Impact of Body Mass Index on the Association of Ankle-Brachial Index With All-Cause and Cardiovascular Mortality: Results from the National Health and Nutrition Examination Survey

Mohammad-Ali Jazayeri; Salman Waheed; Zubair Shah; Deepak Parashara; Kamal Gupta

doi:10.1016/j.mayocpiqo.2019.08.006

Impact of Body Mass Index on the Association of Ankle-Brachial Index With All-Cause and Cardiovascular Mortality: Results from the National Health and Nutrition Examination Survey

Mayo Clin Proc Innov Qual Outcomes. 2019 Oct 22;3(4):409-417. doi: 10.1016/j.mayocpiqo.2019.08.006. eCollection 2019 Dec.

Authors

Mohammad-Ali Jazayeri¹, Salman Waheed², Zubair Shah¹, Deepak Parashara³, Kamal Gupta¹

Affiliations

¹ Department of Cardiovascular Medicine, University of Kansas Medical Center, Kansas City, KS.
² Division of Cardiovascular Disease, University of Alabama Birmingham, AL.
³ Division of Cardiovascular Disease, Kansas City Veterans Affairs Medical Center, MO.

Abstract

Objective: To assess the influence of body-mass index (BMI) on the association of ankle-brachial index (ABI) with mortality.

Patients and methods: We conducted a prospective study of National Health and Nutrition Examination Survey participants enrolled from January 1, 1999 to December 31, 2002 with BMI and ABI data available. ABI categories were <0.9 (low), 0.9 to 1.3 (reference), and >1.3 (high). BMI categories were <30 kg/m² (nonobese) and ≥30 kg/m² (obese). Cardiovascular (CV) and all-cause mortality were assessed by National Death Index records. Cox proportional-hazards models and Kaplan-Meier survival estimates were used to compare groups.

Results: In total, 4614 subjects were included, with mean age 56±12 years and BMI 28±6 kg/m². Median follow-up was 10.3 years (interquartile range [IQR]: 9.3 to 11.4 years). Low and high ABI were present in 7% and 8%, respectively. After adjustment, low ABI was associated with increased all-cause and CV mortality in nonobese (hazard ratio [HR] 1.5, 95% CI, 1.1-2.1 for all-cause and 3.0 [1.8-5.1] for CV mortality) and obese individuals (1.8 [1.2-2.7] and 2.5 [1.2-5.6], respectively) compared with reference. High ABI was associated with increased CV mortality in nonobese (2.2 [1.1-4.5]) but not obese patients; it was not associated with all-cause mortality overall or when stratified by BMI.

Conclusion: In a US cohort, weight influenced the prognostic significance of high ABI. This may be related to technical factors reducing compressibility of the calf arteries in obese persons compared with those who are nonobese.

Keywords: ABI, ankle-brachial index; BMI, body mass index; BP, blood pressure; CV, cardiovascular; LE, lower extremity; MAC, medial arterial calcification; NHANES, National Health and Nutrition Examination Survey.