Low-Fat Diet Designed for Weight Loss But Not Weight Maintenance Improves Nitric Oxide-Dependent Arteriolar Vasodilation in Obese Adults

• Published in: Nutrients 2019-06, Vol.11 (6), p.1339
• Main Authors: Mahmoud, Abeer M, Hwang, Chueh-Lung, Szczurek, Mary R, Bian, Jing-Tan, Ranieri, Christine, Gutterman, David D, Phillips, Shane A
• Format: Article
• Language: English
• Subjects: acetylcholine; Adolescent; Adult; Adults; Anthropometry; Apolipoproteins; Bioavailability; Body fat; Body mass; Body mass index; Body size; Body weight; Body weight loss; Body Weight Maintenance - physiology; Carbohydrates; cardiovascular; Cholesterol; Diabetes; Diet; Diet, Fat-Restricted; Dual energy X-ray absorptiometry; Female; flow-induced dilation; Gastrointestinal surgery; Humans; Hypertension; hypocaloric; Insulin; Intervention; isocaloric; Lipids; Lipoproteins; Low fat diet; Maintenance; Male; Metabolic syndrome; Microvasculature; Microvessels - metabolism; Microvessels - physiology; Middle Aged; Nitric oxide; Nitric Oxide - analysis; Nitric Oxide - metabolism; Nutrient deficiency; Nutrition research; Obesity; Obesity - diet therapy; Obesity - physiopathology; Proteins; Sensitivity; Subcutaneous Fat - blood supply; Vasodilation; Vasodilation - physiology; Weight control; Weight loss; Weight Loss - physiology; Weight reduction; Young Adult
• ISSN: 2072-6643; 2072-6643
• DOI: 10.3390/nu11061339

Obesity is associated with microvascular dysfunction. While low-fat diet improves cardiovascular risk, its contributions on microvascular function, independent of weight loss, is unknown. We tested the hypothesis that nitric oxide (NO)-dependent vasodilation in microvessels is improved by low-fat diets designed for weight loss (LFWL) compared to low-fat weight maintenance (LFWM) diet. Obese adults were randomly assigned to either a LFWL diet ( 11) or LFWM diet ( 10) for six weeks. Microvessels were obtained from gluteal subcutaneous fat biopsies before and after the intervention for vascular reactivity measurements to acetylcholine (Ach) and flow, with and without L-NAME or indomethacin. Vascular and serum NO and C-reactive protein (CRP) were also measured. LFWL diet increased flow-induced (FID) and ACh-induced dilation (AChID); an effect that was inhibited by L-NAME. Conversely, LFWM diet did not affect FID or AChID. Indomethacin improved FID and AChID in the baseline and this effect was minimized in response to both diets. Serum NO or CRP did not change in response to either diet. In conclusion, LFWL diet improves microvascular reactivity compared to LFWM diet and increased vascular NO contribution to the improved microvascular dilation. These data suggest that weight reduction on low fat diet is critical for microvascular health.