Exploration of Residual Confounding in Analyses of Associations of Metformin Use and Outcomes in Adults With Type 2 Diabetes

Data-driven simulations to assess the impact of study imperfections in time-to-event analyses

Quantitative bias analysis (QBA) permits assessment of the expected impact of various imperfections of the available data on the results and conclusions of a particular real-world study. This article extends QBA methodology to multivariable time-to-event analyses with right-censored endpoints, possibly including time-varying exposures or covariates. The proposed approach employs data-driven simulations, which preserve important features of the data at hand while offering flexibility in controlling the parameters and assumptions that may affect the results. First, the steps required to perform data-driven simulations are described, and then two examples of real-world time-to-event analyses illustrate their implementation and the insights they may offer. The first example focuses on the omission of an important time-invariant predictor of the outcome in a prognostic study of cancer mortality, and permits separating the expected impact of confounding bias from noncollapsibility. The second example assesses how imprecise timing of an interval-censored event-ascertained only at sparse times of clinic visits-affects its estimated association with a time-varying drug exposure. The simulation results also provide a basis for comparing the performance of two alternative strategies for imputing the unknown event times in this setting. The R scripts that permit the reproduction of our examples are provided.

Exploration of Pharmacological Mechanisms of Dapagliflozin against Type 2 Diabetes Mellitus through PI3K-Akt Signaling Pathway based on Network Pharmacology Analysis and Deep Learning Technology

BACKGROUND

Dapagliflozin is commonly used to treat type 2 diabetes mellitus (T2DM). However, research into the specific anti-T2DM mechanisms of dapagliflozin remains scarce.

OBJECTIVE

This study aimed to explore the underlying mechanisms of dapagliflozin against T2DM.

METHODS

Dapagliflozin-associated targets were acquired from CTD, SwissTargetPrediction, and SuperPred. T2DM-associated targets were obtained from GeneCards and DigSee. VennDiagram was used to obtain the overlapping targets of dapagliflozin and T2DM. GO and KEGG analyses were performed using clusterProfiler. A PPI network was built by STRING database and Cytoscape, and the top 30 targets were screened using the degree, maximal clique centrality (MCC), and edge percolated component (EPC) algorithms of CytoHubba. The top 30 targets screened by the three algorithms were intersected with the core pathway-related targets to obtain the key targets. DeepPurpose was used to evaluate the binding affinity of dapagliflozin with the key targets.

RESULTS

In total, 155 overlapping targets of dapagliflozin and T2DM were obtained. GO and KEGG analyses revealed that the targets were primarily enriched in response to peptide, membrane microdomain, protein serine/threonine/tyrosine kinase activity, PI3K-Akt signaling pathway, MAPK signaling pathway, and AGE-RAGE signaling pathway in diabetic complications. AKT1, PIK3CA, NOS3, EGFR, MAPK1, MAPK3, HSP90AA1, MTOR, RELA, NFKB1, IKBKB, ITGB1, and TP53 were the key targets, mainly related to oxidative stress, endothelial function, and autophagy. Through the DeepPurpose algorithm, AKT1, HSP90AA1, RELA, ITGB1, and TP53 were identified as the top 5 anti-targets of dapagliflozin.

CONCLUSION

Dapagliflozin might treat T2DM mainly by targeting AKT1, HSP90AA1, RELA, ITGB1, and TP53 through PI3K-Akt signaling.

Comparative effectiveness of sodium-glucose cotransporter-2 inhibitors for recurrent nephrolithiasis among patients with pre-existing nephrolithiasis or gout: target trial emulation studies

OBJECTIVE

To emulate target trials comparing recurrence of nephrolithiasis among patients with pre-existing nephrolithiasis (overall and stratified by concomitant gout) initiating sodium-glucose cotransporter-2 (SGLT-2) inhibitors versus an active comparator.

DESIGN

Target trial emulation studies.

SETTING

Canadian population database, January 2014 to June 2022.

PARTICIPANTS

20 146 patients with nephrolithiasis and type 2 diabetes, including those with concomitant gout at baseline, a high risk group.

INTERVENTIONS

Initiation of an SGLT-2 inhibitor or glucagon-like peptide-1 (GLP-1) receptor agonist, with a dipeptidyl peptidase-4 (DPP-4) inhibitor as alternative comparator.

MAIN OUTCOME MEASURES

The primary outcome was recurrent nephrolithiasis events ascertained from diagnoses during emergency department visits, hospital admissions, or outpatient visits. Secondary outcomes included nephrolithiasis resulting in hospital admission or emergency department visits and flare-up of gout, as well as a positive control outcome (genital infection) and negative control outcomes (osteoarthritis encounter and appendicitis). Poisson and Cox proportional hazards regression models were used (primary analyses), as well as overlap weighting.

RESULTS

After inverse probability of treatment weighting, 1924 recurrent nephrolithiasis events occurred among the 14 456 weighted patients who used an SGLT-2 inhibitor (105.3 per 1000 person years), compared with 853 events among the 5877 weighted patients who used a GLP-1 receptor agonist (156.4 per 1000 person years). The adjusted rate ratio was 0.67 (95% confidence interval (CI) 0.57 to 0.79) and rate difference was -51 (95% CI -63 to -40) per 1000 person years, with a number needed to treat (NNT) of 20. Among those with recently active nephrolithiasis, the absolute rate difference was 219 per 1000 person years (NNT of 5). Protective associations persisted for nephrolithiasis events that required emergency department visits, hospital admissions, or procedures, and when an SGLT-2 inhibitor was compared with a DPP-4 inhibitor (rate ratio 0.73 (0.68 to 0.78), rate difference -38 (-46 to -29) per 1000 person years (NNT of 26)). Protective associations also persisted among patients with nephrolithiasis and concomitant gout, with a rate ratio of 0.67 (0.57 to 0.79) and rate difference of -53 (95% CI -78 to -27) per 1000 person years versus a GLP-1 receptor agonist (NNT of 19), and 0.63 (0.55 to 0.72) and-62 (-81 to -42) per 1000 person years, respectively, versus a DPP-4 inhibitor (NNT of 16). Furthermore, SGLT-2 inhibitor use was associated with a lower rate of gout flare-ups (rate ratio 0.72, 0.54 to 0.95, rate difference -16, -31 to -1 per 1000 person years) compared with GLP-1 receptor agonists (0.65, 0.52 to 0.82, and -21, -33 to -9 per 1000 person years) compared with DPP-4 inhibitors. SGLT-2 inhibitor initiators showed higher risk of genital infection (eg, hazard ratio 2.21, 95% CI 1.68 to 2.90, and rate difference 13 per 1000 person years), but no altered risk of osteoarthritis encounter (0.87, 0.68 to 1.1, and -2 per 1000 person years) or appendicitis (1.07, 0.69 to 1.67, and 1 per 1000 person years). Results were similar when propensity score overlap weighting was applied.

CONCLUSIONS

The benefits associated with SGLT-2 inhibitor for patients with nephrolithiasis in these target trial emulations suggest they may be a useful addition to current treatments to simultaneously manage nephrolithiasis recurrence and comorbidities, including gout.

Sodium-Glucose Cotransporter-2 Inhibitors vs Sulfonylureas for Gout Prevention Among Patients With Type 2 Diabetes Receiving Metformin

Importance

Sodium-glucose cotransporter type 2 inhibitors (SGLT2i) are a revolutionary treatment for type 2 diabetes (T2D) with cardiovascular, kidney, and serum urate-lowering benefits.

Objective

To compare risk of incident gout and rate of recurrent flares between patients with T2D initiating SGLT2i vs sulfonylurea, most common second-line glucose-lowering therapy, when added to metformin monotherapy.

Design, Setting, and Participants

This sequential, propensity score-matched, new-user comparative effectiveness study using target trial emulation framework included adults with T2D receiving metformin monotherapy in a Canadian general population database from January 1, 2014, to June 30, 2022.

Exposures

Initiation of SGLT2i vs sulfonylurea.

Main Outcomes and Measures

The primary outcome was incident gout diagnosis, ascertained by emergency department (ED), hospital, outpatient, and medication dispensing records. Secondary outcomes were gout-primary hospitalizations and ED visits and major adverse cardiovascular events (MACE), as well as recurrent flare rates among prevalent gout patients. Heart failure (HF) hospitalization was assessed as positive control outcome and osteoarthritis encounters as negative control. For target trial emulations, we used Cox proportional hazards and Poisson regressions with 1:1 propensity score matching (primary analysis) and overlap weighting (sensitivity analysis). The analysis was conducted from September to December, 2023.

Results

Among 34 604 propensity score matched adults with T2D initiating SGLT2i or sulfonylurea (20 816 [60%] male, mean [SD] age, 60 [12.4] years), incidence of gout was lower among SGLT2i initiators (4.27 events per 1000 person-years) than sulfonylurea initiators (6.91 events per 1000 person-years), with a hazard ratio (HR) of 0.62 (95% CI, 0.48-0.80) and a rate difference (RD) of -2.64 (95% CI, -3.99 to -1.29) per 1000 person-years. Associations persisted regardless of sex, age, or baseline diuretic use. SGLT2i use was also associated with fewer recurrent flares among gout patients (rate ratio, 0.67; 95% CI, 0.55-0.82; and RD, -20.9; 95% CI, -31.9 to -10.0 per 1000 person-years). HR and RD for MACE associated with SGLT2i use were 0.87 (95% CI, 0.77-0.98) and -3.58 (95% CI, -6.19 to -0.96) per 1000 person-years. For control outcomes, SGLT2i users had lower risk of HF (HR, 0.53; 95% CI, 0.38-0.76), as expected, with no difference in osteoarthritis (HR, 1.11; 95% CI, 0.94-1.34). Results were similar when applying propensity score overlap weighting.

Conclusions

In this population-based cohort study, the gout and cardiovascular benefits associated with SGLT2i in these target trial emulations may guide selection of glucose-lowering therapy in patients with T2D, at risk for or already with gout.

Long-term benefits of dapagliflozin on renal outcomes of type 2 diabetes under routine care: a comparative effectiveness study on propensity score matched cohorts at low renal risk

Background

Despite the overall improvement in care, people with type 2 diabetes (T2D) experience an excess risk of end-stage kidney disease. We evaluated the long-term effectiveness of dapagliflozin on kidney function and albuminuria in patients with T2D.

Methods

We included patients with T2D who initiated dapagliflozin or comparators from 2015 to 2020. Propensity score matching (PSM) was performed to balance the two groups. The primary endpoint was the change in estimated glomerular filtration rate (eGFR) from baseline to the end of observation. Secondary endpoints included changes in albuminuria and loss of kidney function.

Findings

We analysed two matched groups of 6197 patients each. The comparator group included DPP-4 inhibitors (40%), GLP-1RA (22.3%), sulphonylureas (16.1%), pioglitazone (8%), metformin (5.8%), or acarbose (4%). Only 6.4% had baseline eGFR <60 ml/min/1.73 m2 and 15% had UACR >30 mg/g. During a mean follow-up of 2.5 year, eGFR declined significantly less in the dapagliflozin vs comparator group by 1.81 ml/min/1.73 m2 (95% C.I. from 1.13 to 2.48; p < 0.0001). The mean eGFR slope was significantly less negative in the dapagliflozin group by 0.67 ml/min/1.73 m2/year (95% C.I. from 0.47 to 0.88; p < 0.0001). Albuminuria declined significantly in new-users of dapagliflozin within 6 months and remained on average 44.3 mg/g lower (95% C.I. from -66.9 to -21.7; p < 0.0001) than in new-users of comparators. New-users of dapagliflozin had significantly lower rates of new-onset CKD, loss of kidney function, and a composite renal outcome. Results were confirmed for all SGLT2 inhibitors, in patients without baseline CKD, and when GLP-1RA were excluded from comparators.

Interpretation

Initiating dapagliflozin improved kidney function outcomes and albuminuria in patients with T2D and a low renal risk.

Funding

Funded by the Italian Diabetes Society and partly supported by a grant from AstraZeneca.

Comparative Effectiveness of Sodium-Glucose Cotransporter-2 Inhibitors for Recurrent Gout Flares and Gout-Primary Emergency Department Visits and Hospitalizations : A General Population Cohort Study

BACKGROUND

Sodium-glucose cotransporter-2 inhibitors (SGLT2is) decrease serum urate levels, but whether this translates into prevention of recurrent flares among patients with gout and gout-primary emergency department (ED) visits or hospitalizations is unknown.

OBJECTIVE

To compare gout flares and cardiovascular events among patients with gout initiating SGLT2is versus dipeptidyl peptidase 4 inhibitors (DPP-4is), another second-line glucose-lowering agent not associated with serum urate levels or cardiovascular risk.

DESIGN

Propensity score-matched, new-user cohort study.

SETTING

General population database from 1 January 2014 to 30 June 2022.

PARTICIPANTS

Patients with gout and type 2 diabetes.

MEASUREMENTS

The primary outcome was recurrent gout flare counts ascertained by ED, hospitalization, outpatient, and medication dispensing records. Secondary outcomes included myocardial infarction and stroke; genital infection (positive control) and osteoarthritis encounter (negative control) were also assessed. Poisson and Cox proportional hazards regressions were used with 1:1 propensity score matching (primary analysis) and overlap weighting (sensitivity analysis).

RESULTS

After propensity score matching, the flare rate was lower among SGLT2i initiators than DPP-4i initiators (52.4 and 79.7 events per 1000 person-years, respectively), with a rate ratio (RR) of 0.66 (95% CI, 0.57 to 0.75) and a rate difference (RD) of -27.4 (CI, -36.0 to -18.7) per 1000 person-years. The corresponding RR and RD for gout-primary ED visits and hospitalizations were 0.52 (CI, 0.32 to 0.84) and -3.4 (CI, -5.8 to -0.9) per 1000 person-years, respectively. The corresponding hazard ratio (HR) and RD for myocardial infarction were 0.69 (CI, 0.54 to 0.88) and -7.6 (CI, -12.4 to -2.8) per 1000 person-years; the HR for stroke was 0.81 (CI, 0.62 to 1.05). Those who initiated SGLT2is showed higher risk for genital infection (HR, 2.15 [CI, 1.39 to 3.30]) and no altered risk for osteoarthritis encounter (HR, 1.07 [CI, 0.95 to 1.20]). Results were similar when propensity score overlap weighting was applied.

LIMITATION

Participants had concurrent type 2 diabetes.

CONCLUSION

Among patients with gout, SGLT2is may reduce recurrent flares and gout-primary ED visits and hospitalizations and may provide cardiovascular benefits.

PRIMARY FUNDING SOURCE

National Institute of Arthritis and Musculoskeletal and Skin Diseases.