Serum T50 predicts cardiovascular mortality in individuals with type 2 diabetes: A prospective cohort study.

BACKGROUND AND AIMS: Individuals with type 2 diabetes (T2D) have a higher risk of cardiovascular disease, compared with those without T2D. The serum T50 test captures the transformation time of calciprotein particles in serum. We aimed to assess whether serum T50 predicts cardiovascular mortality in T2D patients, independent of traditional risk factors. METHODS: We analyzed 621 individuals with T2D in this prospective cohort study. Cox regression models were performed to test the association between serum T50 and cardiovascular and all-cause mortality. Causes of death were categorized according to ICD-10 codes. Risk prediction improvement was assessed by comparing Harrell's C for models without and with T50. RESULTS: The mean age was 64.2 ± 9.8 years, and 61% were male. The average serum T50 time was 323 ± 63 min. Higher age, alcohol use, high-sensitive C-reactive protein, and plasma phosphate were associated with lower serum T50 levels. Higher plasma triglycerides, venous bicarbonate, sodium, magnesium, and alanine aminotransferase were associated with higher serum T50 levels. After a follow-up of 7.5[5.4-10.7] years, each 60 min decrease in serum T50 was associated with an increased risk of cardiovascular (fully adjusted HR 1.32, 95% CI 1.08-1.50, and p = 0.01) and all-cause mortality (HR 1.15, 95%CI 1.00-1.38, and p = 0.04). Results were consistent in sensitivity analyses after exclusion of individuals with estimated glomerular filtration rate <45 or <60 mL/min/1.73 m2 and higher plasma phosphate levels. CONCLUSIONS: Serum T50 improves prediction of cardiovascular and all-cause mortality risk in individuals with T2D. Serum T50 may be useful for risk stratification and to guide therapeutic strategies aiming to reduce cardiovascular mortality in T2D.

Urinary Post-Translationally Modified Fetuin-A Protein Is Associated with Increased Risk of Graft Failure in Kidney Transplant Recipients.

INTRODUCTION: Urinary fetuin-A has been identified as a biomarker for acute kidney injury and is proposed as a biomarker for early detection of kidney function decline. We investigated whether fetuin-A could serve as a marker of graft failure in kidney transplant recipients (KTRs). METHODS: Data of KTR with a functioning graft ≥1 year that were enrolled in the TransplantLines Food and Nutrition Biobank and cohort study were used. Graft failure was defined as the need for re-transplantation or (re-)initiation of dialysis. Urinary fetuin-A was measured using an enzyme-linked immunosorbent assay kit that detected post-translationally modified fetuin-A in the urine (uPTM-FetA). In the main analyses, 24h uPTM-FetA excretion was used. In the sensitivity analyses, we excluded the outliers in 24h uPTM-FetA excretion, and we used uPTM-FetA concentration and uPTM-FetA concentration indexed for creatinine instead of 24h uPTM-FetA excretion. RESULTS: A total of 627 KTRs (age 53 ± 13 years, 42% females) were included at 5.3 (1.9-12.2) years after transplantation. The estimated glomerular filtration rate (eGFR) was 52 ± 20 mL/min/1.73 m2 and uPTM-FetA excretion was 34 (17-74) µg/24 h. During a median follow-up of 5.3 (4.5-6.0) years after baseline measurements, 73 (12%) KTRs developed graft failure. The association of 24h uPTM-FetA excretion with increased risk of graft failure was not constant over time, with increased risk only observed after 3 years from baseline measurements, independent of potential confounders including kidney function and 24 h urinary protein excretion (hazard ratio per doubling of 24h uPTM-FetA excretion = 1.31; 95% confidence interval = 1.06-1.61). This finding was robust in the sensitivity analyses. CONCLUSIONS: Our findings suggest that uPTM-FetA can be used as a marker for early detection of graft failure in KTR. Further studies are needed to confirm our findings.

Urinary Fetuin-A Fragments Predict Progressive Estimated Glomerular Filtration Rate Decline in Two Independent Type 2 Diabetes Cohorts of Different Ethnicities.

INTRODUCTION: There is a great clinical need for novel markers to predict kidney function decline in patients with type 2 diabetes. We explored the potential of posttranslationally modified fetuin-A fragments in urine (uPTM-FetA) as such a marker. METHODS: We included patients with type 2 diabetes from two independent, nonoverlapping prospective cohort studies. A cut-off for uPTM-FetA, measured via ELISA method, was determined using the Youden index in the primary cohort of patients with type 2 diabetes from Taiwan. Kidney endpoint was defined as an estimated glomerular filtration rate (eGFR) decline ≥30% from baseline, reaching of an eGFR <15 mL/min/1.73 m2, or a need of renal replacement therapy. Prospective associations were assessed in Cox regression models. All analyses were replicated in a cohort of patients with type 2 diabetes from the Netherlands. RESULTS: In total, 294 patients with type 2 diabetes (age 61 ± 10 years, 55% male, eGFR 88 ± 16 mL/min/1.73 m2) were included in the primary cohort. During a follow-up of median 4.6 years, 42 participants (14%) experienced the kidney endpoint. Using the defined cut-off, a high uPTM-FetA was associated with a higher risk of renal function decline (Plog-rank < 0.0001). This association was similar in subgroups depending on albuminuria. This association remained, independent of age, sex, baseline eGFR, albuminuria, HbA1c, and other potential confounders (HR: 9.94; 95% CI: 2.96-33.40; p < 0.001 in the final model). Analyses in the validation cohort (376 patients with type 2 diabetes, age 64 ± 11 years, 66% male, eGFR 76 ± 24 mL/min/1.73 m2) using the same cut-off yielded similar results. CONCLUSION: uPTM-FetA was independently associated with kidney function decline in patients with type 2 diabetes validated in a 2-cohort study. The significant additive predictive power of this biomarker from conventional risk factors suggests its clinical use for renal function progression in patients with type 2 diabetes.

Low Urinary Potassium Excretion Is Associated with Higher Risk of All-Cause Mortality in Patients with Type 2 Diabetes: Results of the Dutch Diabetes and Lifestyle Cohort Twente (DIALECT).

BACKGROUND: Low 24-h urinary potassium excretion, reflecting low potassium intake, is associated with premature mortality in the general population. OBJECTIVES: To determine whether urinary potassium excretion is associated with all-cause mortality in patients with type 2 diabetes. METHODS: We performed a prospective cohort study in 654 patients with type 2 diabetes in the Diabetes and Lifestyle Cohort Twente (DIALECT). Sex-specific tertiles of 24-h urinary potassium excretion were analyzed in a multivariable Cox regression model with all-cause mortality. The outpatient program of the hospital uses a continuous surveillance system by the municipal registry of death to ensure up-to-date information on the patient's status (alive or deceased). FFQs were used to study associations between urinary potassium excretion and food products. RESULTS: Urinary potassium excretion at baseline was 84 ± 25 mmol/d in males and 65 ± 22 mmol/d in females, corresponding to estimated potassium intakes of 4250 ± 1270 mg/d and 3300 ± 875 mg/d. During a median follow-up of 5.2 (IQR: 2.7-7.9] y, 96 participants died. In a fully adjusted model, patients in the lowest sex-specific tertile had a higher risk of all-cause mortality, compared with patients in the highest sex-specific tertile (HR: 2.09; 95% CI: 1.06, 4.10; P = 0.03). Patients in the lowest sex-specific tertile consumed fewer fruits and vegetables, dairy, coffee, and potato products compared with patients in the highest sex-specific tertile (all P < 0.05). CONCLUSIONS: Low potassium intake is associated with a higher risk of all-cause mortality in Dutch patients with type 2 diabetes. Intervention studies are needed to determine whether potassium supplementation improves longevity in patients with type 2 diabetes. This trial was registered in the Dutch Trial Register as NTR trial code 5855.

Cadmium, active smoking and renal function deterioration in patients with type 2 diabetes.

BACKGROUND: Cadmium is an established nephrotoxin, present in cigarette smoke. We investigated the hazards of cadmium concentration and smoking status on renal function deterioration. We furthermore discerned whether the association of cadmium concentration with renal function deterioration is attributable to smoking status. METHODS: Prospective analyses were performed in data of 226 patients of the DIAbetes and LifEstyle Cohort Twente-1 (DIALECT). Cadmium concentrations were determined from EDTA whole-blood. Smoking status was determined via a self-administered questionnaire. Renal function deterioration was defined as need for renal replacement therapy or a persistent decline of ≥30% in estimated glomerular filtration rate from baseline for at least 3 months. Multivariable Cox regression models were performed to calculate hazard ratios (HRs) for the association between smoking status, cadmium concentration and renal function deterioration. RESULTS: Median (interquartile range) whole-blood cadmium was 2.9 (1.9-5.1) nmol/L. Active smokers had significantly higher cadmium [7.4 (3.3-11.7) nmol/L] compared with never smokers [2.6 (1.6-4.2) nmol/L] and former smokers [2.8 (1.8-4.8) nmol/L]. During median follow-up for 6 (4-8) years, renal function deterioration occurred in 60 persons (27%). Both cadmium and active smoking were associated with an increased hazard for renal function deterioration [HR 1.37, 95% confidence interval (95% CI) 1.06-1.78 and 3.77, 95% CI 1.72-8.29, respectively]. In a multivariable model with both smoking status and cadmium concentration included, active smokers have an increased risk for renal function deterioration (HR 3.00, 95% CI 1.22-7.40), while the association between cadmium and renal function deterioration lost statistical significance (HR 1.16, 95% CI 0.87-1.54). CONCLUSIONS: Active smoking is associated with progressive kidney disease in type 2 diabetes. The association between cadmium concentration and renal function deterioration in large part determined by smoking status. Extensive assessment of smoking status may be useful in patients with type 2 diabetesat high risk of kidney damage.

Overall and inter-individual effect of four different drug classes on soluble urokinase plasminogen activator receptor in type 1 and type 2 diabetes.

AIM: To evaluate the effect of four different drug classes on soluble urokinase plasminogen activator receptor (suPAR), a biomarker active in multiple inflammatory processes and a risk factor for complications, in people with type 1 and type 2 diabetes. METHODS: We conducted post hoc analyses of a randomized, open-label, crossover trial including 26 adults with type 1 and 40 with type 2 diabetes with urinary albumin-creatinine ratio ≥30 and ≤500 mg/g assigned to 4-week treatments with telmisartan 80 mg, empagliflozin 10 mg, linagliptin 5 mg and baricitinib 2 mg, separated by 4-week washouts. Plasma suPAR was measured before and after each treatment. SuPAR change after each treatment was calculated and, for each individual, the best suPAR-reducing drug was identified. Subsequently, the effect of the best individual drug was compared against the mean of the other three drugs. Repeated-measures linear mixed-effects models were employed. RESULTS: The baseline median (interquartile range) plasma suPAR was 3.5 (2.9, 4.3) ng/mL. No overall effect on suPAR levels was observed for any one drug. The individual best-performing drug varied, with baricitinib being selected for 20 participants (30%), followed by empagliflozin for 19 (29%), linagliptin for 16 (24%) and telmisartan for 11 (17%). The individual best-performing drug reduced suPAR by 13.3% (95% confidence interval [CI] 3.7, 22.8; P = 0.007). The difference in suPAR response between the individual best-performing drug and the other three was -19.7% (95% CI -23.1, -16.3; P < 0.001). CONCLUSIONS: We demonstrated no overall effect of 4-week treatment with telmisartan, empagliflozin, linagliptin or baricitinib on suPAR. However, individualization of treatment might significantly reduce suPAR levels.

Effects of dapagliflozin on volume status and systemic haemodynamics in patients with chronic kidney disease without diabetes: Results from DAPASALT and DIAMOND.

AIMS: To assess the effect of sodium-glucose cotransporter-2 inhibitor dapagliflozin on natriuresis, blood pressure (BP) and volume status in patients with chronic kidney disease (CKD) without diabetes. MATERIALS AND METHODS: We performed a mechanistic open-label study (DAPASALT) to evaluate the effects of dapagliflozin on 24-hour sodium excretion, 24-hour BP, extracellular volume, and markers of volume status during a standardized sodium diet (150 mmol/d) in six patients with CKD. In parallel, in a placebo-controlled double-blind crossover trial (DIAMOND), we determined the effects of 6 weeks of dapagliflozin on markers of volume status in 53 patients with CKD. RESULTS: In DAPASALT (mean age 65 years, mean estimated glomerular filtration rate [eGFR] 39.4 mL/min/1.73 m2 , median urine albumin:creatinine ratio [UACR] 111 mg/g), dapagliflozin did not change 24-hour sodium and volume excretion during 2 weeks of treatment. Dapagliflozin was associated with a modest increase in 24-hour glucose excretion on Day 4, which persisted at Day 14 and reversed to baseline after discontinuation. Mean 24-hour systolic BP decreased by -9.3 (95% confidence interval [CI] -19.1, 0.4) mmHg after 4 days and was sustained at Day 14 and at wash-out. Renin, angiotensin II, urinary aldosterone and copeptin levels increased from baseline. In DIAMOND (mean age 51 years, mean eGFR 59.0 mL/min/1.73 m2 , median UACR 608 mg/g), compared to placebo, dapagliflozin increased plasma renin (38.5 [95% CI 7.4, 78.8]%), aldosterone (19.1 [95% CI -5.9, 50.8]%), and copeptin levels (7.3 [95% CI 0.1, 14.5] pmol/L). CONCLUSIONS: During a standardized sodium diet, dapagliflozin decreased BP but did not increase 24-hour sodium and volume excretion. The lack of increased natriuresis and diuresis may be attributed to activation of intra-renal compensatory mechanisms to prevent excessive water loss.

Renal haemodynamic response to sodium-glucose cotransporter-2 inhibition does not depend on protein intake: An analysis of three randomized controlled trials.

High protein intake may increase intraglomerular pressure through dilation of the afferent arteriole. Sodium-glucose cotransporter-2 (SGLT2) inhibitors may reduce intraglomerular pressure through activation of tubuloglomerular feedback. Given these opposing effects, we assessed whether the effect of dapagliflozin on glomerular filtration rate (GFR) and urinary albumin-to-creatinine ratio (UACR) was modified by estimated dietary protein intake using data from three separate randomized controlled trials (DELIGHT, IMPROVE and DIAMOND). The median protein intake was 58.4, 63.6 and 90.0 g/d, respectively. In the DELIGHT trial (n = 233), dapagliflozin compared to placebo caused an acute and reversible dip in GFR of 2.1 and 2.2 mL/min/1.73 m2 , and reduced UACR by 20.5% and 28.4% in participants with high and low protein intake, respectively. Similarly, in IMPROVE (n = 30) and DIAMOND (n = 53), the effect of dapagliflozin on GFR and UACR was comparable in participants with high and low protein intake (all P for interaction > 0.40). This post hoc, exploratory analysis of three clinical trials suggests that dietary protein intake does not modify the individual response of clinical kidney variables to dapagliflozin.

The role of renal hypoxia in the pathogenesis of diabetic kidney disease: a promising target for newer renoprotective agents including SGLT2 inhibitors?

Diabetic kidney disease is the most common cause of end-stage kidney disease and poses a major global health problem. Finding new, safe, and effective strategies to halt this disease has proven to be challenging. In part that is because the underlying mechanisms are complex and not fully understood. However, in recent years, evidence has accumulated suggesting that chronic hypoxia may be the primary pathophysiological pathway driving diabetic kidney disease and chronic kidney disease of other etiologies and was called the chronic hypoxia hypothesis. Hypoxia is the result of a mismatch between oxygen delivery and oxygen demand. The primary determinant of oxygen delivery is renal perfusion (blood flow per tissue mass), whereas the main driver of oxygen demand is active sodium reabsorption. Diabetes mellitus is thought to compromise the oxygen balance by impairing oxygen delivery owing to hyperglycemia-associated microvascular damage and exacerbate oxygen demand owing to increased sodium reabsorption as a result of sodium-glucose cotransporter upregulation and glomerular hyperfiltration. The resultant hypoxic injury creates a vicious cycle of capillary damage, inflammation, deposition of the extracellular matrix, and, ultimately, fibrosis and nephron loss. This review will frame the role of chronic hypoxia in the pathogenesis of diabetic kidney disease and its prospect as a promising therapeutic target. We will outline the cellular mechanisms of hypoxia and evidence for renal hypoxia in animal and human studies. In addition, we will highlight the promise of newer imaging modalities including blood oxygenation level-dependent magnetic resonance imaging and discuss salutary interventions such as sodium-glucose cotransporter 2 inhibition that (may) protect the kidney through amelioration of renal hypoxia.

A Self-management Approach for Dietary Sodium Restriction in Patients With CKD: A Randomized Controlled Trial.

RATIONALE & OBJECTIVE: Patients with chronic kidney disease (CKD) are particularly sensitive to dietary sodium. We evaluated a self-management approach for dietary sodium restriction in patients with CKD. STUDY DESIGN: Randomized controlled trial. SETTING & PARTICIPANTS: Nephrology outpatient clinics in 4 Dutch hospitals. 99 adults with CKD stages 1 to 4 or a functioning (estimated glomerular filtration rate≥25mL/min/1.73m2) kidney transplant, hypertension, and sodium intake>130mmol/d. INTERVENTION: Routine care was compared with routine care plus a web-based self-management intervention including individual e-coaching and group meetings implemented over a 3-month intervention period, followed by e-coaching over a 6-month maintenance period. OUTCOMES: Primary outcomes were sodium excretion after the 3-month intervention and after the 6-month maintenance period. Secondary outcomes were blood pressure, proteinuria, costs, quality of life, self-management skills, and barriers and facilitators for implementation. RESULTS: Baseline estimated glomerular filtration rate was 55.0±22.0mL/min/1.73m2. During the intervention period, sodium excretion decreased in the intervention group from 188±8 (SE) to 148±8mmol/d (P<0.001), but did not change significantly in the control group. At 3 months, mean sodium excretion was 24.8 (95% CI, 0.1-49.6) mmol/d lower in the intervention group (P=0.049). At 3 months, systolic blood pressure (SBP) decreased in the intervention group from 140±3 to 132±3mm Hg (P<0.001), but was unchanged in the control group. Mean difference in SBP across groups was-4.7 (95% CI, -10.7 to 1.3) mm Hg (P=0.1). During the maintenance phase, sodium excretion increased in the intervention group, but remained lower than at baseline at 160±8mmol/d (P=0.01), while it decreased in the control group from 174±9 at the end of the intervention period to 154±9mmol/d (P=0.001). Consequently, no difference in sodium excretion between groups was observed after the maintenance phase. There was no difference in SBP between groups after the maintenance phase. LIMITATIONS: Limited power, postrandomization loss to follow-up, Hawthorne effect, lack of dietary data, short-term follow-up. CONCLUSIONS: A coaching intervention reduced sodium intake at 3 months. Efficacy during the maintenance phase was diminished, possibly due to inadvertent adoption of the intervention by the control group. FUNDING: Grant funding from the Netherlands Organization for Health Research and Development and the Dutch Kidney Foundation. TRIAL REGISTRATION: Registered at ClinicalTrials.gov with study number NCT02132013.

Fibroblast Growth Factor 23 and Adverse Clinical Outcomes in Type 2 Diabetes: a Bitter-Sweet Symphony.

PURPOSE OF REVIEW: Fibroblast growth factor 23 (FGF23) is a key phosphate-regulating hormone that has been associated with adverse outcomes in patients with chronic kidney disease (CKD). Emerging data suggest that FGF23 plays a specific role in type 2 diabetes, partly independent of kidney function. We aimed to summarize current literature on the associations between FGF23 and outcomes in patients with type 2 diabetes with or without CKD. RECENT FINDINGS: Several cohort studies have shown strong associations between plasma FGF23 and cardiovascular outcomes in diabetic CKD. Moreover, recent data suggest that FGF23 are elevated and may also be a risk factor for cardiovascular disease and mortality in type 2 diabetes patients without CKD, although the magnitude of the association is smaller than in CKD patients. Diabetes-related factors may influence plasma FGF23 levels, and a higher FGF23 levels seem to contribute to a higher cardiovascular and mortality risk in patients with type 2 diabetes. Although this risk may be relevant in diabetic individuals with preserved kidney function, it is strongly accentuated in diabetic nephropathy. Future studies should clarify if FGF23 is merely a disease severity marker or a contributor to adverse outcomes in type 2 diabetes and establish if antidiabetic medication can modify FGF23 levels.

Exposure-response relationships for the sodium-glucose co-transporter-2 inhibitor dapagliflozin with regard to renal risk markers.

AIMS: To quantitate the consistency of an individual's plasma exposure to dapagliflozin upon re-exposure, and to investigate whether the individual's systemic exposure to dapagliflozin explains inter-individual variation in response to dapagliflozin with regard to multiple renal risk markers. METHODS: Data were used from a crossover randomized clinical trial that assessed the albuminuria-lowering effect of dapagliflozin in 33 people with type 2 diabetes and elevated albuminuria. Fifteen participants were exposed twice to dapagliflozin. Trough plasma concentrations of dapagliflozin were measured for each participant at steady state. Dapagliflozin plasma concentrations were measured by liquid chromatography tandem mass spectrometry, and pharmacokinetic characteristics were simulated based on a population pharmacokinetic model. Linear mixed-effects models were used to quantify the exposure-response relationships. RESULTS: The median plasma concentration after first and second exposure to dapagliflozin was 5.3 ng/mL vs 4.6 ng/mL, respectively (P = 0.78). Lin's concordance correlation coefficient between occasions was 0.73 (P < 0.0021). Every 100 ng.h/mL increment in area under the dapagliflozin plasma concentration curve was associated with a decrease in log-transformed urinary albumin:creatinine ratio (ß = -5.9, P < 0.01), body weight (ß = -0.3, P < 0.01) and estimated glomerular filtration rate (ß = -0.7, P = 0.01) and an increase in urinary glucose excretion (ß = 17.0, P < 0.001). CONCLUSION: An individual's exposure to dapagliflozin is consistent upon re-exposure and correlates with pharmacodynamic response in renal risk markers.

Determinants of Increased Serum Calprotectin in Patients with Type 2 Diabetes Mellitus.

Circulating calprotectin is a potential biomarker for endovascular inflammation in type 2 diabetes mellitus (T2DM). We investigated the determinants of calprotectin and its relationship with the presence of cardiovascular disease (CVD) in 362 T2DM patients included in the Diabetes and Lifestyle Cohort Twente-1 (DIALECT-1) study. Lifestyle exposures, including nutrition, were determined by validated questionnaires. CVD was defined as coronary artery diseases, strokes, and peripheral artery diseases. Median serum calprotectin levels were 1.04 mg/L [IQR: 0.73-1.46 mg/L] and were higher in women (1.11 mg/L) than men (0.96 mg/L, p = 0.007). Current smoking was a major independent determinant of circulating calprotectin, with a 51% higher calprotectin compared to never smoking (p < 0.001). Albuminuria (p = 0.011), former smoking (p = 0.023), and intake of mono- and disaccharides (p = 0.005) also contributed independently to circulating calprotectin. Each incremental increase in calprotectin level was associated with 1.36-times higher odds for CVD (95% CI 1.04-1.77, p = 0.026). In the current study, calprotectin was the only inflammatory parameter significantly associated with CVD. The strong association of circulating calprotectin with smoking, a well-known direct cause of vascular inflammation, and also with CVD, stresses the urge for further research to define its role as a biomarker in T2DM.

Detection of carnosinase-1 in urine of healthy individuals and patients with type 2 diabetes: correlation with albuminuria and renal function.

Low serum carnosinase (CN-1) concentrations are associated with low risk for development of diabetic nephropathy (DN) in patients with type 2 diabetes (T2D). Although CN-1 is expressed in the kidney, urinary CN-1 (CNU) excretion and its pathological relevance in patients with T2D have not been investigated to date. The present study therefore assessed the extent of CNU excretion in healthy subjects (n = 243) and in patients with T2D (n = 361) enrolled in the DIAbetes and LifEstyle Cohort Twente-1 (DIALECT-1) in relation to functional renal parameters. CNU was detected in a high proportion of healthy individuals, 180 (74%); median CNU excretion was 0.25 mg/24 h [(IQR 0-0.65 mg/24 h]. In patients with T2D the prevalence and extent of CNU increased in parallel with albuminuria (r = 0.59, p < 0.0001; median CNU 0.1 vs 0.2 vs 1.5 mg/24 h, p < 0.0001; prevalence of CNU 61 vs. 81 vs. 97% p < 0.05 in normo- (n = 241), micro- (n = 80) and macroalbuminuria (n = 40), respectively). Patients with estimated glomerular filtration rate (eGFR) < 30 ml/min/1.73 m2 displayed higher median CNU excretion rates in comparison to patients with preserved eGFR (> 90 ml/min/1.73 m2) (1.36 vs 0.13 mg/24 h, p < 0.05). Backward stepwise multivariate linear regression analysis revealed albuminuria, eGFR and glycosuria to be independent factors of CNU excretion rates, all together explaining 37% of variation of CNU excretion rates (R2 = 0.37, p < 0.0001). These results show for the first time that CN-1 can be detected in urine and warrants prospective studies to assess the relevance of CNU for renal function deterioration in diabetes patients.

Effects of dapagliflozin on urinary metabolites in people with type 2 diabetes.

AIM: To assess the effects of the sodium-glucose co-transporter-2 (SGLT2) inhibitor dapagliflozin on a pre-specified panel of 13 urinary metabolites linked to mitochondrial metabolism in people with type 2 diabetes and elevated urine albumin levels. MATERIALS AND METHODS: Urine and plasma samples were used from a double-blind, randomized, placebo-controlled crossover trial in 31 people with type 2 diabetes, with an albumin:creatinine ratio >100 mg/g, and who were on a stable dose of an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Dapagliflozin or placebo treatment periods each lasted 6 weeks, with a 6-week washout period in between. Urinary and plasma metabolites were quantified by gas-chromatography mass spectrometry, corrected for creatinine level, and then combined into a single-valued urinary metabolite index. Fractional excretion of the metabolites was calculated. RESULTS: All 13 urinary metabolites were detectable. After 6 weeks of dapagliflozin therapy, nine of the 13 metabolites were significantly increased from baseline. The urinary metabolite index increased by 42% (95% confidence interval [CI] 8.5 to 85.6; P = .01) with placebo versus 121% (95% CI 69 to 189; P < .001) with dapaglifozin. The placebo-adjusted effect was 56% (95% CI 11 to 118; P = .012). In plasma, seven of the 13 metabolites were detectable, and none was modified by dapagliflozin. CONCLUSIONS: Dapagliflozin significantly increased a panel of urinary metabolites previously linked to mitochondrial metabolism. These data support the hypothesis that SGLT2 inhibitors improve mitochondrial function, and improvements in mitochondrial function could be a mechanism for kidney protection. Future studies with longer treatment duration and clinical outcomes are needed to confirm the clinical impact of these findings.

Sex differences in renin-angiotensin-aldosterone system affect extracellular volume in healthy subjects.

Several studies reported sex differences in aldosterone. It is unknown whether these differences are associated with differences in volume regulation. Therefore we studied both aldosterone and extracellular volume in men and women on different sodium intakes. In healthy normotensive men ( n = 18) and premenopausal women ( n = 18) we investigated plasma aldosterone, blood pressure, and extracellular volume (125I-iothalamate), during both low (target intake 50 mmol Na+/day) and high sodium intake (target intake 200 mmol Na+/day) in a crossover setup. Furthermore, we studied the adrenal response to angiotensin II infusion (0.3, 1.0, and 3.0 ng·kg-1·min-1 for 1 h) on both sodium intakes. Men had a significantly higher plasma aldosterone, extracellular volume, and systolic blood pressure than women during high sodium intake ( P < 0.05). During low sodium intake, extracellular volume and blood pressure were higher in men as well ( P < 0.05), whereas the difference in plasma aldosterone was no longer significant ( P = 0.252). The adrenal response to exogenous angiotensin II was significantly lower in men than in women on both sodium intakes. Constitutive sex differences in the regulation of aldosterone, characterized by a higher aldosterone and a lower adrenal response to exogenous angiotensin II infusion in men, are associated with a higher extracellular volume and blood pressure in men. These findings suggest that sex differences in the regulation of aldosterone contribute to differences in volume regulation between men and women.

Does SGLT2 inhibition with dapagliflozin overcome individual therapy resistance to RAAS inhibition?

Individual patients show a large variation in their response to renin-angiotensin-aldosteron system (RAAS) inhibition (RAASi), both in surrogates such as albuminuria and in hard renal outcomes. Sodium-glucose co-transporter 2 inhibitors (SGLT2) have been shown to lower albuminuria and to confer cardiovascular and, possibly, renal protection. To establish whether individual therapy resistance to RAASi can be overcome by adding an SGLT2 inhibitor, we assessed individual albuminuria responses in patients exposed to both RAASi and the SGLT2 inhibitor dapagliflozin. We used data from a randomized controlled cross-over trial designed to assess the albuminuria-lowering effect of 6-week treatment with dapagliflozin 10 mg/d. We extracted from the electronic medical records data on the albuminuria response upon initiation of RAASi before the trial period, and analysed individual albuminuria responses to RAASi and to dapagliflozin. We retrieved data on RAASi for 26 patients (age, 62 years [SD, 8]; female gender, 6 [23%]; 24-hour urinary albumin excretion, 521 [187-921] mg/24 h). The mean albuminuria-lowering response to RAASi was 26.5% (range, -76.1% to 135.1%). The addition of dapagliflozin res in a further reduction of 34.9%, (range, -83.9 to 94.2). Interestingly, the albuminuria response to RAASi significantly correlated with the response to dapagliflozin (Pearson correlation coefficient, 0.635 [95% CI, 0.328-0.821]; P < .001), indicating that patients who did not respond to RAASi also did not respond to dapagliflozin. We concluded that individual therapy resistance to RAASi cannot be overcome with the addition of a completely different class of drugs, SGLT2 inhibitors. These data suggest that the individual drug response is an intrinsic individual characteristic, possibly unrelated to the type of intervention, unless the mode of action of dapagliflozin on albuminuria is through the RAAS.

Effects of the SGLT-2 inhibitor dapagliflozin on glomerular and tubular injury markers.

The mechanisms by which SGLT-2 inhibitors lower albuminuria are incompletely understood. We assessed in a post-hoc analysis of a cross-over trial the effects of the SGLT2 inhibitor dapagliflozin on glomerular markers (IgG to IgG4 and IgG to albumin), tubular markers (urinary KIM-1, NGAL and LFABP) and inflammatory markers (urinary MCP-1 and IL-6) to provide more insight into kidney protective effects. Dapagliflozin decreased albuminuria by 43.9% (95% CI, 30.3%-54.8%) and eGFR by 5.1 (2.0-8.1) mL/min/1.73m2 compared to placebo. Dapagliflozin did not change glomerular charge or size selectivity index compared to placebo. Dapagliflozin decreased urinary KIM-1 excretion by 22.6% (0.3%-39.8%; P = .05) and IL-6 excretion by 23.5% (1.4%-40.6%; P = .04) compared to placebo, whereas no changes in NGAL, LFABP and MCP-1 were observed. During dapagliflozin treatment, changes in albuminuria correlated with changes in eGFR (r = 0.36; P = .05) and KIM-1 (r = 0.39; P = .05). In conclusion, the albuminuria-lowering effect of 6 weeks of dapagliflozin therapy may be the result of decreased intraglomerular pressure or reduced tubular cell injury.

Glycaemic control in the diabetes and Lifestyle Cohort Twente: A cross-sectional assessment of lifestyle and pharmacological management on Hba1c target achievement.

The majority of patients with type 2 diabetes do not reach target levels of glycated haemoglobin (HbA1c < 7%). We investigated the prevalence of HbA1c-target achievement and opportunities afforded by lifestyle and pharmacological treatment to increase target achievement. We performed cross-sectional analyses of baseline data from the Diabetes and Lifestyle Cohort Twente-1 (DIALECT-1). Patients were divided according to (1) HbA1c <53 and ≥53 mmol/mol (<7%) and (2) non-insulin treatment and tertiles of daily insulin use. We found that 161 (36%) patients achieved the target HbA1c level. Patients with HbA1c ≥53 mmol/mol had a longer duration of diabetes (13 [8-20] vs 9 [4-14] years; P < .001) and more frequently were insulin-users (76% vs 41%, P < .001). Patients in the highest tertile of insulin use had a higher body mass index than those in the lowest tertile (35.8 ± 5.5 vs 29.8 ± 5.5 kg/m2 ; P < .001). Achievement of target HbA1c is low in this type 2 diabetes population. High resistance to pharmacological treatment, paralleled with high body mass index, illustrates that increasing insulin sensitivity through lifestyle intervention is the best opportunity to improve HbA1c target achievement in this real-life population.