P2485Cardiac abnormalities and vascular damage in young adults with type 1 diabetes mellitus: incidence and associations with kidney dysfunction

Background

In contrast to type 2 diabetes mellitus (DM), cardiac and vascular abnormalities in type 1 DM (T1DM) are not well investigated. We aimed to evaluate occurrence of cardiac remodeling, arterial stiffness and blood pressure (BP) phenotypes in T1DM patients.

Methods

The cross-sectional study consecutively included T1DM patients 18–44 y.o. without known CVD, in whom 24-hour monitoring of peripheral and central BP (ABPM) with BPLab Vasotens, applanation tonometry and conventional and speckle tracking echo were performed. BP phenotypes were determined according to current guidelines, PWV and CBP - according to individual reference values. Presence of systolic dysfunction was defined as global longitudinal strain (GLS) <20%, left ventricular hypertrophy (LVH) as LV myocardial mass index (LVMI) >95/>115 g/m2 for women/men, LV remodeling (LVR) as RWT ≥0.43. P<0.05 was considered significant.

Results

A total of 125 patients with T1DM (mean age 29,2±7,6 years, 60% male, median duration of DM 6,9 [2; 11] years, HbA1c 9.9 [6; 12] %, mean BMI 23±3 kg/m2, smoking 39%, median GFR 100 [86; 117] ml/min/1.73 m2, GFR <60 ml/min/1.73 m2 – in 8.8%, median albuminuria 19 [8; 24] mg/g (moderate and high albuminuria in 14.6% and 2.2%) were investigated.

According to office BP and ABPM hypertension (HTN) was diagnosed in 28% patients (true and masked in 4.8 and 23.2%, respectively) and true normotension in 72%.

Isolated nocturnal HTN was observed in 14.4%. Majority of the patients were dippers (51.2%), non-dippers and night-peakers profiles were registered in and 43.2% and 5.6%, respectively. Central SBP and PWV elevation were observed in 17.6% and 57.6% (PWV >10 m/s - only in 2.4%). Cardiac abnormalities were revealed in 72.4% of patients: GLS<20%, LVH, LVR and diastolic dysfunction (DD) in 71.2, 12, 39.2 and 16.8% patients, respectively. Isolated GLS <20% was detected in 30%, combination of GLS<20% with LVH (or LVR) and DD in 47.2%.

Patients with vs without HTN were characterized by higher PWV (7.8±1.5 vs 6.9±1.2, p<0.001), LVMI (89.9 [75; 96] vs 71.5 [64; 77] p<0.001), incidence of DD (29.6 vs 12.2%, p=0.03), LVH (28 vs 6%, p=0.002), trend towards higher rate of central SBP increase (32.7% vs 17.4%, p=0.08), lower incidence of LVR (26 vs 44%, p=0.002) and similar GLS (p=0.16).

Groups with vs without nocturnal HTN did not differ by PWV, central SBP, GLS and LVMI. PWV increase was associated only with higher LVMI (88.2 [69; 95] vs 77.6 [68; 83], p=0.042).

Correlations (p<0.05) with albuminuria were observed for GLS (r=−0.26), DD (r=0.22) and non-dipping state (r=−0.34). GFR correlated (p<0.05) with GLS (r=−0.32) and PWV (r=−0.32).

Conclusion

Incidence of prognostically unfavourable phenotypes of HTN, cardiac remodeling and arterial stiffness (even in patients without HTN) were relatively high in T1DM population. GLS and non-dipping state correlated with albuminuria, GLS and PWV with GFR

Enhancements in specimen preparation of Cu(In,Ga)(S,Se)2 thin films

When producing slices from Cu(In,Ga)(S,Se)(2) thin films for solar cells by use of a focused ion beam (FIB), agglomerates form on the Cu(In,Ga)(S,Se)(2) surfaces, which deteriorate substantially the imaging and analysis in scanning electron microscopy. Similar problems are also experienced when depth-profiling Cu(In,Ga)(S,Se)(2) thin films by means of glow-discharge or secondary ion mass spectrometry. The present work shows that the agglomerates are composed of (mainly) Cu, and that their formation may be impeded considerably by either cooling of the sample or by use of reactive gases during the ion-beam sputtering. The introduction of XeF(2) during FIB slicing resulted in excellent images, in which the microstructures of most layers in the Cu(In,Ga)(S,Se)(2) thin film stack are visible, including the microstructure of the 20 nm thin MoSe(2) layer. Acquisition of high-quality two-dimensional and also three-dimensional electron backscatter diffraction data was possible. The present work gives a basis for enhanced SEM imaging and analysis not only in the case of Cu(In,Ga)(S,Se)(2) thin films but also when dealing with further material systems exhibiting similar formations of agglomerates.

Comprehensive comparison of various techniques for the analysis of elemental distributions in thin films

The present work shows results on elemental distribution analyses in Cu(In,Ga)Se2 thin films for solar cells performed by use of wavelength-dispersive and energy-dispersive X-ray spectrometry (EDX) in a scanning electron microscope, EDX in a transmission electron microscope, X-ray photoelectron, angle-dependent soft X-ray emission, secondary ion-mass (SIMS), time-of-flight SIMS, sputtered neutral mass, glow-discharge optical emission and glow-discharge mass, Auger electron, and Rutherford backscattering spectrometry, by use of scanning Auger electron microscopy, Raman depth profiling, and Raman mapping, as well as by use of elastic recoil detection analysis, grazing-incidence X-ray and electron backscatter diffraction, and grazing-incidence X-ray fluorescence analysis. The Cu(In,Ga)Se2 thin films used for the present comparison were produced during the same identical deposition run and exhibit thicknesses of about 2 μm. The analysis techniques were compared with respect to their spatial and depth resolutions, measuring speeds, availabilities, and detection limits.