Effects of diet and exercise training on neurovascular control during mental stress in obese women

• Published in: Brazilian journal of medical and biological research Vol. 39; no. 1; pp. 53 - 62
• Main Authors: Tonacio, A C, Trombetta, I C, Rondon, M U P B, Batalha, L T, Kuniyoshi, F H S, Laterza, M C, Suzuki, P H, Gowdak, M M G, Barretto, A C P, Halpern, A, Villares, S M F, Negrão, C E
• Format: Journal Article
• Language: English
• Published: Brazil Associação Brasileira de Divulgação Científica 01.01.2006
• Subjects: Adult; BIOLOGY; Body Mass Index; Diet, Reducing; Exercise; Female; Forearm - blood supply; Humans; MEDICINE, RESEARCH & EXPERIMENTAL; Muscle, Skeletal - blood supply; Muscle, Skeletal - innervation; Obesity - physiopathology; Obesity - psychology; Obesity - therapy; Plethysmography; Stress, Psychological - physiopathology; Sympathetic nervous system; Sympathetic Nervous System - physiopathology; Time Factors; Vasodilation; Weight loss; Sympathetic nervous system; Vasodilation; Weight loss
• ISSN: 0100-879X; 1414-431X; 0100-879X; 1414-431X
• DOI: 10.1590/s0100-879x2006000100006

Since neurovascular control is altered in obese subjects, we hypothesized that weight loss by diet (D) or diet plus exercise training (D + ET) would improve neurovascular control during mental stress in obese women. In a study with a dietary reduction of 600 kcal/day with or without exercise training for 4 months, 53 obese women were subdivided in D (N = 22, 33 +/- 1 years, BMI 34 +/- 1 kg/m2), D + ET (N = 22, 33 +/- 1 years, BMI 33 +/- 1 kg/m2), and nonadherent (NA, N = 9, 35 +/- 2 years, BMI 33 +/- 1 kg/m2) groups. Muscle sympathetic nerve activity (MSNA) was measured by microneurography and forearm blood flow by venous occlusion plethysmography. Mental stress was elicited by a 3-min Stroop color word test. Weight loss was similar between D and D + ET groups (87 +/- 2 vs 79 +/- 2 and 85 +/- 2 vs 76 +/- 2 kg, respectively, P < 0.05) with a significant reduction in MSNA during mental stress (58 +/- 2 vs 50 +/- 2, P = 0.0001, and 59 +/- 3 vs 50 +/- 2 bursts/100 beats, P = 0.0001, respectively), although the magnitude of the response was unchanged. Forearm vascular conductance during mental stress was significantly increased only in D + ET (2.74 +/- 0.22 vs 3.52 +/- 0.19 units, P = 0.02). Weight loss reduces MSNA during mental stress in obese women. The increase in forearm vascular conductance after weight loss provides convincing evidence for D + ET interventions as a nonpharmacologic therapy of human obesity.