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Link between PAD, radiation dose unclear in atomic bomb survivors
Among Japanese atomic bomb survivors, a relationship between radiation exposure and prevalence of peripheral artery disease was not evident, according to findings published in the Journal of the American Heart Association.
Researchers assessed past reports suggesting the association between total body irradiation at 0.5 Gy to 1 Gy and atherosclerosis, and whether the consequences of low to moderate doses of radiation included an increased risk for PAD.
“Our aim was to examine the association between radiation dose and PAD prevalence among atomic bomb survivors in the Adult Health Study from the Radiation Effects Research Foundation between 2010 and 2014,” Ikuno Takahashi, MD, PhD, of the department of clinical studies at the Radiation Effects Research Foundation in Hiroshima, Japan, and colleagues wrote. “This is the first clinical survey of survivors, made with noninvasive ankle-brachial blood pressure index, allowing us to properly investigate radiation-related PAD prevalence.”
The cross-sectional study consisted of 3,476 participants (mean age, 7 years; 41% men). Potential covariables included smoking history, systolic and diastolic BP, C-reactive protein, white blood cell count, BMI and indicators of three existing clinical conditions: hypertension, diabetes and dyslipidemia. Researchers surveyed individuals with any of the three clinical conditions regarding the use of medication for treatment of the disorders.
Researchers obtained the measurements and upstroke time by an automated oscillometer, with prevalent PAD being declared when a participant met an ankle-branchial index of 1 or less, including borderline (range, 0.91-0.99). Researchers identified 79 individuals with prevalent PAD based on having surgery (n = 10) or with an ABI of 1 or less (n = 69) at the time of the study.
The association between radiation exposure and PAD or upstroke time was assessed through multivariable regression analyses with the potential for cofounding factors, with the analysis indicating radiation dose is unrelated to PAD prevalence (OR = 0.83; 95% CI, 0.57-1.2). Upstroke time appeared to increase with radiation dose, but not significantly (1.09 ms/Gy; 95% CI, –0.17 to 2.36).
Further investigation is needed to determine whether prolonged upstroke time reflects radiation-induced vascular damage, researchers wrote.
“The advanced method for measuring [upstroke time] has been available only for a decade, and factors that might affect [upstroke time] are not yet fully clear,” Takahashi and colleagues wrote. – by Earl Holland
Disclosures: The authors report no relevant financial disclosures.