Page 888 - Cardiac Nursing

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864 PA R T V / Health Promotion and Disease Prevention

Table 38-2 ■ CARDIOVASCULAR-RELATED CONDITIONS ASSOCIATED WITH OVERWEIGHT AND OBESITY
Condition Details About Disease or Condition
CHD Nurses’ Health Study data reveal a 3.3-fold increase in risk for developing CHD with a BMI of 29 compared to
women with a BMI of 21; a BMI between 27 and 29 has a relative risk of 1.8. Generally, risk increases as BMI
increases.
Hypertension BP is often increased in overweight persons. In the SOS, 44% to 51% were hypertensive at baseline. High BP in normal
weight persons produces concentric hypertrophy of the heart with ventricular wall thickening; eccentric dilatation oc-
curs in overweight individuals. The combination of hypertension and overweight leads to ventricular wall thickening
and increased heart volume, and consequently to increased likelihood of heart failure.
Dyslipidemia (low HDL, high Weight gain is associated with increased LDL-cholesterol and reduced HDL; there is a positive correlation between
LDL, elevated triglycerides) triglyceride level and BMI.
Elevated plasma glucose, insulin The risk of type 2 diabetes increases with the duration of overweight and the degree of overweight, for example, in the
resistance, and metabolic Nurses’ Health Study, women with a BMI of 35 had a 40-fold increase in relative risk. Risk for diabetes also
syndrome increases with the amount of central adiposity.
Weight gain increases diabetes risk; more than 60% of diabetes cases can be attributed to overweight.
Obesity leads to increased insulin secretion and insulin resistance, which is considered the trademark of the metabolic
syndrome. A central trait of the metabolic syndrome is increased central adiposity or visceral fat, which releases free
fatty acids that impair insulin clearance by the liver and modified peripheral metabolism.
Increased waist circumference Given similar levels of LDL cholesterol, CHD risk is significantly higher in persons with small dense LDL, which is
associated with central body fat. A positive association has been shown between central adiposity and elevated triglyc-
erides and decreased HDL.
Inflammation Obesity is associated with an increase in circulating inflammatory markers, for example, cytokines (interleukin-6,
interleukin-18, and P-selectin), as well as C-reactive protein (CRP). Excess cytokines, which are secreted by the
adipose cells and called adipokines, are associated with insulin resistance and considered a predictor of atherosclerotic
events. Levels of adiponectin and interleukin-10, anti-inflammatory cytokines, are reduced in the presence of weight
gain and obesity. A reduction in CRP has been shown to be directly related to the amount of weight lost, fat mass, and
change in waist circumference.
Congestive heart failure Obese patients experience an increase in stroke volume and cardiac output resulting in hypertrophy of the left ventricle.
This can occur with or without hypertension. These changes in the ventricle predispose an individual to left-sided
heart failure and often dilated cardiomyopathy. An increase in BMI is also related to changes in the right side of the
heart, most frequently due to an increase in pulmonary hypertension from sleep apnea.
Stroke To adequately perfuse the higher volume of adipose tissue, obese persons have an increased total blood volume. Stroke
and atrial fibrillation are more common in the obese patient due to dilatation of the atria from a higher fluid volume.
Thromboembolic events A waist circumference 39 in. (100 cm) in men is related to an increase risk of venous thromboembolism. Women
appear to have an increased risk of pulmonary embolism associated with an increased BMI, but this relationship is un-
clear in men.
Cardiac arrhythmias/ECG The dilated cardiomyopathy that can be seen in obesity increases one’s risk for sudden cardiac death. Obesity could also
changes cause changes in the electrocardiogram. The heart can be somewhat displaced because of an elevated diaphragm while
lying down. There is also a greater distance between the electrodes and the heart due to an increase in adipose tissue.
One may see some ST-segment or T-wave abnormalities and left atrial abnormalities due to cardiac dilatation. A
prolonged QT interval may also be seen, which predisposes one to cardiac arrhythmias.

weight gain should be addressed through lifestyle approaches, with sessment (Fig. 38-2). This algorithm is focused on weight-related
the emphasis on smoking abstinence. 15 When attempting to ad- assessment and treatment and does not include evaluation for
dress multiple behavior changes, rather than concurrent treatment, other disorders for which the patient may be seeing a health care
an improved outcome may result from a sequential approach that provider. As noted in Figure 38-2, if the patient’s BMI and waist
focuses on assisting the patient to stop smoking before initiating circumference are in the normal range, these parameters should
behavioral weight-management strategies. 36 be measured again in 2 years. For the patient who is of normal
weight, brief counseling about prevention of future weight gain
should be provided. Knowing that weight gain can be expected
CLINICAL EVALUATION from most patients, maintenance of weight is a positive outcome
and patients should receive reinforcement for maintaining a
Baseline assessment of the cardiac patient includes the BMI, healthy weight.
waist circumference, and cardiovascular risk profile, as well as
noncardiovascular conditions, for example, sleep apnea, OA, gall- Clinical History
stones, and gynecologic abnormalities. These factors need to be
evaluated so that obesity is treated in the context of the patient’s For the patient whose parameters are not normal, assessment
7
risk profile and existence of comorbid conditions. Weight loss needs to include the patient’s history, including prior excess
frequently ameliorates risks by reducing blood pressure and weight or weight fluctuations. If not done previously, a physical
triglycerides, as well as lessens the impact of other comorbid con- examination and laboratory measurements to assess lipid profile,
ditions. Therefore, risk factors should be addressed through glucose level, and related parameters need to be performed. The
weight loss treatment. The NHLBI Evidence report 15 includes an provider needs to identify existing cardiovascular disease and the
algorithm that addresses the treatment decisions based on that as- presence of possible end-organ damage.