Hyponatremia and takotsubo syndrome: a review of pathogenetic and clinical implications

Hyponatremia is a common electrolyte abnormality with important prognostic and therapeutic implications. It might exert detrimental effects on various organ systems including the central nervous system (CNS), bone, and heart along with its potential association with poor quality of life. These adverse effects might be largely mediated through a variety of mechanisms including osmotic stress, dysfunctional transmembrane exchangers, and enhanced oxidative stress.Interestingly, hyponatremia might also have an important association with takotsubo syndrome (TTS) that has been universally considered as a reversible form of cardiomyopathy usually emerging in response to various stressors. In this context, severe hyponatremia was previously reported to serve as a direct trigger of TTS evolution largely through its potential impact on CNS and heart. However, pathogenetic and clinical implications of hyponatremia still need to be thoroughly evaluated in patients with TTS. This paper aims to analyze the clinical features of published cases with TTS primarily triggered by hyponatremia and also aims to discuss the association between hyponatremia and TTS from a broader perspective.

The role of eNOS gene polymorphisms on contrast induced nephropathy development in chronic kidney disease patients

INTRODUCTION

Contrast nephropathy is a result of contrast media given through intravascular routes. Nitric oxide gene polymorphisms may alter the hemodynamic stability resulting in medullary ischemia Nitric oxide gene polymorphisms may have an enhancing role in contrast media related renal injury. The aim of this study was to investigate the role of eNOS intron 4a/b, T786C, and G894T gene polymorphisms on contrast-nephropathy risk.

METHODS

Ninety-four chronic kidney disease patients with contrast nephropathy and 120 chronic kidney disease patients without contrast nephropathy were included. DNA isolation was performed and specific regions of DNA for eNOS G894T, T786C, and intron 4a/b genes were amplified by polymerase chain reaction technique.

RESULTS

TT polymorphism of T786C gene and GG polymorphism of G894T gene were detected to be possibly protective from contrast induced nephropathy.

CONCLUSION

Endothelial nitric oxide synthase G894T gene polymorphisms, older age, and presence of diabetes mellitus may influence contrast nephropathy development.

Cardiac Biomarkers in the Setting of Asthma Exacerbations: a Review of Clinical Implications and Practical Considerations

PURPOSE OF REVIEW

The present paper aims to highlight clinical implications of elevated cardiac biomarkers and associated myocardial dysfunction in a variety of cardiac and non-cardiac scenarios in patients with an asthma exacerbation, and to propose a basic algorithm for cardiovascular evaluation and triage (and hence, for further management) of these patients primarily based on evaluation of cardiac biomarkers along with basic diagnostic modalities and specific cardiac symptoms in the hospital setting.

RECENT FINDINGS

Elevation of cardiac biomarkers in the setting of an asthma exacerbation mostly signifies a new-onset subclinical myocardial dysfunction/injury generally associated with certain asthma-related factors including acute hypoxemia and bronchodilator therapy, and usually has a limited prognostic value in these patients. On the other hand, elevation of these biomarkers in patients with an asthma exacerbation might also denote a variety of certain life-threatening cardiac or non-cardiac conditions associated with significant myocardial dysfunction (acute coronary syndromes (ACSs), sepsis, etc.) that might be masked by the rampant course of the asthma exacerbation, and hence, might possibly go undetected potentially aggravating the prognosis in a portion of these patients. In patients with an asthma exacerbation, it seems imperative to timely diagnose and manage emerging diverse clinical conditions particularly through the guidance of cardiac biomarkers and associated myocardial dysfunction patterns in an effort to improve overall prognosis in these patients.

High-intensity interval training acutely alters plasma adipokine levels in young overweight/obese women

The aim of this study was to investigate the plasma adipokine responses to high-intensity interval training (HIT) in overweight/obese women. Twelve women (age 21.7 ± 3.8 years) completed a 19 days of HIT comprising six session of 4-6 repeats of a Wingate test (0.065 kg load/kg). Plasma adipokine levels were measured before exercise, and at 5 and 90 min after exercise on the first and the last training days. Adiponectin was higher at 5 min than 90 min post-exercise (11.7 ± 7.3 and 10.5 ± 5.8 ng/ml; p = .01) in the first exercise day. Leptin decreased 5 min after exercise (23.6 ± 13.2 vs. baseline 27.8 ± 14.4 ng/ml; p < .01) and remained depressed following 90 min (p < .01). The changes in adiponectin and leptin concentrations were similar on the first and last exercise days. No consistent effect was found on resistin concentration. Future studies are required to disclose the functional consequences of these alterations in plasma adipokine levels.

The alteration of NTproCNP plasma levels following anaerobic exercise in physically active young men

Objective:

Amino-terminal propeptide of C-type natriuretic peptide (NTproCNP) is a synthesis product of C-type natriuretic peptide (CNP). In this study, plasma levels of NTproCNP were compared before and after exercise in healthy young subjects who are physically active (PA) or not physically active (NPA).

Methods:

The study was carried on PA group (n=10) who defined the exercise duration more than 2.5 hours per week for at least one year and NPA group (n=10) whose exercise duration was lower than 1.5 hours per week. The level of maximal oxygen consumption was determined. Wingate exercise test was applied on the following day. Plasma NTproCNP levels were measured before the exercise and at the 1^st, 5^th and 30^th minute after the exercise.

Results:

Exercise duration of physically active group was reported as 11.3±5.0 hours per week. Basal NTproCNP levels of the groups were found to be comparable. NTproCNP levels in the 5^th minute (0.93±0.23 pmol/L; p<0.05) and in the 30^th minute (0.77±0.21 pmol/L p<0.05) after exercise were higher than the levels before exercise (0.64±0.29 pmol/L) in PA group. Additionally, the plasma levels of NTproCNP after 5^th minute of exercise were higher in PA group (0.93±0.23 pmol/L) than NPA group (0.74±0.16 pmol/L, p<0.05).

Conclusion:

Being physically active may be a fact affecting the secretion of CNP, which plays a protective role in endothelium, following exercise.

Investigation of insulin resistance gene polymorphisms in patients with differentiated thyroid cancer

We aimed to investigate insulin receptor substrate-1 (IRS-1), insulin receptor substrate-2 (IRS-2), insulin-like growth factor binding protein-3 (IGFBP-3) genotypes, which are thought to be involved in the pathogenesis of many solid tumors and have thus far not been studied in patients with differentiated thyroid cancer (DTC). The study consisted of 93 patients diagnosed with DTC (79 females, 14 males) and 111 healthy control subjects (63 females, 48 males). The anthropometric measurements, lipid profiles, thyroid function tests and homeostatic model assessment (HOMA) as an indicator of insulin resistance (IR) of all patients were recorded. In addition IRS-1, IRS-2 and IGFBP-3 gene polymorphisms were determined by using polymerase chain reaction and restriction fragment length polymorphism. Hardy-Weinberg equilibrium was tested for each gene polymorphisms, and genetic effects were evaluated by the Chi Square test and multiple logistic regression. Homeostasis model assessment of insulin resistance (HOMA-IR), body mass index, waist circumference and serum total cholesterol levels were significantly higher in patients with DTC than in the control group. There was no difference between the two groups with respect to IRS-1, IRS-2 and IGFBP-3 gene polymorphisms. In addition, these gene polymorphisms were found to have no effect on lymph node metastases or tumor staging. While, obesity and increased HOMA-IR may be risk factors in DTC development, we suggest that IRS-1, IRS-2 and IGFBP-3 gene polymorphisms do not play an important role in pathogenesis of DTC.