Stroke Prevention and Treatment in People With Type 2 Diabetes: Is There a Role for GLP-1 (Glucagon-Like Peptide-1) Analogues?

Stroke is a leading cause of disability and death, and people with type 2 diabetes (T2D) have a greater risk of stroke and death or disability from stroke. The underlying pathophysiology associating stroke and T2D is complicated by the association of risk factors for stroke frequently seen in people with T2D. Treatments to reduce the excess risk of new-onset stroke or to improve outcomes in people with T2D following stroke would be of major clinical interest. In practice, the focus of care in people with T2D remains treating risk factors for stroke, such as lifestyle and pharmacological interventions for hypertension, dyslipidemia, obesity, and glycemic control. More recently, cardiovascular outcome trials primarily designed to assess the cardiovascular safety of GLP-1RAs (glucagon-like peptide-1 receptor analogues) have consistently observed a reduced stroke risk in people with T2D. This is supported by several meta-analyses of cardiovascular outcome trials observing clinically important risk reductions in stroke. Moreover, phase II trials have described reductions in poststroke hyperglycemia in people with acute ischemic stroke suggestive of improved outcomes following admission to hospital with acute stroke. In this review, we discuss the increased risk of stroke in people with T2D and outline the key associated mechanisms responsible. We discuss the evidence from cardiovascular outcome trials exploring GLP-1RA use and highlight areas of potential interest for future work in this rapidly developing area of clinical research.

Obesity-related complications, healthcare resource use and weight loss strategies in six European countries: the RESOURCE survey.

BACKGROUND: Obesity-related complications (ORCs), such as type 2 diabetes (T2D) and cardiovascular disease, contribute considerably to the clinical and economic impacts of obesity. To obtain a holistic overview of health and weight management attempts for people with obesity in Europe, we designed the cross-sectional RESOURCE survey to collect data on comorbidities, healthcare resource use (HCRU) and weight loss strategies from people with obesity in France, Germany, Italy, Spain, Sweden and the UK. METHODS: Adults (≥18 years old) with self-reported body mass index (BMI) ≥30 kg/m2 who reported interacting with primary or secondary healthcare services in the past 12 months, but had not been pregnant during this time, were recruited from an existing consumer research panel. All data were self-reported via an online survey (May-June 2021). Weight changes over the past year were calculated from participants' estimated weights. RESULTS: Of the 1850 participants in the survey, 26.3% reported that they had ≥3 ORCs from a set of 15 conditions of interest. The most frequently reported ORCs were hypertension (39.3% of participants), dyslipidaemia (22.8%) and T2D (17.5%). Participants in obesity class III (BMI 40 to <70 kg/m2) were more likely to report multiple ORCs than those in lower obesity classes. The presence of multiple ORCs was linked to various types of HCRU, including a significantly increased chance of reporting hospitalization in the past year. Most participants (78.6%) had attempted to lose weight in the past year, but of those who also reported estimated weight changes, 73.4% had not experienced clinically meaningful weight loss of ≥5%. CONCLUSIONS: ORCs are common in people with obesity, and are linked to increased HCRU. Together with the low reported success rate of weight loss attempts, this highlights an unmet need in Europe for enhanced weight management support for people with obesity.

Real-world costs of obesity-related complications over eight years: a US retrospective cohort study in 28,500 individuals.

BACKGROUND: Obesity-related complications (ORCs) are associated with high costs for healthcare systems. We assessed the relationship between comorbidity burden, represented by both number and type of 14 specific ORCs, and total healthcare costs over time in people with obesity in the USA. METHODS: Adults (≥ 18 years old) identified from linked electronic medical records and administrative claims databases, with a body mass index measurement of 30-< 70 kg/m2 between 1 January 2007 and 31 March 2012 (earliest measurement: index date), and with continuous enrolment for ≥ 1 year pre index (baseline year) and ≥ 8 years post index, were included. Individuals were grouped by type and number of ORCs during the pre-index baseline year. The primary outcome was annual total adjusted direct per-person healthcare costs. RESULTS: Of 28,583 included individuals, 12,686 had no ORCs, 7242 had one ORC, 4180 had two ORCs and 4475 had three or more ORCs in the baseline year. Annual adjusted direct healthcare costs increased with the number of ORCs and over the 8-year follow-up. Outpatient costs were the greatest contributor to baseline annual direct costs, irrespective of the number of ORCs. For specific ORCs, costs generally increased gradually over the follow-up; the largest percentage increases from year 1 to year 8 were observed for chronic kidney disease (+ 78.8%) and type 2 diabetes (+ 47.8%). CONCLUSIONS: In a US real-world setting, the number of ORCs appears to be a cost driver in people with obesity, from the time of initial obesity classification and for at least the following 8 years.

Estimating the value of sodium-glucose cotransporter-2 inhibitors within the context of contemporary guidelines and the totality of evidence.

AIMS: To comprehensively estimate the cost-effectiveness of sodium glucose cotransporter-2 (SGLT2) inhibitor usage in the management of type 2 diabetes mellitus (T2DM) at established clinical review points, incorporating the totality of proven health benefits. MATERIALS AND METHODS: This study considered the cardio- and reno-protective effects of SGLT2 inhibitors using the Cardiff type 2 diabetes model. Conventional cost-effectiveness evaluations were undertaken for eligible populations at relevant intensification points reflecting the 2022 guidelines versus the 2015 National Institute of Health and Care Excellence (NICE) guidelines; incremental cost-effectiveness ratio lifetime trajectories and timepoints for complete cost-offset were estimated for each pathway. Treatment effects, utility decrements and costs (applied additively and discounted at 3.5%) were sourced from the published literature. RESULTS: For all subpopulations on treatment pathways reflecting the NG28-2022 guidelines, SGLT2 inhibitor introduction was cost-effective, becoming cost-saving between 2 and 16 years post-initiation. Despite increases in pharmacy costs, predicted lifetime costs were lower than for pathways reflecting the NG28-2015 guidelines, driven by a reduction in heart failure hospitalization and chronic kidney disease costs. Incremental gains in quality-adjusted life years (ranging from 0.58-1.12) resulted in dominance for the updated NG28-2022 guidance in all scenarios. CONCLUSIONS: Our results show that SGLT2 inhibitors have the potential to lower healthcare costs while improving health outcomes in eligible patient subpopulations.

Once-weekly semaglutide versus insulin aspart for the treatment of type 2 diabetes in the UK: A long-term cost-effectiveness analysis based on SUSTAIN 11.

AIM: To evaluate the long-term cost-effectiveness of once-weekly semaglutide 1 mg versus insulin aspart in the UK. MATERIALS AND METHODS: Long-term outcomes were projected over patients' lifetimes using the IQVIA CORE Diabetes Model (vers 9.0). SUSTAIN 11 was used to inform baseline cohort characteristics and treatment effects. Patients were modelled to receive once-weekly semaglutide plus basal insulin for 3 years before intensifying to basal-bolus insulin, compared with basal-bolus insulin for lifetimes in the aspart arm. Costs were accounted from a healthcare payer perspective in the UK, expressed in 2021 pounds sterling (GBP). RESULTS: Once-weekly semaglutide 1 mg was associated with improvements in quality-adjusted life expectancy of 0.18 quality-adjusted life years (QALYs) versus insulin aspart, due to a reduced incidence and delayed time to onset of diabetes-related complications. Direct costs were estimated to be GBP 800 higher with semaglutide, with higher treatment costs partially offset by cost savings from avoidance of diabetes-related complications. Once-weekly semaglutide 1 mg was therefore associated with an incremental cost-effectiveness ratio of GBP 4457 per QALY gained versus insulin aspart. CONCLUSIONS: Based on a willingness-to-pay threshold of GBP 20 000 per QALY gained, once-weekly semaglutide 1 mg was projected to be highly cost-effective versus insulin aspart for the treatment of type 2 diabetes in the UK.

The challenges and pitfalls of incorporating evidence from cardiovascular outcomes trials in health economic modelling of type 2 diabetes.

The clinical evidence base for evaluating modern type 2 diabetes interventions has expanded greatly in recent years, with numerous efficacious treatment options available (including dipeptidyl peptidase-4 inhibitors, glucagon-like peptide-1 receptor agonists and sodium-glucose cotransporter-2 inhibitors). The cardiovascular safety of these interventions has been assessed individually versus placebo in numerous cardiovascular outcomes trials (CVOTs), statistically powered to detect differences in a composite endpoint of major adverse cardiovascular events. There have been growing calls to incorporate these data in the long-term modelling of type 2 diabetes interventions because current diabetes models were developed prior to the conduct of the CVOTs and therefore rely on risk equations developed in the absence of these data. However, there are numerous challenges and pitfalls to avoid when using data from CVOTs. The primary concerns are around the heterogeneity of the trials, which have different study durations, inclusion criteria, rescue medication protocols and endpoint definitions; this results in significant uncertainty when comparing two or more interventions evaluated in separate CVOTs, as robust adjustment for these differences is difficult. Analyses using CVOT data inappropriately can dilute clear evidence from head-to-head clinical trials, and blur healthcare decision making. Calibration of existing models may represent an approach to incorporating CVOT data into diabetes modelling, but this can only offer a valid comparison of one intervention versus placebo based on a single CVOT. Ideally, model development should utilize patient-level data from CVOTs to prepare novel risk equations that can better model modern therapies for type 2 diabetes.

Eight-year trends in obesity-related complications and health care cost progression in a US population with obesity: A retrospective cohort study.

AIMS: Obesity-related complications (ORCs) impose a substantial health burden on affected individuals, and economic costs to health care systems. We examined ORCs and the progression of direct health care costs over 8 years, stratified by obesity class. MATERIALS AND METHODS: Adults with obesity were identified in linked US medical records and administrative claims databases. The index date was the first body mass index measurement of 30 to <70 kg/m2 between 1 January 2007 and 31 March 2012; a ≥8-year continuous enrolment post-index was required for inclusion. Diagnosis codes for five specific ORCs and total health care costs were recorded in each year of follow-up. Costs adjusted for clinical and demographic factors were also estimated. RESULTS: Of 28 583 eligible individuals, 17 892 had class I obesity, 6550 had class II obesity and 4141 had class III obesity. From baseline to year 8, the presence of type 2 diabetes and knee osteoarthritis doubled in all obesity classes, with even larger increases for chronic kidney disease and heart failure. Observed and adjusted total health care costs generally increased from the baseline year to year 8. The difference in costs between obesity classes increased over time: at year 1, individuals with class III obesity had 26.8% higher costs than those in class I, but at year 8, this difference was 40.7%. Outpatient costs constituted half of the total observed costs across obesity classes. CONCLUSIONS: ORC rates and health care costs increase over time, and are greater in higher obesity classes. This could be mitigated by approaches that limit obesity progression.

Healthcare costs and hospitalizations in US patients with type 2 diabetes and cardiovascular disease: A retrospective database study (OFFSET).

AIM: To investigate the budget implications of treatment with glucagon-like peptide-1 receptor agonists (GLP-1 RAs) versus other glucose-lowering treatment (here termed 'standard of care' [SoC]) during 2012-2019. MATERIALS AND METHODS: GLP-1 RA-naïve adults with type 2 diabetes (T2D) in the IBM MarketScan database with at least one glucose-lowering medication claim within 6 months after their first cardiovascular disease (CVD) hospitalization were included (index date was the date of first claim for a GLP-1 RA for the GLP-1 RA group, and the date of the first claim, independent of medication type, for the SoC group). Monthly healthcare costs and hospitalization risk over 12 months postindex date were compared for those who initiated a GLP-1 RA posthospitalization versus those with a claim for any other glucose-lowering medication. RESULTS: Postindex date, mean observed total costs were lower for patients receiving a GLP-1 RA compared with SoC ($3853 vs. $4288). In adjusted analysis, both groups had similar total healthcare costs (P = .56). This was driven by significantly lower inpatient and outpatient costs and higher drug costs in the GLP-1 RA group compared with SoC (P < .001). Risks of all-cause (adjusted hazard ratio: 0.85) and CVD-related hospitalization (0.76) were significantly lower in the GLP-1 RA group compared with SoC (P < .001). Similar results were observed in a subgroup with atherosclerotic CVD. CONCLUSIONS: These findings suggest that, in US patients with T2D and a CVD-related hospitalization, the added medical cost of treatment with GLP-1 RAs is offset by lower inpatient and outpatient care costs, resulting in budget neutrality against SoC.

Adherence to and persistence with antidiabetic medications and associations with clinical and economic outcomes in people with type 2 diabetes mellitus: A systematic literature review.

We designed a systematic literature review to identify available evidence on adherence to and persistence with antidiabetic medication in people with type 2 diabetes (T2D). Electronic screening and congress searches identified real-world noninterventional studies (published between 2010 and October 2020) reporting estimates of adherence to and persistence with antidiabetic medication in adults with T2D, and associations with glycaemic control, microvascular and/or macrovascular complications, hospitalizations and healthcare costs. Ninety-two relevant studies were identified, the majority of which were retrospective and reported US data. The proportions of patients considered adherent (median [range] 51.2% [9.4%-84.3%]) or persistent (median [range] 47.7% [16.9%-94.0%]) varied widely across studies. Multiple studies reported an association between greater adherence/persistence and greater reductions in glycated haemoglobin levels. Better adherence/persistence was associated with fewer microvascular and/or macrovascular outcomes, although there was little consistency across studies in terms of which outcomes were improved. More adherent and more persistent patients were typically less likely to be hospitalized or to have emergency department visits/admissions and spent fewer days in hospital annually than less adherent/persistent patients. Greater adherence and persistence were generally associated with lower hospitalization costs, higher pharmacy costs and lower or budget-neutral total healthcare costs compared with lower adherence/persistence. In conclusion, better adherence and persistence in people with T2D is associated with lower rates of microvascular and/or macrovascular outcomes and inpatient hospitalization, and lower or budget-neutral total healthcare expenditure. Education and treatment strategies to address suboptimal adherence and persistence are needed to improve clinical and economic outcomes.

The role of sodium-glucose co-transporter-2 inhibitors in frail older adults with or without type 2 diabetes mellitus.

Sodium-glucose co-transporter-2 (SGLT2) inhibitors offer significant outcome benefits beyond glucose lowering, including reduced risk of cardiovascular death, all-cause mortality, major adverse cardiovascular events, hospitalisations for heart failure and progression of renal disease. Considering these therapeutic effects, minimal incremental risk for hypoglycaemia and simplicity of administration, this drug class appears to be an attractive therapeutic option for older adults, and post hoc analysis of trial data provides support for the use of SGLT2 inhibitors in this population. Nevertheless, despite favourable clinical trial data, there has been some hesitance in clinical practice prescribing these drugs to older frail adults due to the limited therapeutic experience in this population and insufficient long-term safety data. In this review article, we evaluate the risk-benefit profile for the use of SGLT2 inhibitors in this population and suggest that rather than being a treatment to avoid, SGLT2 inhibitors should be considered a valid therapeutic option for older frail adults with or without diabetes.

A look to the future in non-alcoholic fatty liver disease: Are glucagon-like peptide-1 analogues or sodium-glucose co-transporter-2 inhibitors the answer?

The increasing prevalence of diabetes and non-alcoholic fatty liver disease (NAFLD) is a growing public health concern associated with significant morbidity, mortality and economic cost, particularly in those who progress to cirrhosis. Medical treatment is frequently limited, with no specific licensed treatments currently available for people with NAFLD. Its association with diabetes raises the possibility of shared mechanisms of disease progression and treatment. With the ever-growing interest in the non-glycaemic effects of diabetes medications, studies and clinical trials have investigated hepatic outcomes associated with the use of drug classes used for people with type 2 diabetes (T2D), such as glucagon-like peptide-1 (GLP-1) analogues or sodium-glucose co-transporter-2 (SGLT2) inhibitors. Studies exploring the use of GLP-1 analogues or SGLT2 inhibitors in people with NAFLD have observed improved measures of hepatic inflammation, liver enzymes and radiological features over short periods. However, these studies tend to have variable study populations and inconsistent reported outcomes, limiting comparison between drugs and drug classes. As these drugs appear to improve biomarkers of NAFLD, clinicians should consider their use in patients with NAFLD and T2D. However, further evidence with greater participant numbers and longer trial durations is required to support specific licensing for people with NAFLD. Larger trials would allow reporting of major adverse hepatic events, akin to cardiovascular and renal outcome trials, to be determined. This would provide a more meaningful evaluation of the impact of these drugs in NAFLD. Nevertheless, these drugs represent a future potential therapeutic avenue in this difficult-to-treat population and may beget significant health and economic impacts.

Cost-effectiveness of dapagliflozin as an adjunct to insulin for the treatment of type 1 diabetes mellitus in the United Kingdom.

AIMS: To assess the cost-effectiveness of dapagliflozin, a sodium-glucose co-transporter-2 (SGLT2) inhibitor, as an adjunct to insulin in adults with type 1 diabetes mellitus (T1DM) inadequately controlled by insulin alone in the UK setting. METHODS: A cost-utility analysis was conducted to compare dapagliflozin (5 mg or 10 mg) added to insulin versus insulin monotherapy (standard of care) over a lifetime horizon. Treatment efficacy and safety data were obtained from 52-week results of the DEPICT-1 and DEPICT-2 trials and a network meta-analysis of SGLT2 inhibitors in T1DM. Direct healthcare costs, life-years, and quality-adjusted life-years (QALYs) were estimated from a UK payer perspective and discounted at 3.5% annually, using the Cardiff T1DM Model. Sensitivity analyses assessed uncertainty in estimated incremental cost-effectiveness ratios (ICERs). RESULTS: Dapagliflozin 5 mg was associated with gains of 0.23 life-years and 0.42 QALYs, at an additional cost of £4240 per person; corresponding to an ICER of £10 143 versus standard of care. For dapagliflozin 10 mg, incremental life-years, QALYs and costs were 0.24, 0.49 and £2964, respectively; corresponding to an ICER of £6103 versus standard of care. In probabilistic sensitivity analysis, ICER estimates fell below £20 000/QALY in 78% to 90% of simulations. Cost-effectiveness results were sensitive to changes in baseline patient characteristics and treatment effects on glycated haemoglobin; however, ICERs remained below £20 000. CONCLUSIONS: At cost-effectiveness thresholds conventionally applied in the UK, dapagliflozin as an adjunct to insulin appears to be a cost-effective treatment option for people with T1DM inadequately controlled by insulin alone.

Systematic literature review and network meta-analysis of sodium-glucose co-transporter inhibitors vs metformin as add-on to insulin in type 1 diabetes.

AIMS: To identify and synthesize phase 3 and phase 4 randomized controlled trials (RCTs) of sodium-glucose co-transporter (SGLT) inhibitors and metformin as adjuncts to insulin in type 1 diabetes (T1DM) using network meta-analysis (NMA). MATERIALS AND METHODS: A systematic literature review (SLR) identified relevant RCTs of ≥12 Weeks duration. MEDLINE, Embase, the Cochrane Library and grey literature were searched through October 2018. NMAs indirectly compared SGLT inhibitors and metformin for change from baseline in HbA1c, weight, total daily insulin dose and systolic blood pressure at Week 24 to 26 and Week 52. Safety outcomes were also explored. RESULTS: Nine trials (N = 6780) were included in the SLR. NMAs indicated that all therapies performed better than placebo for the efficacy outcomes at both time points. Compared with metformin at Week 24 to 26, the SGLT inhibitors dapagliflozin (5 mg), sotagliflozin (200 mg) and empagliflozin (10 mg) had larger reductions in HbA1c (mean difference [MD] = -0.24, 95% credible interval [CrI], -0.41 to -0.07, MD = -0.23, 95% CrI, -0.39 to -0.08 and MD = -0.35, 95% CrI, -0.51 to -0.19, respectively) and in weight, which were sustained in sensitivity analyses. There were few differences observed in the results of safety outcomes, such as risk of diabetic ketoacidosis (DKA), which should be interpreted cautiously because of wide CrIs. CONCLUSIONS: Adjunctive use of SGLT inhibitors in T1DM can improve glycaemic control compared with metformin while enabling weight loss, with consistent efficacy across the class. However, these results are based on indirect evidence so confirmation in a head-to-head study would be valuable.

Transgenic maize phosphoenolpyruvate carboxylase alters leaf-atmosphere CO2 and 13CO2 exchanges in Oryza sativa.

The engineering process of C4 photosynthesis into C3 plants requires an increased activity of phosphoenolpyruvate carboxylase (PEPC) in the cytosol of leaf mesophyll cells. The literature varies on the physiological effect of transgenic maize (Zea mays) PEPC (ZmPEPC) leaf expression in Oryza sativa (rice). Therefore, to address this issue, leaf-atmosphere CO2 and 13CO2 exchanges were measured, both in the light (at atmospheric O2 partial pressure of 1.84 kPa and at different CO2 levels) and in the dark, in transgenic rice expressing ZmPEPC and wild-type (WT) plants. The in vitro PEPC activity was 25 times higher in the PEPC overexpressing (PEPC-OE) plants (~20% of maize) compared to the negligible activity in WT. In the PEPC-OE plants, the estimated fraction of carboxylation by PEPC (ß) was ~6% and leaf net biochemical discrimination against 13CO2[Formula: see text] was ~ 2‰ lower than in WT. However, there were no differences in leaf net CO2 assimilation rates (A) between genotypes, while the leaf dark respiration rates (Rd) over three hours after light-dark transition were enhanced (~ 30%) and with a higher 13C composition [Formula: see text] in the PEPC-OE plants compared to WT. These data indicate that ZmPEPC in the PEPC-OE rice plants contributes to leaf carbon metabolism in both the light and in the dark. However, there are some factors, potentially posttranslational regulation and PEP availability, which reduce ZmPEPC activity in vivo.

Association between diabetic eye disease and other complications of diabetes: Implications for care. A systematic review.

The aim of this systematic review was to examine the associations between diabetic retinopathy (DR) and the common micro- and macrovascular complications of diabetes mellitus, and how these could potentially affect clinical practice. A structured search of the PubMed database identified studies of patients with diabetes that assessed the presence or development of DR in conjunction with other vascular complications of diabetes. From 70 included studies, we found that DR is consistently associated with other complications of diabetes, with the severity of DR linked to a higher risk of the presence of, or of developing, other micro- and macrovascular complications. In particular, DR increases the likelihood of having or developing nephropathy and is also a strong predictor of stroke and cardiovascular disease, and progression of DR significantly increases this risk. Proliferative DR is a strong risk factor for peripheral arterial disease, which carries a risk of lower extremity ulceration and amputation. Additionally, our findings suggest that a patient with DR has an overall worse prognosis than a patient without DR. In conclusion, this analysis highlights the need for a coordinated and collaborative approach to patient management. Given the widespread use of DR screening programmes that can be performed outside of an ophthalmology office, and the overall cost-effectiveness of DR screening, the presence and severity of DR can be a means of identifying patients at increased risk for micro- and macrovascular complications, enabling earlier detection, referral and intervention with the aim of reducing morbidity and mortality among patients with diabetes. Healthcare professionals involved in the management of diabetes should encourage regular DR screening.

The value of maintaining normokalaemia and enabling RAASi therapy in chronic kidney disease.

BACKGROUND: People with chronic kidney disease (CKD) are at an increased risk of developing hyperkalaemia due to their declining kidney function. In addition, these patients are often required to reduce or discontinue guideline-recommended renin-angiotensin-aldosterone system inhibitor (RAASi) therapy due to increased risk of hyperkalaemia. This original research developed a model to quantify the health and economic benefits of maintaining normokalaemia and enabling optimal RAASi therapy in patients with CKD. METHODS: A patient-level simulation model was designed to fully characterise the natural history of CKD over a lifetime horizon, and predict the associations between serum potassium levels, RAASi use and long-term outcomes based on published literature. The clinical and economic benefits of maintaining sustained potassium levels and therefore avoiding RAASi discontinuation in CKD patients were demonstrated using illustrative, sensitivity and scenario analyses. RESULTS: Internal and external validation exercises confirmed the predictive capability of the model. Sustained potassium management and ongoing RAASi therapy were associated with longer life expectancy (+ 2.36 years), delayed onset of end stage renal disease (+ 5.4 years), quality-adjusted life-year gains (+ 1.02 QALYs), cost savings (£3135) and associated net monetary benefit (£23,446 at £20,000 per QALY gained) compared to an absence of RAASi to prevent hyperkalaemia. CONCLUSION: This model represents a novel approach to predicting the long-term benefits of maintaining normokalaemia and enabling optimal RAASi therapy in patients with CKD, irrespective of the strategy used to achieve this target, which may support decision making in healthcare.

Serum potassium as a predictor of adverse clinical outcomes in patients with chronic kidney disease: new risk equations using the UK clinical practice research datalink.

BACKGROUND: To address a current paucity of European data, this study developed equations to predict risks of mortality, major adverse cardiac events (MACE) and renin angiotensin-aldosterone system inhibitor (RAASi) discontinuation using time-varying serum potassium and other covariates, in a UK cohort of chronic kidney disease (CKD) patients. METHODS: This was a retrospective observational study of adult CKD patients listed on the Clinical Practice Research Datalink, with a first record of CKD (stage 3a-5, pre-dialysis) between 2006 and 2015. Patients with heart failure at index were excluded. Risk equations developed using Poisson Generalized Estimating Equations were utilised to estimate adjusted incident rate ratios (IRRs) between serum potassium and adverse outcomes, and identify other predictive clinical factors. RESULTS: Among 191,964 eligible CKD patients, 86,691 (45.16%), 30,629 (15.96%) and 9440 (4.92%) experienced at least one hyperkalaemia episode, when defined using serum potassium concentrations 5.0-< 5.5 mmol/L, 5.5-< 6.0 mmol/L and ≥ 6.0 mmol/L, respectively. Relative to the reference category (4.5 to < 5.0 mmol/L), adjusted IRRs for mortality and MACE exhibited U-shaped associations with serum potassium, with age being the most important predictor of both outcomes (P < 0.0001). A J-shaped association between serum potassium and RAASi discontinuation was observed; estimated glomerular filtration rate was most predictive of RAASi discontinuation (P < 0.0001). CONCLUSIONS: Hyperkalaemia was associated with increased mortality and RAASi discontinuation risk. These risk equations represent a valuable tool to predict clinical outcomes among CKD patients; and identify those likely to benefit from strategies that treat hyperkalaemia, prevent RAASi discontinuation, and effectively manage serum potassium levels.

Managing glycaemia in older people with type 2 diabetes: A retrospective, primary care-based cohort study, with economic assessment of patient outcomes.

AIMS: To describe the relative health and economic outcomes associated with different second-line therapeutic approaches to manage glycaemia in older type 2 diabetes patients requiring escalation from metformin monotherapy. MATERIALS AND METHODS: The Clinical Practice Research Datalink database was used to inform a retrospective observational cohort study of patients with type 2 diabetes treated with metformin monotherapy requiring escalation (addition or switch) to a second-line oral regimen from January 1, 2008 to December 31, 2014. Primary outcomes included time to first event (any event, myocardial infarction [MI], stroke, or composite of MI/stroke [major adverse cardiovascular event; MACE]) and total event rate. The health economic consequences associated with the choice of second-line treatment in older patients were assessed using the CORE Diabetes Model. RESULTS: A total of 10 484 patients were included; the majority escalated to second-line treatment with metformin + sulphonylurea (SU; 42%) or switched to SU monotherapy (28%). In multivariate adjusted analyses, total event rates for MACE with metformin + dipeptidyl peptidase-4 (DPP-4) inhibitor were significantly lower than with metformin + SU (0.61, 95% confidence interval [CI] 0.39-0.98), driven by a lower MI rate in the metformin + DPP-4 inhibitor group (0.52, 95% CI 0.27-0.99). Economic analyses estimated that metformin + DPP-4 inhibitor treatment was associated with the largest gain in health benefit, and cost-effectiveness ratios were favourable (<£30 000 per quality-adjusted life-year) for all second-line treatment scenarios. CONCLUSIONS: With respect to treatment choice, data from the present study support the notion of prescribing beyond metformin + SU, as alternative regimens have been shown to be associated with reduced outcomes risk and value for money.

An alternative approach to modelling HbA1c trajectories in patients with type 2 diabetes mellitus.

AIMS: Time-dependent HbA1c trajectories in health economic models of type 2 diabetes mellitus (T2DM) are typically informed by the UK Prospective Diabetes Study (UKPDS). However, this approach may not accurately predict HbA1c progression in patients who do not conform to the demographic profile of the original UKPDS cohort. This study aimed to develop an alternative mathematical model (MM) to simulate HbA1c progression in T2DM. MATERIALS AND METHODS: A systematic literature review identified studies, published between 2005 and 2015, that reported HbA1c in adult T2DM patients over a minimum duration of 18 months. Pooled data from eligible studies were used to develop an alternative MM equation for HbA1c progression, which was then contrasted with the UKPDS 68 progression equation in illustrative scenarios. RESULTS: A total of 68 studies were eligible for data extraction (mean follow-up time 4.1 years). HbA1c progression was highly heterogeneous across studies, varying with baseline HbA1c, treatment group and patient age. The MM equation was fitted with parameters for mean baseline HbA1c (8.3%), initial change in HbA1c (-0.62%) and upper quartile of maximum observed HbA1c (9.3%). Differences in HbA1c trajectories between the MM and UKPDS approaches altered the timing of therapy escalation in illustrative scenarios. CONCLUSIONS: The MM represents an alternative approach to simulate HbA1c trajectories in T2DM models, as UKPDS data may not adequately reflect the heterogeneity of HbA1c profiles observed in clinical studies. However, the choice of approach should ultimately be determined by the characteristics of individual patients under consideration and the clinical face validity of the modelled trajectories.

Kranz and single-cell forms of C4 plants in the subfamily Suaedoideae show kinetic C4 convergence for PEPC and Rubisco with divergent amino acid substitutions.

The two carboxylation reactions performed by phosphoenolpyruvate carboxylase (PEPC) and ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) are vital in the fixation of inorganic carbon for C4 plants. The abundance of PEPC is substantially elevated in C4 leaves, while the location of Rubisco is restricted to one of two chloroplast types. These differences compared with C3 leaves have been shown to result in convergent enzyme optimization in some C4 species. Investigation into the kinetic properties of PEPC and Rubisco from Kranz C4, single cell C4, and C3 species in Chenopodiaceae s. s. subfamily Suaedoideae showed that these major carboxylases in C4 Suaedoideae species lack the same mutations found in other C4 systems which have been examined; but still have similar convergent kinetic properties. Positive selection analysis on the N-terminus of PEPC identified residues 364 and 368 to be under positive selection with a posterior probability >0.99 using Bayes empirical Bayes. Compared with previous analyses on other C4 species, PEPC from C4 Suaedoideae species have different convergent amino acids that result in a higher K m for PEP and malate tolerance compared with C3 species. Kinetic analysis of Rubisco showed that C4 species have a higher catalytic efficiency of Rubisco (k catc in mol CO2 mol(-1) Rubisco active sites s(-1)), despite lacking convergent substitutions in the rbcL gene. The importance of kinetic changes to the two-carboxylation reactions in C4 leaves related to amino acid selection is discussed.