[18F]FDG and [18F]NaF as PET markers of systemic atherosclerosis progression: A longitudinal descriptive imaging study in patients with type 2 diabetes mellitus.

BACKGROUND: While [18F]-fluordeoxyglucose ([18F]FDG) uptake is associated with arterial inflammation, [18F]-sodium fluoride ([18F]NaF) is a marker for arterial micro-calcification. We aimed to investigate the prospective correlation between both PET markers over time and whether they are prospectively ([18F]FDG) and retrospectively ([18F]NaF) related to progression of systemic arterial disease in a longitudinal study in patients with type 2 diabetes mellitus (T2DM). METHODS: Baseline [18F]FDG PET/Low Dose (LD) Computed Tomography (CT) scans of ten patients with early T2DM without cardiovascular history (70% men, median age 63 years) were compared with five-year follow-up [18F]NaF/LDCT scans. Systemic activity was expressed as mean target-to-background ratio (meanTBR) by dividing the maximal standardized uptake value (SUVmax) of ten arteries by SUVmean of the caval vein. CT-assessed macro-calcifications were scored visually and expressed as calcified plaque (CP) score. Arterial stiffness was assessed with carotid-femoral pulse wave velocity (PWV). Five-year changes were expressed absolutely with delta (Δ) and relatively with %change. RESULTS: Baseline meanTBR[18F]FDG was strongly correlated with five-year follow-up meanTBR[18F]NaF (r = 0.709, P = .022). meanTBR[18F]NaF correlated positively with ΔCPscore, CPscore at baseline, and follow-up (r = 0.845, P = .002 and r = 0.855, P = .002, respectively), but not with %change in CPscore and PWV. CONCLUSION: This proof-of-concept study demonstrated that systemic arterial inflammation is an important pathogenetic factor in systemic arterial micro-calcification development.

Comparison of urine collection methods for albuminuria assessment in young children.

Cotton wool or pantyliners placed in a diaper can be used as urine collection devices for albuminuria measurements in young, not continent children. We tested a new collection method (PeeSpot(R)) for its analytical performance, and compared it with the pantyliner technique. Eighty-one urine samples with a wide range of albuminuria were pipetted on the pantyliner and PeeSpot in duplicate. These were incubated for 3h at 37°C (simulating the time a toddler wears a diaper), and subsequently 72h at room temperature (simulating transport to a central laboratory). Urine was extracted by centrifugation and albumin concentration (UAc) was measured. UAC measured by the two methods was compared with UAC in an unprocessed reference aliquot stored for 75h at 4°C. Bias (mean percentage UAC difference between test and reference), precision (interquartile range of the UAC difference) and accuracy (proportion of samples within 30% of reference UAC) were calculated. Median UAC in the reference aliquot was 66.0mg/L [IQR 25.0-211.0], pantyliner 32.0mg/L [4.7-165.0; P<0.001 vs reference], and PeeSpot 61.0mg/L [27.0-216.0; P=0.84 vs reference]. Bias, precision and accuracy in pantyliner were -34.2%, 31.3mg/L and 48.1%; in PeeSpot 3.3%, 5.0mg/L and 96.3%. Passing-Bablok regression and Bland-Altman plot showed an underestimation for the pantyliner but not for the PeeSpot. The PeeSpot is an accurate and precise tool for collecting urine for albumin measurement in young children and should be preferred over the alternative cotton wool collection technique.

Dapagliflozin reduces albuminuria in patients with diabetes and hypertension receiving renin-angiotensin blockers.

AIMS: To characterize the effect of dapagliflozin on albuminuria and estimated glomerular filtration rate (eGFR) and to determine whether effects on albuminuria were mediated through changes in glycated haemoblogin (HbA1c), systolic blood pressure (SBP), body weight or eGFR. METHODS: We conducted a post hoc analysis of data pooled from two phase III clinical trials in hypertensive patients with type 2 diabetes (T2DM) on stable angiotensin-converting enzyme inhibitor or angiotensin receptor blocker therapy, randomly assigned to dapagliflozin 10 mg/day or matched placebo. This analysis included only patients with microalbuminuria or macroalbuminuria at baseline. RESULTS: Patients were randomized to receive dapagliflozin 10 mg (n = 167) or placebo (n = 189). Dapagliflozin resulted in greater 12-week reductions in albuminuria compared with placebo: -33.2% [95% confidence interval (CI) -45.4, -18.2]. The reduction in albuminuria was also present after adjusting for age, sex and changes in HbA1c, SBP, body weight and eGFR: -23.5% (95% CI -37.6, -6.3). There was a decrease in eGFR with dapagliflozin versus placebo that was readily reversed 1 week after last dose. No serious renal-related adverse events were observed in any group. CONCLUSIONS: Dapagliflozin was effective in lowering albuminuria in patients with T2DM and hypertension using renin-angiotensin system blockade therapy. Reductions in albuminuria were still present after adjusting for changes in HbA1c, SBP, body weight and eGFR. Dapagliflozin-induced improvements in glycaemic control and reductions in SBP, coupled with other potentially beneficial renal effects, may lead to a reduced long-term renal and cardiovascular risk.

Is a reduction in albuminuria associated with renal and cardiovascular protection? A post hoc analysis of the ALTITUDE trial.

AIMS: To investigate whether the degree of albuminuria reduction observed in the ALTITUDE trial is associated with renal and cardiovascular protection, and secondly, whether the reduction in albuminuria was too small to afford clinical benefit. METHODS: In a post hoc analysis of the ALTITUDE trial in 8561 patients with type 2 diabetes and chronic kidney disease or cardiovascular disease we examined the effect of albuminuria changes at 6 months on renal and cardiovascular outcomes using Cox proportional hazard regression. RESULTS: The median change in albuminuria in the first 6 months in the aliskiren arm of the trial was -12% (25th to 75th percentile: -48.7_to_ +41.9%) and 0.0% (25th to 75th percentile: -40.2_to_55%) in the placebo arm. Changes in albuminuria in the first 6 months were linearly associated with renal and cardiovascular endpoints: a >30% reduction in albuminuria in the first 6 months was associated with a 62% reduction in renal risk and a 25% reduction in cardiovascular risk compared with an increase in albuminuria. The association between changes at 6 months in albuminuria and renal or cardiovascular endpoints was similar in the two treatment groups (p for interaction >0.1 for both endpoints). CONCLUSIONS: The addition of aliskiren to angiotensin-converting enzyme inhibitor/angiotensin receptor blocker therapy resulted in albuminuria changes that were associated with renal and cardiovascular risk changes. This did not translate into renal or cardiovascular protection because the overall reduction in albuminuria in the aliskiren arm was too small and nearly similar to that in the placebo arm.