As recently claimed, TSH-suppressive therapy with L-T4 may have adverse effects on the heart, but these results have not been consistently confirmed. We assessed cardiac function by clinical, echocardiographic, and ergometabolic criteria in 19 patients (16 women and 3 men) receiving long term L-T4 at a fixed daily dose ranging from 1.8-4.0 microg/kg. The results showed significant alterations in several cardiac parameters suggestive of subclinical hyperthyroidism. In particular, intraventricular septum thickness (10.0+/-1.4 vs. 8.1+/-1.1 mm), left ventricular posterior wall thickness (9.4 1.5 vs. 8.1+/-1.1 mm), end-diastolic dimension (47+/-4 vs. 44+/-3 mm), and left ventricular mass index (102+/-15 vs. 75+/-15 g/m2) were significantly increased compared to values in age- and sex-matched euthyroid controls. Exercise tolerance (expressed as maximal tolerated workload; 102+/-14 vs. 117+/-12 watts), maximal VO2 achieved at peak exercise (maximum VO2, 17.3+/-3.3 vs. 21.9+/-2.5 mL/min x kg), and anaerobic threshold (expressed as a percentage of VO2max, 46.5+/-8.4 vs. 56.2+/-6.6) were significantly reduced in L-T4-treated patients. The L-T4 dose was then reduced to the minimal amount able to keep the serum TSH concentration at 0.1 mU/L or less in 7 patients who were reevaluated 6 months after the initial study. This individual tailoring of the TSH-suppressive L-T4 dose was in all cases associated with normalization of all echocardiographic and ergometabolic parameters. In conclusion, our findings show that abnormalities of heart morphology associated with impaired exercise performance occur as a consequence of long term therapy with fixed TSH-suppressive doses of L-T4, but that these abnormalities improve or disappear after careful tailoring of TSH-suppressive therapy.

BackgroundMetformin (MET) therapy exerts positive effects improving glucose tolerance and preventing the evolution toward diabetes in insulin resistant patients. It has been shown that adding MET to exercise training does not improve insulin sensitivity. The aim of this study was to determine the effect of MET and exercise training alone or in combination on maximal aerobic capacity and, as a secondary end-point on quality of life indexes in individuals with insulin resistance.Methods75 insulin resistant patients were enrolled and subsequently assigned to MET (M), MET with exercise training (MEx), and exercise training alone (Ex). 12-weeks of supervised exercise-training program was carried out in both Ex and MEx groups. Cardiopulmonary exercise test and SF-36 to evaluate Health-Related Quality of Life (HRQoL) was performed at basal and after 12-weeks of treatment.ResultsCardiopulmonary exercise test showed a significant increase of peak VO2 in Ex and MEx whereas M showed no improvement of peak VO2 (∆ VO2 [CI 95%] Ex +0.26 [0.47 to 0.05] l/min; ∆ VO2 MEx +0.19 [0.33 to 0.05] l/min; ∆ VO2 M -0.09 [-0.03 to -0.15] l/min; M vs E p < 0.01; M vs MEx p < 0.01; MEx vs Ex p = ns). SF-36 highlighted a significant increase in general QoL index in the MEx (58.3 ± 19 vs 77.3 ± 16; p < 0.01) and Ex (62.1 ± 17 vs 73.7 ± 12; p < 0.005) groups.ConclusionsWe evidenced that cardiopulmonary negative effects showed by MET therapy may be counterbalanced with the combination of exercise training. Given that exercise training associated with MET produced similar effects to exercise training alone in terms of maximal aerobic capacity and HRQoL, programmed exercise training remains the first choice therapy in insulin resistant patients.

Contrast-enhanced transthoracic echo Doppler with the harmonic mode is a feasible and promising technique for assessing CFR in a totally noninvasive way.

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Symmetric batteries, in which the same active material is used for the positive and the negative electrode, simplifying the manufacture process and reducing the fabrication cost, have attracted extensive interest for large-scale stationary energy storage. In this paper, we propose a symmetric battery based on titanium hexacyanoferrate (TiHCF) with two well-separated redox peaks of Fe3+/Fe2+ and Ti4+/Ti3+ and tested it in aqueous Na-ion/ K-ion/Mg-ion electrolytes. The result shows that all the symmetric batteries exhibit a voltage plateau centered at around 0.6 V, with discharge capacity around 30 mAhg−1 at C/5. Compared to a Mg-ion electrolyte, the TiHCF symmetric batteries in Na-ion and K-ion electrolytes have better stability. The calculated diffusion coefficient of Na+, K+, and Mg2+ are in the same order of magnitude, which indicates that the three-dimensional ionic channels and interstices in the lattice of TiHCF are large enough for an efficient Na+, K+ and Mg2+ insertion and extraction.