Cardiometabolic disease, defined as cardiovascular disease (CVD) or type 2 diabetes (T2D), is the primary comorbidity in patients with cancer. But new research is linking healthy lifestyle with both the prevention of new cancer and the reduced risk for cardiometabolic disease among those with previous cancer. 

The study, conducted by Zhi Cao, MSc, from the School of Public Health, Tianjin Medical University, Tianjin, China, and colleagues, showed that healthy living significantly mitigated the risk for incident cancer, cardiovascular disease, and type 2 diabetes in a healthy population, and lowered the risk for CVD and TD2 in those who developed cancer or had a history of cancer.

“These findings highlight the benefits of adopting a combination of healthy behavioral practices in reducing the risk for CVD and T2D complications among patients with and without prevalent cancer,” the researchers conclude.

Results of the population-based, observational study were published in JACC: CardioOncology.

“I think this study was unique in that it examined the bidirectional interplay between cancer and CVD,” said Erin D. Michos, MD, associate professor of medicine and epidemiology and associate director of preventive cardiology at the Ciccarone Center for the Prevention of Heart Disease at the Johns Hopkins University School of Medicine in Baltimore, Maryland, who coauthored an editorial accompanying the paper.

While prior studies have examined the risk of incident cancer and incident CVD associated with lifestyle factors, Michos said the investigators went one step further to examine the risk of CVD among individuals following a cancer diagnosis or those with a prior history of cancer. “Even after a cancer diagnosis, following a healthy lifestyle has continued benefits,” she said.

The researchers examined the impact of healthy living on 432,000 people between the ages of 40 and 70 who were enrolled in the UK Biobank between April 2006 and December 2010.  The study consisted of two cohorts, including those with new cancers and those with previous diagnoses.

The healthy lifestyle index (HLI) was defined by five factors: not smoking, meeting the recommended guidelines for physical activity, following a healthy diet, moderate alcohol consumption, and moderate sleep duration.

In those without prior cancer, the researchers found that each one-point increment in HLI was associated with an 8{44affb6c5789133b77de981cb308c1480316fee51f5fd5f1575b130f48379a33} reduction in new incident cancer (hazard ratio [HR] 0.92; 95{44affb6c5789133b77de981cb308c1480316fee51f5fd5f1575b130f48379a33} CI, 0.91-0.93). Over 15 years, 6.38{44affb6c5789133b77de981cb308c1480316fee51f5fd5f1575b130f48379a33} and 4.18{44affb6c5789133b77de981cb308c1480316fee51f5fd5f1575b130f48379a33} of these patients with cancer developed CVD or T2D, respectively. Healthy lifestyle mitigated the risk of transition from cancer to CVD or T2D with HRs per one-point increment in the HLI of 0.90 (95{44affb6c5789133b77de981cb308c1480316fee51f5fd5f1575b130f48379a33} CI, 0.86-0.94) and 0.84 (95{44affb6c5789133b77de981cb308c1480316fee51f5fd5f1575b130f48379a33} CI, 0.79-0.89), respectively.

In cancer survivors, each one-point increment in HLI was associated with a 10{44affb6c5789133b77de981cb308c1480316fee51f5fd5f1575b130f48379a33} lower risk for CVD (HR 0.90; 95{44affb6c5789133b77de981cb308c1480316fee51f5fd5f1575b130f48379a33} CI, 0.87-0.93) and a 13{44affb6c5789133b77de981cb308c1480316fee51f5fd5f1575b130f48379a33} reduction in T2D (HR 0.87; 95{44affb6c5789133b77de981cb308c1480316fee51f5fd5f1575b130f48379a33} CI, 0.83-0.91).  

“The authors looked at a very large and well-established cohort with the UK Biobank, which is a really phenomenal resource,” said Stephen Juraschek, MD, PhD, assistant professor, Harvard Medical School and research director at the Hypertension Center at the Beth Israel Deaconess Medical Center in Boston, Massachusetts. “But [the results] are largely confirmatory with what we know about these healthy lifestyle recommendations.”

Michos says one limitation was that the health associations indicated could not be directly attributed to the factors in the HLI score. For example, those following a healthy lifestyle might have been prone to doing other health-seeking behaviors already, such as visiting a healthcare provider for preventive screening, complying with routine health maintenance, and taking preventive medications.

She says another weakness was the connection to alcohol intake as a healthy lifestyle factor. “Alcohol is a risk factor for many cancers, even moderate alcohol use…[and] alcohol is a risk factor for atrial fibrillation,” she said. “Its use is not endorsed as a preventive strategy by the American Heart Association or the American Society of Clinical Oncology.

The study results also linked a healthy lifestyle with an increased risk for prostate cancer and melanoma, which the authors felt was due to the likelihood of more prostate cancer screenings leading to diagnosis and more UV exposure from outdoor activities.

Given that lifestyle factors were only obtained at baseline, not accounting for changes over time, the study authors note that future research should “examine the effect of the lifestyle trajectory on CVD and T2D in patients with cancer.”

With all the existing evidence around the benefits of a healthy lifestyle, Jurascheck says further research should center on how to roll out healthier interventions to the general population.

“How do we improve policies to promote healthier eating and healthier food choices in the supply chain, or to ensure people are less sedentary?” he said. “What can we do culturally to promote those kinds of behaviors?”

More work is also needed to identify therapies that will improve both cardiovascular health and cancer outcomes, perhaps by targeting inflammation, which is a shared mechanistic explanation for the overlap of the two diseases, notes Michos. “There is a critical role of a healthy lifestyle for prevention of both diseases,” she said.

The trial was supported by the National Natural Science Foundation of China. The authors disclose no conflict of interest relevant to the contents of this paper.

JACC: CardioOncology, Vol 3 No. 5, 2021; December 2021, Abstract. Editorial.

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