Systolic inter-arm blood pressure difference and subclinical atherosclerosis: a population-based cohort study of 29 921 individuals.

Inter-arm blood pressure differences (IABPDs) can be caused by atherosclerosis. We investigated 29 921 men and women aged 50-64 years from the nationwide population-based Swedish CArdio Pulmonary bioImage Study (SCAPIS) to evaluate if IABPD is related to risk factors for atherosclerosis and can be used as a marker of atherosclerosis as evaluated by coronary artery calcium score, arterial segment involvement score on computed tomography, carotid ultrasound, and ankle-brachial index (ABI). The overall prevalence of systolic IABPD at least 10 mmHg was 2110/29 921 (7.1%). Individuals with IABPD at least 10 mmHg were significantly ( P  < 0.001) older, more often women, had higher BMI, nonhigh-density lipoprotein cholesterol, triglycerides, SBP and DBPs, and were more likely to have diabetes. In unadjusted analyses, IABPD at least 10 mmHg was associated with presence of coronary atherosclerosis, with more carotid arteries with plaque, and with pathological ABI. These associations were largely attenuated after adjustment for cardiovascular risk factors (age, sex, nonhigh-density lipoprotein cholesterol, systolic BP, smoking, diabetes, and the use of BP lowering drugs). Only ABI retained significance after these adjustments. In conclusion, a systolic IABPD of at least 10 mmHg in middle aged men and women is common in the general population, and can be used as a screening tool for subclinical atherosclerotic changes in coronary, carotid, and lower extremity arteries. However, these relationships were largely explained by correlations between IABPD and traditional cardiovascular risk factors.