Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

Prediction of myopia onset with refractive error measured using non-cycloplegic subjective refraction: the WEPrOM Study

Background/aims

To evaluate the predictive performance of various predictors, including non-cycloplegic refractive error, for risk of myopia onset under pragmatic settings.

Methods

The Wenzhou Medical University Essilor Progression and Onset of Myopia Study is a prospective cohort study of schoolchildren aged 6–10 years from two elementary schools in Wenzhou, China. Non-cycloplegic refraction, ocular biometry and accommodation measurements were performed. Myopia was defined as spherical equivalent (SE) ≤−0.5 diopter (D). ORs using multivariable logistic regression were determined. Area under the curve (AUC) evaluation for predictors was performed.

Results

Schoolchildren who attended both baseline and 2-year follow-up were analysed (N=1022). Of 830 non-myopic children at baseline, the 2-year incidence of myopia was 27.6% (95% CI, 24.2% to 31.3%). Female gender (OR=2.2), more advanced study grades (OR=1.5), less hyperopic SE (OR=11.5 per D), longer axial length (AL; OR=2.3 per mm), worse presenting visual acuity (OR=2.3 per decimal), longer near work time (OR=1.1 per hour/day) and lower magnitude of positive relative accommodation (PRA; OR=1.4 per D) were associated with myopia onset. PRA (AUC=0.66), SE (AUC=0.64) and AL (AUC=0.62) had the highest AUC values. The combination of age, gender, parental myopia, SE, AL and PRA achieved an AUC of 0.74.

Conclusion

Approximately one in four schoolchildren had myopia onset over a 2-year period. The predictors of myopia onset include lower magnitude of PRA, less hyperopic SE, longer AL and female gender. Of these, non-cycloplegic SE and PRA were the top single predictors, which can facilitate risk profiling for myopia onset.

Perspectives on the production of milk on small-holder dairy farms and its utilisation in developing countries

The profitability of milk production in the developing world varies widely among farming systems. This results from poor animal productivity and an inefficient marketing-chain structure in which farmers seldom profit from their dairying activities. The lack of chilling facilities for milk storage and the need to adulterate the raw product along the market chain to enhance profit margins means that consumers are not well catered for. Co-operative selling of milk, along with the acquisition of higher-quality feeds and veterinary medicines, has boosted the financial resilience of small-holder farming communities worldwide, although, in many regions, the co-operative model has not succeeded largely through a lack of trust between families even within the communities. Commercial reality dictates that farming communities work together to achieve financial sustainability, although the model adopted for each community may differ. Although milk has traditionally provided many consumers with their only source of animal protein, vitamin and minerals, we are now discovering its many other virtues, particularly in relation to cognitive development and memory retention and the provision of antioxidants. The impact of milk-processing technology on some of these remarkable properties requires further investigation to ensure that milk consumers worldwide benefit from these positive attributes.

Presentation and clinical course of Wolfram (DIDMOAD) syndrome from North India

AIMS

Wolfram syndrome, also known as DIDMOAD, is a relatively rare inherited neurodegenerative disorder, first evident in childhood as an association of juvenile-onset diabetes mellitus and optic atrophy, followed by diabetes insipidus and deafness. The aim of the study was to examine the clinical profile of patients with DIDMOAD syndrome presenting to a tertiary care hospital in north India.

METHODS

Clinical presentation of juvenile-onset diabetes mellitus fulfilling the diagnosis of Wolfram syndrome was studied using a prepared standardized form.

RESULTS

Subjects with juvenile-onset non-autoimmune diabetes mellitus attending the diabetic clinic at a tertiary care centre in north India were followed for 10 years and a diagnosis of fully developed Wolfram syndrome was confirmed in seven individuals. The series consisted of five male and two female patients with a mean age of 17.5 ±7.34 years. Two subjects had consanguinity and none had any other family member affected. Optic atrophy was present in all, sensorineural hearing loss in 4/7, central diabetes insipidus in 4/7 and nephrogenic diabetes insipidus in 2/7 subjects. The new associations found were: spastic myoclonus, short stature with pancreatic malabsorption, nephrogenic diabetes insipidus, cyanotic heart disease and choledocholithiasis with cholangitis. Genetic analysis revealed mutation in exon 8 of the WFS1 gene in all the cases studied.

CONCLUSIONS

The present clinical series of Wolfram syndrome reveals a varied clinical presentation of the syndrome and some new associations.

Predictors of onset of depression and anxiety in the year after diagnosis of breast cancer

BACKGROUND

Depression and anxiety are common after diagnosis of breast cancer. We examined to what extent these are recurrences of previous disorder and, controlling for this, whether shame, self-blame and low social support after diagnosis predicted onset of depression and anxiety subsequently.

METHOD

Women with primary breast cancer who had been treated surgically self-reported shame, self-blame, social support and emotional distress post-operatively. Psychiatric interview 12 months later identified those with adult lifetime episodes of major depression (MD) or generalized anxiety disorder (GAD) before diagnosis and onset over the subsequent year. Statistical analysis examined predictors of each disorder in that year.

RESULTS

Of the patients, two-thirds with episodes of MD and 40% with episodes of GAD during the year after diagnosis were experiencing recurrence of previous disorder. Although low social support, self-blame and shame were each associated with both MD and GAD after diagnosis, they did not mediate the relationship of disorder after diagnosis with previous disorder. Low social support, but not shame or self-blame, predicted recurrence after controlling for previous disorder.

CONCLUSIONS

Anxiety and depression during the first year after diagnosis of breast cancer are often the recurrence of previous disorder. In predicting disorder following diagnosis, self-blame and shame are merely markers of previous disorder. Low social support is an independent predictor and therefore may have a causal role.

Mortality rates in diabetic patients from a community-based population compared to local age/sex matched controls

Using a population-based cohort from 10 general practices in East Dorset, the mortality rate of diabetic patients compared to non-diabetic controls was investigated during 8 years follow-up. From a total population of 90660, 917 diabetic patients were identified; 693 (75%) with non-insulin-dependent (Type 2) diabetes and 224 (25%) with insulin-dependent (Type 1) diabetes. A control group of 917 non-diabetic subjects were selected, matched by age and sex. After 8 years, significantly more diabetic patients (334 or 36.4%) had died than controls (219 or 24%), (odds ratio (OR) 1.99, 95% CI 1.60-2.47). Compared with the controls, the odds ratio of all causes of mortality for diabetic men was 1.89 (CI 1.4-2.54) and for diabetic women 2.16 (CI 1.57-2.96). Compared with controls, the odds ratio for mortality from circulatory disease was significantly increased for diabetic patients 2.0 (CI 1.5-2.6) but mortality for respiratory disease or neoplasms was not significantly different (OR 0.7, CI 0.4-1.2 and OR 0.7, CI 0.6-1.0, respectively). Control data were lower than would be expected from national database data. The diabetic population had a significantly higher mortality than controls, both from all causes and circulatory diseases. Our data incidentally show the importance of appropriate controls for estimating the impact of a chronic disease.

Mortality rates in diabetic patients from a community-based population compared to local age/sex matched controls

Using a population-based cohort from 10 general practices in East Dorset, the mortality rate of diabetic patients compared to non-diabetic controls was investigated during 8 years follow-up. From a total population of 90660, 917 diabetic patients were identified; 693 (75%) with non-insulin-dependent (Type 2) diabetes and 224 (25%) with insulin-dependent (Type 1) diabetes. A control group of 917 non-diabetic subjects were selected, matched by age and sex. After 8 years, significantly more diabetic patients (334 or 36.4%) had died than controls (219 or 24%), (odds ratio (OR) 1.99, 95% CI 1.60-2.47). Compared with the controls, the odds ratio of all causes of mortality for diabetic men was 1.89 (CI 1.4-2.54) and for diabetic women 2.16 (CI 1.57-2.96). Compared with controls, the odds ratio for mortality from circulatory disease was significantly increased for diabetic patients 2.0 (CI 1.5-2.6) but mortality for respiratory disease or neoplasms was not significantly different (OR 0.7, CI 0.4-1.2 and OR 0.7, CI 0.6-1.0, respectively). Control data were lower than would be expected from national database data. The diabetic population had a significantly higher mortality than controls, both from all causes and circulatory diseases. Our data incidentally show the importance of appropriate controls for estimating the impact of a chronic disease.