Obesity and cardiovascular risk

Obesity has assumed epidemic proportions and is expected to decrease the life expectancy of current and future generations by its cardiovascular complications and other associated chronic diseases. Recognizing the gravity of this trend, the American Heart Association recently identified obesity as an independent and important modifiable risk factor for cardiovascular disease. Obesity is known to cluster with other cardiovascular and metabolic risk factors constituting the cardiometabolic syndrome. The pathophysiogic link between obesity and cardiovascular disease is complex and involves multiple metabolic and inflammatory risk factors. In an attempt to better elucidate this major public health problem, this article reviews obesity as an epidemic, the structural and functional changes in the cardiovascular system as a result of obesity, and the pathophysiology of obesity-related cardiomyopathy. The sheer magnitude of the problem of obesity with its immense cardiovascular consequences warrants immediate intervention.     

Aldosterone and cardiovascular risk

Through its classic effects on sodium and potassium homeostasis, aldosterone, when produced in excess, is associated with the development of hypertension and hence with higher cardiovascular and renal risk. In recent years, experimental and epidemiologic data have suggested that aldosterone also may be linked to high cardiovascular risk independently of its effects on blood pressure. Thus, aldosterone has been associated with obesity and metabolic syndrome in selected populations, and these associations may further contribute to the higher cardiovascular risk of subjects with elevated aldosterone levels. Moreover, aldosterone has been reported to promote inflammation, oxidative stress, and fibrosis in a number of tissues. Clinical evidence indicates that patients with primary hyperaldosteronism have a higher risk of developing cardiovascular and renal complications than patients with essential hypertension who have the same level of blood pressure. Aldosterone receptor blockade has been shown to lower cardiovascular mortality after myocardial infarction and in patients with congestive heart failure. Some studies have also demonstrated that aldosterone blockade could have a favorable impact on the progression of renal disease. However, prospective interventional trials are needed to further evaluate the impact of blockade of aldosterone on cardiovascular risk.     

Hyperglycaemia and cardiovascular risk

Cardiovascular diseases represent, today, the principal cause of mortality in the general population, especially in subjects with type 2 diabetes mellitus. In these patients the risk of death from cardiovascular diseases is equal to that of non-diabetic subjects with a previous episode of myocardial infarction. Many factors concur to determine such high risk. Hyperglycaemia contributes to the increase in morbidity and cardiovascular mortality associated with diabetes mellitus. Hyperglycaemia acts as a multiplier of cardiovascular risk due to frequent association of multiple risk factors in diabetic patients. Therefore, effective treatment requires a more complete assessment of quantitative and qualitative aspects of glycemic control as well as all components of the diabetic syndrome or, more commonly, metabolic syndrome.     

Testosterone and cardiovascular risk

Cardiovascular (CV) disease is one of the most common causes of death in the western populations and, nowadays, its incidence is increasing even in the developing countries; although CV disease affects both sexes, it is more frequent in males in whom it shortens the average life expectancy. In this regard, this difference has been wrongly attributed for many years to the negative effects of testosterone (T); however, nowadays, a large amount of evidence suggests that this hormone may have protective effects on the CV system and that, indeed, the low levels of T could be associated with an increased CV risk and with an augmentation of morbidity and mortality in males. Such an aspect gains great relevance in light of the consideration that T decrease, besides occurring as a consequence of rare pathological conditions, can often take place with natural aging, causing a state of “male menopause”, also called late-onset hypogonadism. In this review, we aimed to summarize the present state of the art concerning the association between T deficit and CV disease by analyzing the protective role of T on CV system and the relationship of this hormonal lack with metabolic syndrome, CV morbidity and mortality, and with the CV complications, such as ischemic heart disease, heart failure and stroke, that frequently occur in T deficiency.     

Glucose and cardiovascular risk

The American Diabetes Association and the World Health Organisation have recently redefined the spectrum of abnormal glucose tolerance. The criteria for diabetes mellitus were sharpened and impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) were classified as intermediate stages between normal glucose homeostasis and diabetes, based on fasting and challenged glucose levels, respectively. Criteria were established for 'the metabolic syndrome', as a cluster of cardiovascular risk factors that frequently coincides with the abnormal glucose tolerance state. The extent to which the glucose level itself should be regarded as a cardiovascular risk factor is the subject of ongoing debate. Recent research suggests that cardiovascular risk is related to the plasma glucose level even in the normal range of glucose concentrations. The impact of glucose in relation to cardiovascular events is discussed in this review.     

Chemokines and cardiovascular risk

Based on the importance of inflammation in atherogenesis, recent work has focused on whether plasma markers of inflammation can noninvasively diagnose and prognosticate atherosclerotic disorders. Although several studies support an important pathogenic role of chemokines in atherosclerosis, potentially representing attractive therapeutic targets in atherosclerotic disorders, this does not necessarily mean that chemokines are suitable parameters for risk prediction. In fact, the ability to reflect upstream inflammatory activity, stable levels in individuals, and high stability of the actual protein (eg, long half-life and negligible circadian variation) are additional important criteria for an ideal biomarker in cardiovascular disease. Although plasma/serum levels of certain chemokines (eg, interleukin- 8/CXCL8 and monocyte chemoattractant protein-1/CCL2) have shown to be predictive for future cardiac events in some studies, their role as clinical biomarkers is unclear, and their ability to predict subclinical atherosclerosis has been disappointing. Further prospective studies, including a larger number of patients, are needed to make any firm conclusion. Based on the participation of several chemokines in atherogenesis, it is possible that in the future, combined measurements of multiple chemokines could reveal as a "signature of disease" that can serve as a highly accurate method to assess for the presence of atherosclerotic disease.     

Microalbuminuria and cardiovascular risk

Microalbuminuria is a marker for generalized vascular dysfunction. Its prevalence in United States and European general population surveys ranges from 6% to 10%. Increased risk for cardiovascular morbidity and mortality begins with albumin excretion rates that are well within normal limits. Although microalbuminuria interacts with the traditional cardiovascular risk factors, it has an independent relationship to renal and cardiovascular outcomes. For example, microalbuminuria doubles the risk for a cardiovascular event in patients with type 2 diabetes mellitus even after adjusting for the usual risk factors. Elevated rates of urinary albumin excretion predict target organ damage, notably renal disease, but are also related to left ventricular dysfunction, stroke, and myocardial infarction. Screening for microalbuminuria, which is recommended by several expert committees and associations, has become a readily accessible procedure. Screening can give clinicians prognostic information concerning cardiovascular risk and assist in guiding therapy. The goal of treatment is to prevent progression of, and even to reverse, microalbuminuria. Abundant evidence demonstrates that antihypertensive therapy is an important key to the control of urinary albumin excretion, and blockade of the renin-angiotensin system (with angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers) is the treatment of choice. These drugs have successfully halted or delayed the progression to nephropathy and have reversed elevated rates of albumin excretion to normal values, even when blood pressure reduction has been minimal.     

Rosiglitazone and cardiovascular risk

A meta-analysis of 42 clinical trials suggested that rosiglitazone, a widely used thiazolidinedione, was associated with a 43% greater risk of myocardial infarction (P = 0.03) and a 64% greater risk of cardiovascular death (P = 0.06). However, a number of criticisms have been raised that potentially undermine the conclusions of this analysis. In this article, we point out some of these limitations, summarize the currently available evidence concerning rosiglitazone and cardiovascular risk, share implications for drug safety evaluation, and offer practical recommendations to health care providers. We conclude that the data showing the increased risk for myocardial infarction and death from cardiovascular disease for diabetic patients taking rosiglitazone are inconclusive.     

中国心血管内科医师高血压情况和心血管病发病风险

目的 了解中国心血管内科医师高血压患病、治疗和控制情况,评估心血管内科医师心血管疾病发病的风险,为制定干预策略、促进人群健康提供依据.方法 对中国内地31个省、自治区、直辖市,共386家综合性医院心血管内科共4032名心血管内科医师进行高血压患病率、知晓率、治疗率和控制率的流行病学调查,并对冠心病和缺血性心血管疾病的发病风险进行评估.结果 我国心血管内科医师的高血压患病率为13.1%.心血管内科医师的高血压知晓率为81.7%,治疗率为69.6%,控制率44.6%.心血管内科医师55岁之前高血压患病率男性高于女性,55岁以后两性之间差异无统计学意义.高血压组Framinham冠心病风险量表的10年冠心病风险平均为0.08,非高血压组平均为0.03.国人10年缺血性心血管病风险量表的10年绝对风险高血压组平均为0.03,非高血压组平均为0.01.结论 中国心血管内科医师高血压的知晓率、治疗率、控制率均不够理想.患高血压医师的心血管疾病风险较高,有必要提倡其对血压情况的自我监测.

Abstract：

Objective To observe the prevalence, awareness, treatment and control rate of hypertension and to evaluate the 10-year absolute risk of coronary heart disease (CHD) and ischemic cardiovascular disease (ICVD) in Chinese cardiovascular physicians. Methods A total of 4032cardiovascular physicians (28 to 79 years old) from 386 hospitals in 31 provinces, autonomous regions and municipalities were randomly selected and received an epidemiologic survey of prevalence, awareness, and control of hypertension and evaluations of CHD and ICVD risk. Results The prevalence of hypertension in Chinese cardiovascular physicians was 13.1%. The awareness rate of hypertension in Chinese cardiovascular physicians was 81.7%. Hypertension treatment rate was 69. 6% and blood pressure control rate was 44. 6%. The prevalence of hypertension was higher in male physicians than in female physicians before the age of 55 years old. Ten-year absolute risk of CHD and ICVD was 0. 08 and 0. 03 in hypertensive physicians compared to 0. 03 and 0. 01 in non-hypertensive physicians. Conclusions The results show suboptimal awareness, treatment and control rate in Chinese cardiovascular physicians for their own hypertension status. Physicians suffering from hypertension face higher risk for cardiovascular disease. It is therefore necessary to improve the self-monitoring of blood pressure in Chinese cardiovascular physicians.     

Renin-angiotensin system and cardiovascular risk

The renin-angiotensin system is a major regulatory system of cardiovascular and renal function. Basic research has revealed exciting new aspects, which could lead to novel or modified therapeutic approaches. Renin-angiotensin system blockade exerts potent antiatherosclerotic effects, which are mediated by their antihypertensive, anti-inflammatory, antiproliferative, and oxidative stress lowering properties. Inhibitors of the system-ie, angiotensin converting enzyme inhibitors and angiotensin receptor blockers, are now first-line treatments for hypertensive target organ damage and progressive renal disease. Their effects are greater than expected by their ability to lower blood pressure alone. Angiotensin receptor blockers reduce the frequency of atrial fibrillation and stroke. Renin-angiotensin system blockade delays or avoids the onset of type 2 diabetes and prevents cardiovascular and renal events in diabetic patients. Thus, blockade of this system will remain a cornerstone of our strategies to reduce cardiovascular risk.