Increased Cardiovascular Risk Despite Healthier Lifestyle Characteristics in Hematopoietic Cell Transplant Survivors
In a study reported in the Journal of Clinical Oncology, Chow et al compared cardiovascular risk and risk factors in hematopoietic cell transplantation recipients with those in a matched general population sample. Hematopoietic cell transplantation survivors were at greater risk for cardiomyopathy, stroke, dyslipidemia, and diabetes, but at reduced risk for ischemic heart disease. Risk among transplant survivors was associated with modifiable lifestyle risk factors.
Study Details
The study involved 2,362 hematopoietic cell transplantation survivors of ≥ 1 year treated from 1970 to 2010 at Fred Hutchinson Cancer Research Center and a general population sample of 1,192 subjects from the National Health and Nutrition Examination Survey (NHANES) matched for sex, 10-year age interval, and race/ethnicity. Subjects were surveyed in 2010 and 2011 on current cardiovascular health and related lifestyle factors (smoking, diet, recreational physical activity).
A history of cancer was reported by 13% of the general population sample. Hematopoietic cell transplant survivors had a median age of 56 years and a median of 10.8 years since transplantation; 71.3% had received allogeneic hematopoietic cell transplantation.
Cardiovascular Risks
Compared with the general population, hematopoietic cell transplantation survivors had significantly higher rates of cardiomyopathy (4.0% vs 2.6%, P = .03), stroke (4.8% vs 3.3%, P = .04), dyslipidemia (33.9% vs 22.3%, P < .001), and diabetes (14.3% vs 11.7%, P = .04) and were less likely to have ischemic heart disease (6.1% vs 8.9%, P = .002). Rates of hypertension were similar in the two groups (27.9% vs 30.0%).
Transplant survivors were more likely to have normal body weight (43% vs 30%, 19% vs 34% obese; P < .001 for trend), had lower rates of smoking (never in 60% vs 49%, former in 32% vs 29%; P < .001 for trend), had greater fruit/vegetable intake (≥ 5 servings per day in 27% vs 7%, P < .001), and more frequently met recommended physical activity levels (65% vs 34%, P < .001), but more frequently were not working or had sedentary work activities (75% vs 58%; P < .001 for trend).
On multivariate analysis adjusting for sex, nonwhite race/ethnicity, current age, and body mass index, the greater risk for stroke, dyslipidemia, and diabetes and reduced risk for ischemic heart disease remained significant for the hematopoietic cell transplantation group. On multivariate analysis correcting for these factors plus current smoking, daily fruit vegetable intake, and recreational physical activity time, risks for cardiomyopathy, stroke, hypertension, dyslipidemia, and diabetes were significantly elevated in the hematopoietic cell transplantation group and risk for ischemic heart disease was nonsignificantly reduced.
Risk Factors in Hematopoietic Cell Transplantation Group
In analyses restricted to hematopoietic cell transplantation survivors, hypertension, dyslipidemia, and diabetes were independent risk factors for ischemic heart disease and cardiomyopathy (odds ratios [ORs] = 1.6–3.8) and smoking was an independent risk factor for ischemic heart disease and diabetes (ORs = 1.8–2.2). Obesity was a risk factor for hypertension, dyslipidemia, and diabetes (ORs = 2.0–2.5). Lower fruit/vegetable intake was associated with greater risk of dyslipidemia and diabetes (ORs = 1.4–1.8), and lower physical activity level was associated with greater risk of hypertension and diabetes (ORs = 1.4–1.5).
An analysis of potential risk reduction for ischemic heart disease, cardiomyopathy, and stroke showed that controlling dyslipidemia was associated with the greatest reduction (attributable risk = 46%–77%), with control of hypertension, diabetes, and smoking generally being associated with an attributable risk of approximately 30%. Control of obesity was associated with an attributable risk of 34% to 38% for hypertension, dyslipidemia, and diabetes, with control of smoking, diet, and physical activity being associated with an attributable risk of at least 25% for these conditions.
The investigators noted that despite having healthier lifestyles than those of the general population, survivors of hematopoietic stem cell transplantation experience a “greater burden of most cardiovascular conditions,” potentially as a result of pretransplantation or transplantation therapies. However, transplant survivors have a lower prevalence of ischemic heart disease; this may be due to pre-existing ischemic heart disease’s being a relative or absolute contraindication for hematopoietic cell transplantation, they said.
They concluded, “Attention of clinicians to conventional cardiovascular risk factors and modifiable lifestyle characteristics offers hope of reducing serious cardiovascular morbidity after hematopoietic cell transplantation.”
Eric J. Chow, MD, MPH, of Fred Hutchinson Cancer Research Center, is the corresponding author for the Journal of Clinical Oncology article.
The study was supported by National Institutes of Health grants and a Leukemia and Lymphoma Society Special Fellowship in Clinical Research. The study authors reported no potential conflicts of interest.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
