Aerobic exercise training-induced changes in serum adropin level are associated with reduced arterial stiffness in middle-aged and older adults

Abstract

Fujie S, Hasegawa N, Sato K, Fujita S, Sanada K, Hamaoka T, Iemitsu M. Aerobic exercise training-induced changes in serum adropin level are associated with reduced arterial stiffness in middle-aged and older adults. Am J Physiol Heart Circ Physiol 309: H1642-H1647, 2015. First published September 14, 2015; doi:10.1152/ajpheart.00338.2015.-Aging-induced arterial stiffening is reduced by aerobic exercise training, and elevated production of nitric oxide (NO) participates in this effect. Adropin is a regulator of endothelial NO synthase and NO release, and circulating adropin level decreases with age. However, the effect of habitual aerobic exercise on circulating adropin levels in healthy middleaged and older adults remains unclear. We sought to determine whether serum adropin level is associated with exercise training-induced changes in arterial stiffness. First, in a cross-sectional study, we investigated the association between serum adropin level and both arterial stiffness and cardiorespiratory fitness in 80 healthy middle-aged and older subjects (65.6 Ϯ 0.9 yr). Second, in an intervention study, we examined the effects of 8-wk aerobic exercise training on serum adropin level and arterial stiffness in 40 healthy middle-aged and older subjects (67.3 Ϯ 1.0 yr) divided into two groups: aerobic exercise training and sedentary controls. In the cross-sectional study, serum adropin level was negatively correlated with carotid ␤-stiffness (r ϭ Ϫ0.437, P Ͻ 0.001) and positively correlated with plasma NOx level (r ϭ 0.493, P Ͻ 0.001) and cardiorespiratory fitness (r ϭ 0.457, P Ͻ 0.001). Serum adropin levels were elevated after the 8-wk aerobic exercise training intervention, and training-induced changes in serum adropin level were correlated with traininginduced changes in carotid ␤-stiffness (r ϭ Ϫ0.399, P Ͻ 0.05) and plasma NOx level (r ϭ 0.623, P Ͻ 0.001). Thus the increase in adropin may participate in the exercise-induced reduction of arterial stiffness. ARTERIAL STIFFNESS increases with age (26) owing to declines in endothelial function and autonomic function and increases in arterial wall thickness and calcification (1,3,4,11,18,24,26,31). This functional deterioration impairs the conduit and buffering functions of arteries, leading to several pathological conditions, including hypertension, atherosclerosis, and stroke (1,4,18,26). A cross-sectional study revealed that arterial stiffness was lower in individuals with higher levels of cardiorespiratory fitness (23, 28). Furthermore, habitual aerobic exercise reduces arterial stiffness (10, 28).Adropin consists of 76 amino acids and is encoded by a gene, Energy Homeostasis Associated (Enho) (16), and expressed in multiple tissues, including the brain, heart, kidney, liver, pancreas, skeletal muscle, and small intestine (2, 32). Circulating adropin level decreases with age (7). Recent work showed that adropin is expressed in vascular endothelial cells and promotes nitric oxide (NO) release by regulating endothelial nitric oxide synthase (eNOS) expression via vascul...

Adropin as A Fat-Burning Hormone with Multiple Functions—Review of a Decade of Research

“…Moreover, increased levels of adropin are associated with elevated NOx levels and reduced arterial stiffness. Thus, it is possible that adropin may promote arterial stiffness via NO-dependent signaling [53]. In line with this data, physical exercise upregulates circulating adropin in humans, which is accompanied by improved endothelial function [54].…”

“…Similarly, it was found that adropin enhances insulin signaling and promotes glucose oxidation in mice fed a high-fat diet, which is associated with higher cardiac output [52]. Adropin levels are high after the aerobic exercise-training in humans [53]. Moreover, increased levels of adropin are associated with elevated NOx levels and reduced arterial stiffness.…”

Inverse association between carbohydrate consumption and plasma adropin concentrations in humans

“…Circulating adropin concentrations have been measured in several mammalian species using commercially produced enzyme immunoassays (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22). Human studies have screened for associations between plasma adropin concentrations and cardiovascular disease (5,8,12,17), endothelial function (10,11), type 2 diabetes (T2D) (7,9,14,17), obesity and aging (6), and exercise response (23).…”

Combined aerobic and low-intensity resistance exercise training increases basal nitric oxide production and decreases arterial stiffness in healthy older adults

“…Aerobic training decreases arterial stiffness, (1)(2)(3) an independent risk factor for cardiovascular disease, (4) possibly due to an increase in basal nitric oxide (NO) production. (5)(6)(7)(8) High-intensity resistance training increases arterial stiffness, but low-intensity resistance training seems to have no unfavorable effects on arterial stiffness. (2,9) Combined aerobic and resistance exercise training is often recommended in clinical practice.…”