It is reported that there are over 360,000 childhood cancer survivors in the US today. Studies have shown that 70% of childhood cancer survivors in the US will develop at least one chronic health condition in the future, including cardiovascular disease.
Associated with the risk of developing cardiovascular disease is metabolic syndrome: a group of different conditions that increase the risk of developing heart disease, stroke and diabetes. The prevalence of metabolic syndrome in childhood cancer survivors is reported to range from 7% to 60%
Metabolic syndrome consists of five different risk factors. For metabolic syndrome to be diagnosed, at least three of these five conditions have to be present:
- A large waistline (abdominal obesity)
- High blood pressure
- High blood sugar
- High triglyceride levels
- Low HDL cholesterol levels ("good" cholesterol).
The prevalence of metabolic syndrome is associated with poor nutritional habits, such as diets that are high in fat and sugar. Previous studies have shown that childhood cancer survivors report consuming high amounts of fat and less than the recommended amount of fruit and vegetable in their diets, habits that are not optimal for heart health.
Metabolic syndrome, often characterized by abdominal obesity, increases the risk of cardiovascular disease.
It was this association that prompted the new research that has been published in Cancer, the peer-reviewed journal of the American Cancer Society.
The research team from St. Jude Children's Research Hospital in Memphis, TN, set out to investigate whether the lifestyle factors of childhood cancer survivors had any effect on their risk of developing metabolic syndrome.
They examined 1,598 childhood cancer survivors who had been cancer-free for 10 years or more, and were participating in the St. Jude Lifetime Cohort Study, a long-term study that records the health consequences of cancer survivors following their treatment.
The participants were asked to take part in medical and laboratory tests and to complete food frequency questionnaires. The healthiness of their lifestyles were assessed using the recommendations of the World Cancer Research Fund (WCRF) and the American Institute for Cancer Research (AICR).
The authors of the study found that 31.8% of the participants had metabolic syndrome and that 27% were deemed to follow the healthy lifestyle guidelines by meeting at least four of the seven recommendations set out by the WCRF and AICR.
The study found that women that did not follow the guidelines were 2.4 times more likely to develop metabolic syndrome than those that did follow them. Similarly, men who did not follow the guidelines were 2.2 times more likely.
Survivors 'can influence future health outcomes'
Dr. Kirsten Ness, one of the authors, says that their study is unique "because of the large, well characterized population of survivors of various diagnoses that we studied, many years from their original cancer diagnosis."
The team acknowledges that the study does have some limitations. Dietary intake may not have been reported accurately, and not every eligible participant took part in the study.
As the sample of participants was from one particular area of the country, the results may not be representative of the whole population. Finally, the study cannot rule out the possibility that other diet or lifestyle guidelines could have a bigger impact on metabolic syndrome prevalence.
The main conclusion that the authors have taken from their findings is that childhood cancer survivors should be able to influence their future health outcomes by adhering to a healthy lifestyle. Dr. Ness says:
"Cancer survivors should not smoke. In addition, adopting a lifestyle that includes maintaining a healthy body weight, regular physical activity, and a diet that includes fruits and vegetables - and which limits refined sugars, excessive alcohol, red meat and salt - has potential to prevent development of the metabolic syndrome."
The authors also say that "additional work is needed to evaluate the impact of lifestyle interventions on risk for metabolic syndrome among childhood cancer survivors." Currently, the National Heart, Lung and Blood Institute recommend a healthy diet, maintaining a healthy weight and being physically active as the best ways to prevent metabolic syndrome.
Recently, a study published in Nature Communications suggested that cholesterol promotes the growth of cancer.
Written by James McIntosh