Affiliation: | 1.Department of Health and Exercise Science,University of Oklahoma,Norman,USA;2.Department of Medicine, Hematology Section,University of Oklahoma Health Sciences Center,Oklahoma City,USA;3.Department of Medicine, Cardiovascular Section,University of Oklahoma Health Sciences Center,Oklahoma City,USA;4.Children’s Medical Research Institute (CMRI) Metabolic Research Center,University of Oklahoma Health Sciences Center,Oklahoma City,USA;5.Department of Veteran Affairs Medical Center,Oklahoma City,USA |
Abstract: | ObjectiveTo determine whether differences in vascular reactivity existed among normal weight, overweight, and obese older men and women, and to examine the association between abdominal fat distribution and vascular reactivity.MethodsEighty-seven individuals who were 60 years of age or older (age = 69 ± 7 yrs; mean ± SD) were grouped into normal weight (BMI < 25; n = 30), overweight (BMI ≥ 25 and < 30; n = 28), or obese (BMI ≥ 30; n = 29) categories. Calf blood flow (BF) was assessed by venous occlusion strain-gauge plethysmography at rest and post-occlusive reactive hyperemia.ResultsPost-occlusive reactive hyperemia BF was lower (p = 0.038) in the obese group (5.55 ± 4.67 %/min) than in the normal weight group (8.34 ± 3.89 %/min). Additionally, change in BF from rest to post-occlusion in the obese group (1.93 ± 2.58 %/min) was lower (p = 0.001) than in the normal weight group (5.21 ± 3.59 %/min), as well as the percentage change (75 ± 98 % vs. 202 ± 190 %, p = 0.006, respectively). After adjusting for age, prevalence in hypertension and calf skinfold thickness, change in BF values remained lower (p < 0.05) in obese subjects compared to the normal weight subjects. Lastly, the absolute and percentage change in BF were significantly related to BMI (r = -0.44, p < 0.001, and r = -0.37, p < 0.001, respectively) and to waist circumference (r = -0.36, p = 0.001, and r = -0.32, p = 0.002).ConclusionObesity and abdominal adiposity impair vascular reactivity in older men and women, and these deleterious effects on vascular reactivity are independent of conventional risk factors. |