Реферирование научной литературы по специальности. Английский язык. Учебное пособие

among those with class I obesity. There were few significant differences in these variables ac-cording to weight category among female participants, but all the differences remained significant among male participants. As expected, overweight children and young adults had a lower risk of most risk factors than did those with class I obesity.

Discussion

Severe obesity in children and young adults is associated with a high prevalence of abnormal levels of cardiometabolic variables. A high prevalence of abnormal values for certain variables among children and young adults with class II or class III obesity may provide important information beyond that identified with the use of standard obesity classifications, especially for boys and young men. The greater prevalence among participants 12 to 19 years of age is consistent with a previous report of the overall U.S. population of children and adolescents.20

Determination of the severity of obesity can help identify children and young adults who are at the greatest risk for the negative health effects associated with obesity. Current guidelines for screening do not differentiate among levels of obesity.7,21 Although the prevalence of abnormal values does not increase with obesity severity in

the case of all risk-factor variables, our findings of greater risks of abnormal HDL cholesterol level, systolic blood pressure, and glucose metabolism support the stratification of risk on the basis of the American Heart Association recommendations for classification of a higher level of obesity at 120% of the 95th per-

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centile.4 Our findings of the additional risk of abnormal triglyceride and glycated hemoglobin levels provide initial support for further risk stratification ac-cording to 140% of the 95th percentile.

The differences between male and female participants in our study are notable; severe obesity is associated with a higher prevalence of abnormal systolic blood pressure, triglyceride level, and glycated hemoglobin level among male participants than among female participants. It is possible that cardiometabolic risk factors develop earlier in boys than in girls. Alternatively, use of the same definitions of obesity for girls and boys may not determine equivalent risk. Our findings differ from those in other reports that used only standard definitions and showed minimal differences between boys and girls.22-24

Obesity during childhood increases the risk of long-term obesity,25,26 as well as the risks of substantial complications and death in adult-hood.27,28 Severe obesity during adolescence is associated with significantly higher risks of complications.29 Although prevention remains the primary goal in the management of obesity, focus has shifted to also identifying and treating complications associated with obesity.21 Classifying obesity into three categories provides a more fine-tuned approach to identifying patients with the greatest risk of potential complications and death.28,29 The treatment of childhood obesity is both recommended and effective30; however, intensive therapies, such as medically supervised meal replacement, pharmacologic treatment, and bariatric surgery, confer certain risks and are often costly. In addition, resources are too limited to appropriately ser-

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vice every child with obesity because most treatment clinics and programs are concentrated within tertiary-care pediatric hospitals.31 The confluence of risks and limited re-sources leaves many children with severe obesity and established cardiometabolic risk factors with-out effective options. The application of a more complex classification of obesity, if it identifies those at highest risk, may permit targeted interventions that could decrease morbidity and mortality and may also be cost-effective.

An accurate classification of children with marked obesity may improve the care of this patient population. The cost of treating complications related to obesity in adults has been estimated to be as high as $147 billion32 and will probably continue to rise.33 Children with obesity have higher outpatient health care expenditures than those with normal weight, with the increased costs believed to stem from the evaluation and treatment of coexisting conditions34; an improved estimation of risk that is based on obesity severity could lower the costs of evaluation without resulting in missed diagnoses of co-existing conditions. Children with severe obesity already have increased cardiometabolic risk, which may predict the early onset of serious diseases such as hypertension and diabetes.

As older adolescents transition to young adulthood, the recognition that teens with obesity have increased cardiometabolic risk will be important. Current treatment approaches are not as effective at higher levels of obesity than they are at lower levels of obesity.35-37 The findings in our study, when considered in the con-text of the negative effect that these risk factors have on subsequent quality of life,38 imply a need for the early identifica-

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tion of abnormal weight gain, primary and secondary prevention of obesity, and systemwide policy changes in the evaluation and management of obesity in health care.39

We examined a range of cardiometabolic risk-factor variables in a large and nationally representative population; however, our study has certain methodologic limitations. First, because this is a cross-sectional study, we could not show causality between obesity and risk factors. Second, although we used standard definitions of abnormal values for risk-factor variables, the cross-sectional design did not allow us to examine the effects of these abnormal values on future morbidity or mortality. Finally, the sample size was small in certain subgroups, particularly in the subgroup of young children, which resulted in wide confidence intervals and point estimates that should be interpreted with caution.

In conclusion, severe obesity in children and young adults is associated with a high prevalence of abnormal levels of cardiometabolic risk-factor variables. The prevalence of these abnormal values among children and young adults appears to be dependent on both age and severity of obesity. The inclusion of class II obesity in the standard obesity classification may assist in the identification of children who could be at the greatest risk for abnormal levels of HDL cholesterol, systolic blood pressure, and glucose, and the inclusion of class III obesity in the standard obesity classification may assist in the identification of those at the greatest risk for abnormal levels of triglycerides, diastolic blood pressure, and glycated hemoglobin.

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come increasingly established, reflecting the negative effect of systemic inflammation on the vascular system [1]. However, the evidence around this and subsequent impact on clinical guidelines varies between inflammatory conditions. It is well established that patients with rheumatoid arthritis (RA) have an excess risk of CVD morbidity and mortality [2], and this is reflected in UK clinical guidelines advocating annual screening for CVD risk factors in patients with RA to mitigate this excess risk [3, 4]. In contrast, though patients with ankylosing spondylitis (AS) and psoriatic arthritis (PsA) are also believed to be at an increased risk of CVD [5–7], results have shown a mixed profile. To date, most studies have been conducted in secondary care and are therefore more likely to reflect patients with more severe disease and who may be more likely to develop CVD. A lack of primary care research around the risk of AS and PsA populations developing CVD-related comorbidities makes management difficult for general practitioners (GP). In previous AS research, a Swedish registry cohort found significantly greater standardised morbid- ity-rate ratios (SMR) for ischaemic heart disease (IHD), hypertension and diabetes mellitus [8]. In a longitudinal primary care population from Wales, AS patients had similar rates of myocardial infarction (MI) and stroke as matched-controls, but hypertension was more prevalent [9]. A Dutch study found an increased prevalence of hypertension in patients with AS compared to the general population [6] and though a second Dutch study found female patients with AS to be at greater risk of developing myocardial infarction, male AS patients were not [10]. Regarding the relationship between PsA and CVD, a 2013 systematic review by

28

Jamnitski et al, found four studies, all reporting an increase in the respective CVD morbidity examined (including IHD, congestive heart failure as well as cerebrovascular and peripheral vascular disease). However, these studies included a diverse range of study designs, including both primary and secondary care populations, and patients with both psoriasis and psoriatic arthritis [11]. Most recently, a large study from UK primary care found that major adverse cardiovascular events (MACE) were more common in PsA patients not prescribed a disease modifying antirheumatic drug (DMARD), but not in those using DMARDS, compared to controls [12]. Our understanding of the prevalence of different CVDrelated comorbidities in AS and PsA remains unclear, as does the extent to which psoriasis plays a role in CVD comorbidity experienced by PsA patients [13]. Therefore, the aim of this study was to compare the prevalence of CVD-related comorbidity in patients with AS, PsA and Ps to matched cohorts free of inflammatory disease in UK primary care. We thus hypothesised that the prevalence of CVD-related comorbidities would be greater in patients with AS, PsA and Ps compared to matched populations.

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THE NEW ENGLAND JOURNAL OF MEDICINE

Original Article

September 3, 2015

Clinical Features and Outcomes of Takotsubo (Stress)

Cardiomyopathy

Since its first description in Japan in 1990,1 takotsubo (stress) cardiomyopathy has gained worldwide recognition.

However, after nearly 25 years of extensive ef-forts toward a better understanding of this dis-order, current knowledge remains limited. The disease is characterized by transient systolic and diastolic left ventricular dysfunction with a variety of wallmotion abnormalities.2,3 It predominantly affects elderly women and is often pre-ceded by an emotional or physical trigger,4 but the condition has also been reported with no evident trigger. In the acute phase, the clinical presentation, electrocardiographic findings, and biomarker profiles are often similar to those of an acute coronary syndrome. Although the cause of takotsubo cardiomyopathy remains unknown, the role of the brain–heart axis in the pathogen-esis of the disease has been described.5,6

Takotsubo cardiomyopathy, which derives its name from the Japanese word takotsubo (“octopus pot”) to describe the characteristic balloon-ing of the left ventricular apex, is generally recognized as a benign disorder. However, patients are at risk for recurrence even years after the first event, and data on in-hospital and long-term outcomes are limited.7-10 The potential role of catecholamine excess in the pathogenesis of takotsubo cardiomyopathy has been long de-bated,11 and as such beta-blockers

30