficiaries Between 2007 and 2016

BACKGROUND

Information regarding the use of glucose-lowering medications in patients with chronic kidney disease (CKD) is limited.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

Medicare 5% random sample of patients with CKD with type 2 diabetes, 2007 to 2016.

PREDICTORS

Study year, CKD stage, low-income subsidy status, and demographic characteristics (age, sex, and race/ethnicity).

OUTCOMES

Trends in use of glucose-lowering medications.

ANALYTICAL APPROACH

Yearly cohorts of patients with CKD and type 2 diabetes were created. Descriptive statistics were used to report proportions of patients using glucose-lowering medications. To test overall trends in glucose-lowering medication classes, linear probability models with adjustment for age, sex, race/ethnicity, CKD stage, and low-income subsidy status were used.

RESULTS

Metformin use increased significantly from 32.7% in 2007 to 48.7% in 2016. Use of newer classes of glucose-lowering medications increased significantly, including dipeptidyl peptidase 4 inhibitors (5.6%, 2007; 21.7%, 2016), glucagon-like peptide 1 receptor agonists (2.3%, 2007; 6.1%, 2016), and sodium-glucose cotransporter 2 inhibitors (0.2%, 2013; 3.3%, 2016). Newer insulin analogue use increased from 37.2% in 2007 to 46.3% in 2013 and then remained steady. Use of sulfonylureas, thiazolidinediones, older insulins (human regular and neutral protamine Hagedorn), α-glucosidase inhibitors, amylin mimetics, and meglitinides decreased significantly. Insulin was the most highly used single medication class. Insulin use was higher among low-income subsidy than among non-low-income subsidy patients. Combination therapy was less common as CKD stage increased.

LIMITATIONS

Patients with CKD and type 2 diabetes and the CKD stages were identified with diagnosis codes and could not be verified through medical record review. Our results may not be generalizable to younger patients with CKD with type 2 diabetes.

CONCLUSIONS

Use of metformin and newer glucose-lowering medication classes is increasing in patients with CKD with type 2 diabetes. We anticipate that percentages of patients with CKD using these newer agents will increase.

Glucose-lowering medications and the risk of cancer: A methodological review of studies based on real-world data

AIM

To review the methodology of observational studies examining the association between glucose-lowering medications and cancer to identify the most common methodological challenges and sources of bias.

METHODS

We searched PubMed systematically to identify observational studies on glucose-lowering medications and cancer published between January 2000 and January 2016. We assessed the design and analytical methods used in each study, with a focus on their ability to achieve study validity, and further evaluated the prevalence of major methodological choices over time.

RESULTS

Of 155 studies evaluated, only 26% implemented a new-user design, 41% used an active comparator, 33% implemented a lag or latency period, and 51% adjusted for diabetes duration. Potential for immortal person-time bias was identified in 63% of the studies; 55% of the studies adjusted for variables measured during the follow-up without appropriate statistical methods. Aside from a decreasing trend in adjusting for variables measured during the follow-up, we observed no trends in methodological choices over time.

CONCLUSIONS

The prevalence of well-known design and analysis flaws that may lead to biased results remains high among observational studies on glucose-lowering medications and cancer, limiting the conclusions that can be drawn from these studies. Avoiding known pitfalls could substantially improve the quality and validity of real-world evidence in this field.

Claims-based studies of oral glucose-lowering medications can achieve balance in critical clinical variables only observed in electronic health records

AIM

To evaluate the extent to which balance in unmeasured characteristics of patients with type 2 diabetes (T2DM) was achieved in claims data, by comparing against more detailed information from linked electronic health records (EHR) data.

METHODS

Within a large US commercial insurance database and using a cohort design, we identified patients with T2DM initiating linagliptin or a comparator agent within class (ie, another dipeptidyl peptidase-4 inhibitor) or outside class (ie, pioglitazone or a sulphonylurea) between May 2011 and December 2012. We focused on comparators used at a similar stage of diabetes to linagliptin. For each comparison, 1:1 propensity score (PS) matching was used to balance >100 baseline claims-based characteristics, including proxies of diabetes severity and duration. Additional clinical data from EHR were available for a subset of patients. We assessed representativeness of the claims-EHR-linked subset, evaluated the balance of claims- and EHR-based covariates before and after PS-matching via standardized differences (SDs), and quantified the potential bias associated with observed imbalances.

RESULTS

From a claims-based study population of 166 613 patients with T2DM, 7219 (4.3%) patients were linked to their EHR data. Claims-based characteristics in the EHR-linked and EHR-unlinked patients were similar (SD < 0.1), confirming the representativeness of the EHR-linked subset. The balance of claims-based and EHR-based patient characteristics appeared to be reasonable before PS-matching and generally improved in the PS-matched population, to be SD < 0.1 for most patient characteristics and SD < 0.2 for select laboratory results and body mass index categories, which was not large enough to cause meaningful confounding.

CONCLUSION

In the context of pharmacoepidemiological research on diabetes therapy, choosing appropriate comparison groups paired with a new-user design and 1:1 PS matching on many proxies of diabetes severity and duration improves balance in covariates typically unmeasured in administrative claims datasets, to the extent that residual confounding is unlikely.