Page 22 - Today's Dietitian (February 2020)

the most common cancers in children and adolescents. Risk of lifestyle, including the role of diet and exercise, should be dis-
heart failure is greatest in people with two or more CVD risk cussed with all patients with cancer before and after comple-
factors, and blood pressure management is an important strat- tion of their cancer therapy.” 1
egy in its prevention. 1
Ischemia already may be present in many adults, and Mutual Risk Factors
it can be enhanced by some cancer treatments, including Both cancer risk and CVD risk are associated with various
7
a variety of chemotherapy agents and radiation therapy. risk factors, some that can’t be modified (such as family his-
This may occur through changes in lipid metabolism and tory of the disease) and some that can (through lifestyle
inflammation-mediated acceleration of atherosclerosis. choices and/or medical care). One reason for the frequent
Hypertension, smoking, dyslipidemia, and insulin resistance overlap of cancer and CVD is that age is a steady independent
all seem to trigger atherosclerosis by promoting endothelial risk factor for both. Although a few cancers (such as neuro-
cells’ expression of adhesion molecules and enabling blastoma, nephroblastoma, and certain sarcomas) strike pre-
leukocyte attachment to blood vessel walls. 8 dominantly in childhood, 78% of the new cancer diagnoses in
People at greatest risk of adverse cardiovascular side developed countries occurs in those aged 55 and older. How-
effects of cancer treatment are those with older age, a history ever, it’s important to remember that associations between
of myocardial infarction or other heart disease, or two or age and onset of both cancer and CVD can be highly influ-
more major risk factors (eg, smoking, hypertension, diabetes, enced by modifiable risk factors, including diet, physical
1
dyslipidemia, obesity). Survivors of childhood cancer also are activity, BMI, and smoking. 8
at increased risk of cardiovascular late effects. Current clinical
practice guidelines state that clinicians should screen for and Tobacco Smoking
actively manage the aforementioned major modifiable CVD Tobacco smoking contributes to all stages of atherosclerosis by
risk factors in all patients receiving or previously treated with decreasing levels of nitric oxide and causing vasomotor dys-
potentially cardiotoxic treatments. These guidelines also say function, while the multiple carcinogens it contains signifi-
that a heart-healthy lifestyle, including the role of a healthful cantly increase cancer risk. Tobacco promotes both CVD and
diet and exercise, should be discussed as part of their long- cancer by causing oxidative stress that leads to endothelial
term follow-up care. 1,9 and DNA damage and by increasing inflammation. 8
Dietitians, therefore, can be valuable members of the car-
dio-oncology health care team with skills to address side Diabetes
effects of cancer treatment that affect the ability to eat and Both type 1 and type 2 diabetes increase risk of CVD and
nourish the body, promote dietary choices that affect CVD risk cancer. Risk from type 2 diabetes involves inflammation,
factors, and help set priorities among those choices on an indi- hyperglycemia, hyperinsulinemia, and elevated levels of insu-
8
vidual basis. The American Society of Clinical Oncology clini- linlike growth factor (IGF). Elevated triglyceride-rich lipo-
cal practice guidelines state that patients need to be advised proteins commonly seen in type 2 diabetes increase risk of
that cardiac dysfunction can be a progressive disorder that myocardial infarction and stroke through inflammation and
10
initially may be asymptomatic. Therefore, “a heart-healthy enhanced formation of foam cells that lead to atherosclerosis.
Chronic hyperinsulinemia and resulting elevated IGF enhance
cancer development by promoting cell proliferation and inhib-
iting apoptosis (self-destruction of abnormal cells). 11-13 Elevated
insulin levels also decrease liver production of sex hormone–
CARDIO-ONCOLOGY binding globulin, thus increasing bioavailable estrogen and
testosterone, increasing risk of hormone-sensitive cancers.
12
GUIDELINES In type 1 diabetes, oxidative stress stemming from chronic
elevated blood glucose is considered the primary link to CVD,
possibly amplified by a dysfunctional immune response. 14,15
American Heart Association Type 1 diabetes has been associated with increased risk of 11
Scientific Statement on Cardio-Oncology Rehabilitation some cancers, but the link is less well understood at this time.
(CORE): www.ahajournals.org/doi/10.1161/CIR.000000 Some chemotherapeutic agents can worsen blood glucose
0000000679 control, and radiation therapy can increase risk of develop-
ing diabetes. Thus, dietitians’ skills in helping people modify
American Society of Clinical Oncology eating habits for better blood sugar levels can be valuable.
Clinical Practice Guideline on Prevention and Monitoring
of Cardiac Dysfunction in Survivors of Adult Cancers: Hyperlipidemia
https://ascopubs.org/doi/10.1200/JCO.2016.70.5400 Hyperlipidemia is a well-established risk factor for CVD. LDL
cholesterol traditionally has been the primary target for risk
National Comprehensive Cancer Network reduction, but very LDL, intermediate-density lipoprotein, and
10,16
Clinical Practice Guidelines to assess and address other non-HDL cholesterol fractions also are atherogenic.
survivorship (free after registration): www.nccn.org/ Evidence is inconclusive about any association of serum cho-
professionals/physician_gls/default.aspx lesterol and cancer risk. Current evidence suggests that the
inverse association between levels of LDL and cancer incidence
seen in some studies may be a result of the malignancy.
8
22 TODAY’S DIETITIAN • FEBRUARY 2020