Chemotherapy Seems to Increase Risk of Metabolic Syndrome
A study strongly suggests that women who are treated with chemotherapy before or after breast cancer surgery have a higher risk of developing metabolic syndrome.
Metabolic syndrome is a collection of five symptoms:
- high blood pressure
- high fasting blood sugar
- large waistline
- high triglyceride levels
- low HDL cholesterol levels
that happen at the same time. A person has to have three of the above symptoms to be diagnosed with metabolic syndrome.
Having metabolic syndrome increases your risk of heart disease, stroke, and diabetes.
A study strongly suggests that women who are treated with 12 to 18 weeks of chemotherapy before or after surgery to remove early-stage breast cancer have a higher risk of developing metabolic syndrome.
The research was published in the Sept. 1, 2016 issue of the journal Cancer. Read “An observational study to examine changes in metabolic syndrome components in patients with breast cancer receiving neoadjuvant or adjuvant chemotherapy.”
Doctors call treatments given before surgery neoadjuvant treatments. Treatments given after surgery are called adjuvant treatments.
The study included 86 women diagnosed with stage I to stage III breast cancer who had not been diagnosed with metabolic syndrome:
- 46 women were premenopausal
- 40 women were postmenopausal
- 89% were diagnosed with stage I or stage II breast cancer
- 21% had chemotherapy before surgery
- 44% of the women were white, 30% were Hispanic, 8% were Black, and 7% were Asian
- 49% had never smoked
The women received several different chemotherapy regimens:
- 42% of the women were treated with Adriamycin (chemical name: doxorubicin) and Cytoxan (chemical name: cyclophosphamide) plus Taxol (chemical name: paclitaxel)
- 36% were treated with Taxotere (chemical name: docetaxel) and Cytoxan
- 9% were treated with carboplatin plus Taxol
- 7% were treated with Adriamycin and Cytoxan
- 6% were treated with Taxotere, Cytoxan, and Herceptin (chemical name: trastuzumab)
One week before the women started chemotherapy and one week after chemotherapy ended, the researchers assessed the women for the five metabolic syndrome symptoms and also measured other factors such as weight, body mass index (BMI), body fat percentage, and lean body mass.
After chemotherapy, 72.5% of the women were diagnosed with metabolic syndrome. Each of the five symptoms of metabolic syndrome was found to be worse after chemotherapy was completed. These differences were statistically significant, which means they were likely due to the chemotherapy and not just because of chance. There were no differences in metabolic syndrome symptom changes between premenopausal and postmenopausal women.
After chemotherapy, metabolic syndrome symptom changes were:
- average waistline measurement increased from 34.1 inches to 35.7 inches
- average systolic blood pressure increased from 122 to 128
- average diastolic blood pressure increased from 83 to 90
- average fasting blood sugar increased from 97.2 mg/dL to 117.0 mg/dL
- average triglycerides increased from 108.7 to 128.7
- average HDL cholesterol decreased from 57.9 to 50.6
Systolic blood pressure is the top number in a blood pressure reading and measures the pressure in your arteries when your heart contracts. Diastolic blood pressure is the bottom number in a blood pressure reading and measures the pressure in your arteries when the heart is resting.
Before chemotherapy treatment, most women in the study had only one metabolic syndrome symptom. After chemotherapy, most women in the study had four metabolic syndrome symptoms.
After chemotherapy, the women also had unhealthy changes in other body measurements:
- average weight increased from 152.5 pounds to 164.6 pounds
- average BMI increased from 25.9 to 29.0 (BMI of 25 to 29.9 is considered overweight)
- average body fat percentage increased from 33.1% to 36.0%
- average total cholesterol increased from 185.5 to 201.9
- average fasting insulin levels increased from 18.9 mlU/mL to 32.6 mlU/mL
- average blood C-reactive protein levels, a marker of inflammation, increased from 0.37 mg/L to 0.49 mg/L
“This is a very interesting paper,” said Marisa Weiss, M.D., founder and chief medical officer of Breastcancer.org. “It strongly suggests that chemotherapy -- and all of the medicines that go with it, including steroids -- increases the risk for metabolic syndrome and weight gain. Steroids may be given in high doses along with Taxol to minimize any reactions to that medicine and are known to increase appetite and alter metabolism.
“The best advice for women who will be treated with chemotherapy is to eat well and exercise regularly to minimize any weight gain and changes in metabolism that can happen during chemotherapy,” she continued. “But I know this isn’t easy when chemotherapy makes your sense of taste change and leaves you feeling exhausted and nauseated.”
You may want to talk to a registered dietitian about how to create a healthy eating plan tailored to your specific needs and likes that’s low in processed foods, sugar, and trans fats. If you can’t work with a registered dietitian, the U.S. Department of Agriculture’s 2015-20 Dietary Guidelines for Americans recommend eating a variety of nutrient-dense foods, including:
- a variety of vegetables: dark green, red and orange, beans and peas, starchy, and others
- fruit, especially whole fruits
- grains, at least half of which are whole grains
- fat-free or low-fat dairy
- a variety of protein foods, including seafood, lean meats and poultry, eggs, beans and peas, nuts, seeds, and soy products
In the past, women who were being treated with chemotherapy were advised to take it slow. But research has shown that it’s better for women receiving chemotherapy to be as active as possible -- even low intensity exercise such as gentle stretching and walking is better than being inactive.
If you’re being treated with chemotherapy for breast cancer, try to make exercise and healthy eating part of your daily routine. Think of eating well and exercise as two more important parts of your overall treatment plan that helps you recover and stay healthy.
Talk to your doctor about how much and how often you should exercise. Ask around and see if any breast cancer support groups near you have organized exercise classes. If you can’t find an exercise class through a breast cancer group, consider joining another exercise class or walking with a friend. There’s a good chance that exercising with other people will give you the motivation and support to make regular exercise part of your recovery. Find the right exercise routine for YOU and then do your best to stick with it.
Editor’s Note: This article was updated on March 23, 2019, with clarifications about the study participants’ chemotherapy regimens.
— Last updated on February 22, 2022, 10:01 PM
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