Endothelial nitric oxide synthase Glu298Asp gene polymorphism influences body composition and biochemical parameters but not the nitric oxide response to eccentric resistance exercise in elderly obese women Tatiane Gomes Teixeira 1 , Ramires Alsamir Tibana 1 , Dahan da Cunha Nascimento 1 , Nuno Manuel Frade de Sousa 2 , Vinicius Carolino de Souza 1,4 , Denis C esar Leite Vieira 3 , Ot avio de Toledo N obrega 4 , Jeeser Alves de Almeida 5 , James Navalta 6 and Jonato Prestes 1 1 Catholic University of Brasilia, Graduation Program on Physical Education, Brasilia, 2 Laboratory of Exercise Physiology, Faculty Estacio of Vitoria, Vitoria, ES, 3 Universitary Center of Brasilia (UDF), 4 University of Brasilia, Brasilia, Brazil, 5 Department of Physical Education of Federal University of Mato Grosso do Sul, Brazil and 6 Department of Kinesiology and Nutrition Sciences, University of Nevada, Las Vegas, NV, USA Summary Correspondence Jonato Prestes, Graduation Program on Physical Education, Catholic University of Brasilia - Q.S. 07, Lote 01, EPTC – Bloco G, 71966-700 – Taguatinga – Federal District, Brasilia, Brazil E-mail: jonatop@gmail.com Accepted for publication Received 24 October 2014; accepted 24 March 2015 Key words ageing; eccentric training; genetics; obesity; strength training Both endothelial nitric oxide synthase (eNOS) gene polymorphism and nitric oxide (NO) are involved in important cardiovascular, muscular and inflammatory physiological mechanisms during ageing and response to exercise. The aim of this study was to investigate the NO kinetic response following an acute eccentric resistance exercise (ERE) session and the possible effect of the Glu298Asp eNOS gene polymorphism in elderly obese women. Eighty-seven women (age 694  61 years, body weight 749  127 kg, height 1519  60 cm and BMI 325  57 kg m 2 ) completed seven sets of ten eccentric repetitions at 110% of the ten repetitions maximum (10RM). NO concentrations remained ele- vated up to 48 h following the acute ERE session as compared with baseline, for GG and GT/TT groups (P<005), with no differences between genotypes. The GG genotype group had higher body weight, prevalence of obesity (BMI classification – 81% versus 56%), BMI and higher relative muscle strength, while they had sig- nificantly lower triglycerides, VLDL and urea concentrations as compared with TT/TG group. In conclusion, NO remains elevated for up to 48 h after an acute ERE session, without genotype interaction. The TT/TG genotype had a negative impact on triglycerides, VLDL and urea concentrations. Thus, T carriers should increase their attention to cardiovascular risk factor and metabolic disorders. Introduction According to epidemiological data, worldwide ageing and lon- gevity have substantially increased, especially in women, who live an average of 7 years more than men (NIDDK, 2001). The ageing process induces changes in body composition, such as increased prevalence of obesity, and loss of muscle mass and strength (e.g. sarcopenia), which is associated with reduced functional capacity to perform activities of daily living and increased mortality (Baker & Cutlip, 2010; Silva et al., 2013). Furthermore, serum and tissue levels of nitric oxide (NO) has been shown to modulate protein synthesis and breakdown (Thomas et al., 2008), possibly interfering in the sarcopenia status of elderly subjects. NO is a signalling molecule responsible for mediating intra- and intercellular processes which regulate several physiological mechanisms (Schmidt & Walter, 1994). It should be noted that some mechanisms may have contrasting effects; for exam- ple, in skeletal muscle, NO participates in both the atrophy and hypertrophy molecular pathways. The main determining factor of NO actions is its concentration (Thomas et al., 2008), and in skeletal muscle the fiber type is also a key fac- tor (Yu et al., 2008). NO plasma and tissue concentrations are highly modulated by rate of production and decomposition (Bian et al., 2006), which are primarily controlled by nitric oxide synthase enzyme (NOS). Although NO has an important protective role in cardiovascular function (Santana et al., 2013), evidence indicates that higher NO levels at rest are present in subjects with metabolic syndrome (Zahedi Asl et al., 2008) and diabetes (Maejima et al., 2001), both disorders that have been associated with increased atherogenic risk. To note, impaired action of NO secondary to its inactivation due to Clin Physiol Funct Imaging (2015) doi: 10.1111/cpf.12255 1 © 2015 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd