Effect of lifestyle intervention plus rosiglitazone or placebo therapy on left ventricular mass assessed with cardiovascular magnetic resonance in the metabolic syndrome

Metabolic syndrome: imaging features and clinical outcomes

Metabolic syndrome, which affects around a quarter of adults worldwide, is a group of metabolic abnormalities characterized mainly by insulin resistance and central adiposity. It is strongly correlated with cardiovascular and all-cause mortality. Early identification of the changes induced by metabolic syndrome in target organs and timely intervention (eg, weight reduction) can decrease morbidity and mortality. Imaging can monitor the main components of metabolic syndrome and identify early the development and progression of its sequelae in various organs. In this review, we discuss the imaging features across different modalities that can be used to evaluate changes due to metabolic syndrome, including fatty deposition in different organs, arterial stiffening, liver fibrosis, and cardiac dysfunction. Radiologists can play a vital role in recognizing and following these target organ injuries, which in turn can motivate lifestyle modification and therapeutic intervention.

Diagnostic imaging in the management of patients with metabolic syndrome

Metabolic syndrome (MetS) is the constellation of metabolic risk factors that might foster development of type 2 diabetes and cardiovascular disease. Abdominal obesity and insulin resistance play a prominent role among all metabolic traits of MetS. Because intervention including weight loss can reduce these morbidity and mortality in MetS, early detection of the severity and complications of MetS could be useful. Recent advances in imaging modalities have provided significant insight into the development and progression of abdominal obesity and insulin resistance, as well as target organ injuries. The purpose of this review is to summarize advances in diagnostic imaging modalities in MetS that can be applied for evaluating each components and target organs. This may help in early detection, monitoring target organ injury, and in turn developing novel therapeutic target to alleviate and avert them.

Does Thiazolidinedione therapy exacerbate fluid retention in congestive heart failure?

The ever-growing global burden of congestive heart failure (CHF) and type 2 diabetes mellitus (T2DM) as well as their co-existence necessitate that anti-diabetic pharmacotherapy will modulate the cardiovascular risk inherent to T2DM while complying with the accompanying restrictions imposed by CHF. The thiazolidinedione (TZD) family of peroxisome proliferator-activated receptor γ (PPARγ) agonists initially provided a promising therapeutic option in T2DM owing to anti-diabetic efficacy combined with pleiotropic beneficial cardiovascular effects. However, the utility of TZDs in T2DM has declined in the past decade, largely due to concomitant adverse effects of fluid retention and edema formation attributed to salt-retaining effects of PPARγ activation on the nephron. Presumably, the latter effects are potentially deleterious in the context of pre-existing fluid retention in CHF. However, despite a considerable body of evidence on mechanisms responsible for TZD-induced fluid retention suggesting that this class of drugs is rightfully prohibited from use in CHF patients, there is a paucity of experimental and clinical studies that investigate the effects of TZDs on salt and water homeostasis in the CHF setting. In an attempt to elucidate whether TZDs actually exacerbate the pre-existing fluid retention in CHF, our review summarizes the pathophysiology of fluid retention in CHF. Moreover, we thoroughly review the available data on TZD-induced fluid retention and proposed mechanisms in animals and patients. Finally, we will present recent studies challenging the common notion that TZDs worsen renal salt and water retention in CHF.

Inflammation increases plasma angiopoietin-like protein 4 in patients with the metabolic syndrome and type 2 diabetes

BACKGROUND

Angiopoietin-like protein 4 (ANGPTL4) inhibits lipoprotein lipase and associates with dyslipidemia. The expression of ANGPTL4 is regulated by free fatty acids (FFA) that activate lipid-sensing peroxisome proliferator-activated receptors (PPARs), but FFA can also activate pattern recognition receptors including Toll-like receptor 4 (TLR4) in macrophages.

OBJECTIVE

To assess whether systemic low-grade inflammation is a determinant for plasma ANGPTL4 levels in patients with the metabolic syndrome (MetS) and type 2 diabetes mellitus (T2DM).

DESIGN

We studied 335 male participants: healthy controls (Controls), patients with the MetS without inflammation (MetS-I) and with low-grade inflammation (MetS+I), and patients with T2DM. All patients without diabetes included in the present study were initially matched for waist circumference. In plasma, ANGPTL4, C reactive protein (CRP) and metabolic parameters were determined. Underlying mechanisms were examined using human macrophages in vitro.

RESULTS

As compared with Controls, plasma ANGPTL4 levels were increased in patients with MetS-I, MetS+I, and T2DM. Furthermore, ANGPTL4 was increased in T2DM compared with MetS-I. In fact, plasma CRP correlated positively with plasma ANGPTL4. In vitro studies showed that TLR 3/4 activation largely increased the expression and release of ANGPTL4 by macrophages.

CONCLUSIONS

Plasma ANGPTL4 levels in humans are predicted by CRP, a marker of inflammation, and ANGPTL4 expression by macrophages is increased by inflammatory stimuli.

Review of Journal of Cardiovascular Magnetic Resonance 2012

There were 90 articles published in the Journal of Cardiovascular Magnetic Resonance (JCMR) in 2012, which is an 8% increase in the number of articles since 2011. The quality of the submissions continues to increase. The editors are delighted to report that the 2011 JCMR Impact Factor (which is published in June 2012) has risen to 4.44, up from 3.72 for 2010 (as published in June 2011), a 20% increase. The 2011 impact factor means that the JCMR papers that were published in 2009 and 2010 were cited on average 4.44 times in 2011. The impact factor undergoes natural variation according to citation rates of papers in the 2 years following publication, and is significantly influenced by highly cited papers such as official reports. However, the progress of the journal's impact over the last 5 years has been impressive. Our acceptance rate is approximately 25%, and has been falling as the number of articles being submitted has been increasing. In accordance with Open-Access publishing, the JCMR articles go on-line as they are accepted with no collating of the articles into sections or special thematic issues. For this reason, the Editors have felt that it is useful once per calendar year to summarize the papers for the readership into broad areas of interest or theme, so that areas of interest can be reviewed in a single article in relation to each other and other recent JCMR articles. The papers are presented in broad themes and set in context with related literature and previously published JCMR papers to guide continuity of thought in the journal. We hope that you find the open-access system increases wider reading and citation of your papers, and that you will continue to send your quality manuscripts to JCMR for publication.

Cardiovascular characteristics in subjects with increasing levels of abnormal glucose regulation: the Strong Heart Study

OBJECTIVE

To evaluate whether impaired fasting glucose (IFG) or the combination of IFG and impaired glucose tolerance (IGT) is associated with progressive abnormalities of cardiac geometry and function.

RESEARCH DESIGN AND METHODS

We studied 562 nondiabetic (311 women), nonhypertensive participants of the second Strong Heart Study exam, without prevalent cardiovascular (CV) disease and with estimated glomerular filtration rate ≥60 mL/min/1.73 m(2) (age 46-65 years, 198 with isolated IFG [35%], and 132 with combined IFG and IGT [23%]). Anthropometric parameters, insulin resistance, fibrinogen, C-reactive protein (CRP), lipid profile, blood pressure (BP), and echocardiographic parameters were compared with 232 participants with normal glucose tolerance (NGT).

RESULTS

BMI, prevalence of central obesity, homeostatic model assessment index of insulin resistance, plasma triglycerides, fibrinogen, and CRP increased progressively across categories of glucose intolerance (P < 0.0001), with the IFG+IGT group having higher values than those with isolated IFG (0.05 < P < 0.0001). Compared with NGT, both IFG and IFG+IGT exhibited greater left ventricular (LV) mass (P < 0.0001) and lower Doppler early peak rapid filling velocity to peak atrial filling velocity ratio (P < 0.005), without differences in LV systolic function. The odds of LV hypertrophy (LV mass index >46.7 in women or >49.2 g/m(2.7) in men) was 3.5 in IFG participants (95% CI 0.68-17.76; P = NS) and 9.76 (2.03-46.79; P = 0.004) in IFG+IGT, compared with NGT, after adjustment for age, sex, heart rate, systolic BP, and waist circumference (WC). In the overall sample, LV mass index was associated with WC (P = 0.033), CRP (P = 0.027), and 2-h oral glucose tolerance test (P = 0.001) independently of confounders.

CONCLUSIONS

Cardiometabolic profile and markers of inflammation are more severely altered in men and women with both IFG and IGT compared with those with IFG alone. These individuals, in the absence of hypertension, have a 10-fold greater probability of preclinical CV disease (LV hypertrophy).

Review of Journal of Cardiovascular Magnetic Resonance 2011

There were 83 articles published in the Journal of Cardiovascular Magnetic Resonance (JCMR) in 2011, which is an 11% increase in the number of articles since 2010. The quality of the submissions continues to increase. The editors had been delighted with the 2010 JCMR Impact Factor of 4.33, although this fell modestly to 3.72 for 2011. The impact factor undergoes natural variation according to citation rates of papers in the 2 years following publication, and is significantly influenced by highly cited papers such as official reports. However, we remain very pleased with the progress of the journal's impact over the last 5 years. Our acceptance rate is approximately 25%, and has been falling as the number of articles being submitted has been increasing. In accordance with Open-Access publishing, the JCMR articles go on-line as they are accepted with no collating of the articles into sections or special thematic issues. For this reason, the Editors feel it is useful to summarize the papers for the readership into broad areas of interest or theme, which we feel would be useful, so that areas of interest from the previous year can be reviewed in a single article in relation to each other and other recent JCMR articles. The papers are presented in broad themes and set in context with related literature and previously published JCMR papers to guide continuity of thought in the journal. We hope that you find the open-access system increases wider reading and citation of your papers, and that you will continue to send your quality manuscripts to JCMR for publication.