title: Weight loss alone improves conduit and resistance artery endothelial function in young and older overweight/obese adults.
abstract: Obesity is associated with vascular endothelial dysfunction, as indicated by impaired endothelium-dependent dilation. Presently there is no direct evidence that energy intake-restricted weight loss alone improves conduit or resistance artery endothelium-dependent dilation, the mechanisms involved, or whether improvements differ with patient age. A total of 40 overweight or obese (body mass index: >or=25<40 kg/m(2)) nondiabetic men and women aged 21 to 69 years completed 12 weeks of reduced energy intake (n=26; 15 male) or attention control (n=14; 9 male) and 4 weeks of weight maintenance (randomized trial). Energy intake restriction reduced estimated total energy intake (33%), body weight (10.5%), total and abdominal body fat, plasma leptin, oxidized low-density lipoprotein, and improved several metabolic risk factors. Brachial artery flow-mediated dilation was increased by 30% (6.0+/-0.7% versus 7.9+/-0.7%Delta; P=0.01; n=17). Peak forearm blood flow during intrabrachial artery infusion of acetylcholine was increased by 26% (16.8+/-1.4 versus 21.1+/-1.9 mL/100 mL per minute; P<0.05; n=15); this was inversely related to the reduction in the abdominal visceral:subcutaneous fat ratio (r=-0.46; P<0.05) and was abolished by inhibition of NO synthesis with N(G)-monomethyl-L-arginine. Improvements in endothelium-dependent dilation were not related to age: mean increases in subjects >50 years of age were similar to or greater than those <50 years of age. Energy intake-restricted weight loss alone is an effective intervention for improving peripheral conduit and resistance artery endothelial function in young and older overweight/obese adults. The improvements in resistance artery function are mediated by an increase in NO bioavailability and are related to reductions in abdominal visceral fat.
authors.affiliation: Department of Integrative Physiology, UCB 354, University of Colorado, Boulder, CO 80309, USA. gpierce@colorado.edu
authors.forename: Gary L
authors.initials: GL
authors.lastname: Pierce
authors.forename: Stacy D
authors.initials: SD
authors.lastname: Beske
authors.forename: Brooke R
authors.initials: BR
authors.lastname: Lawson
authors.forename: Kara L
authors.initials: KL
authors.lastname: Southall
authors.forename: Francoise J
authors.initials: FJ
authors.lastname: Benay
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Donato
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Seals
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001132:Arm / Q000098:blood supply; D001823:Body Composition; D001916:Brachial Artery / Q000503:physiopathology; D031204:Caloric Restriction; D004730:Endothelium, Vascular / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D009765:Obesity / Q000097:blood / Q000178:diet therapy* / Q000503:physiopathology; D050177:Overweight / Q000097:blood / Q000178:diet therapy* / Q000503:physiopathology; D012039:Regional Blood Flow; D014655:Vascular Resistance; D015431:Weight Loss