Heart failure accompanied by sick euthyroid syndrome and exercise training

Thyroxine increases Serca2 and Ryr2 gene expression in heart failure rats with euthyroid sick syndrome

OBJECTIVE

The current study was aimed at analyzing sarcoplasmic reticulum Ca2+ ATPase (Serca2) and ryanodine receptor type 2 (Ryr2) gene expression in rats subjected to surgery that induced HF and were subsequently treated with T4 using physiological doses.

MATERIALS AND METHODS

HF was induced in 18 male Wistar rats by clipping the ascending thoracic aorta to generate aortic stenosis (HFS group), while the control group (9-sham) underwent thoracotomy. After 21 weeks, the HFS group was subdivided into two subgroups. One group (9 Wistar rats) with HF received 1.0 µg of T4/100 g of body weight for five consecutive days (HFS/T4); the other group (9 Wistar rats) received isotonic saline solution (HFS/S). The animals were sacrificed after this treatment and examined for signs of HF. Samples from the left ventricles of these animals were analyzed by RT-qPCR for the expression of Serca2 and Ryr2 genes.

RESULTS

Rats with HF developed euthyroid sick syndrome (ESS) and treatment with T4 restored the T3 values to the Sham level and increased Serca2 and Ryr2 gene expression, thereby demonstrating a possible benefit of T4 treatment for heart function in ESS associated with HF.

CONCLUSION

The T4 treatment can potentially normalize the levels of T3 as well elevated Serca2 and Ryr2 gene expression in the myocardium in heart failure rats with euthyroid sick syndrome.

[Comparison of the changes of thyroid hormones after video-assisted thoracoscopic surgery and conventional thoracotomy in patients with non-small cell lung cancer]

BACKGROUND AND OBJECTIVE

Video-assisted thoracoscopic surgery (VATS) is the representative thoracic minimally invasive surgery. Compared with traditional open surgery (TOS), VATS has an advantage of less invasiveness, quicker recovery and milder postoperative pain. The aim of this study is to compare the influences of VATS and conventional thoracotomic lobectomy on thyroid hormones in treatment for non-small cell lung cancer (NSCLC).

METHODS

From Oct. 2010 to Aug. 2012, 44 consecutive patients with NSCLC were recruited and divided into two groups: VATS group (25 patients) and TOS group (19 patients). All the patients were drawn blood to measure the plasma levels of free T3, free T4, reverse T3 and TSH on the morning of the day before surgery, the postoperative day (POD)1, POD2, POD3 and POD7. We described the perioperative variation trend of the thyroid hormones and compared the differences between VATS group and TOS group.

RESULTS

There were no differences of thyroid hormone levels between the two groups before surgery. After surgery, the levels of FT3 and TSH were first dropped, then elevated and reached the lowest level on POD3 and POD1 separately. On POD7, they regained the before-surgery levels in VATS group while FT3 level was still significantly lower in TOS group (P=0.032). The FT4 and rT3 levels were first elevated, and then dropped after surgery. They both reached the peak concentrations on POD2, and rT3 levels of TOS group were significantly higher than those of VATS group on POD1, POD2 and POD3 (P<0.05). The changes of FT3 and rT3 levels were beyond normal ranges while changes of FT4 and TSH levels were within normal ranges. When variation trend of all the thyroid hormones were compared between the two groups, only rT3 level was found to have significant statistical differences (F=7.557, P=0.009).

CONCLUSIONS

All NSCLC patients after lobectomy have Euthyroid sick syndrome (ESS). Compared with traditional thoracotomy, VATS surgery has smaller influence on perioperative thyroid hormones and demonstrates a weaker acute stress reaction, which can benefit postoperative recovery of NSCLC patients.

Nonthyroidal illness and the cardiorenal syndrome

The cardiorenal syndrome represents a final common pathway for renal and congestive heart failure and heralds a poor prognosis. Factors that link the failing heart and the failing kidneys--the so-called cardiorenal connectors--are, therefore, of clinical and therapeutic interest. Alterations in the levels and function of thyroid hormones that fit the spectrum of nonthyroidal illnesses could be considered to be cardiorenal connectors as both renal failure and heart failure progress with the development of nonthyroidal illness. In addition, circumstantial evidence suggests that nonthyroidal illness can induce deterioration in the function of the heart and the kidneys via multiple pathways. As a consequence, these reciprocal associations could result in a vicious cycle of deterioration that likely contributes to increased mortality. In this Review, we describe the evidence for a pathophysiological role of nonthyroidal illness in the cardiorenal syndrome. We also discuss the available data from studies that have investigated the efficacy of thyroid hormone replacement therapy in patients with renal failure and the rationale for interventional trials to examine the effects of normalization of the thyroid hormone profile in patients with renal failure and congestive heart failure.

Myocardial protection in man--from research concept to clinical practice

Myocardial protection aims at preventing myocardial tissue loss: (a) In the acute stage, i.e., during primary angioplasty in acute myocardial infarction. In this setup, the attenuation of reperfusion injury is the main target. As a "mechanical" means, post-conditioning has already been tried in man with encouraging results. Pharmacologic interventions that could be of promise are statins, insulin, peptide hormones, including erythropoietin, fibroblast growth factor, and many others. (b) The patient with chronic coronary artery disease offers another paradigm, with the target of avoidance of further myocyte loss through apoptosis and inflammation. Various pharmacologic agents may prove useful in this context, together with exercise and "mechanical" improvement of cardiac function with attenuation of myocardial stretch, which by itself is a noxious influence. A continuous effort toward acute and chronically preserving myocardial integrity is a concept concerning both the researcher and the clinician.