High salt intake fails to enhance plasma adiponectin in normotensive salt-sensitive subjects

Evidence shows that salt can modulate adiponectin and inflammation levels in normal individuals. Therefore, we hypothesized that abnormalities in adiponectin and inflammation might be the potential mechanism of salt sensitivity. The aim of this study was to investigate whether different alterations of adiponectin and inflammation levels in response to a high-salt intake were exhibited between normotensive salt-sensitive and salt-resistant subjects.

Thirty normotensive subjects (25 to 50 y old) were selected from a rural community of northern China. They were sequentially maintained on a normal diet for 3 d at baseline, a low-salt diet for 7 d (NaCl 3 g/d), and then a high-salt diet for 7 d (18 g/d).

Salt sensitivity was diagnosed in 10 subjects who exhibited an increase of at least 10% in mean blood pressure from the low-salt to the high-salt periods. Plasma adiponectin was significantly higher with the high-salt intake than with the low-salt intake (6.1 ± 1.3 versus 7.1 ± 1.7 μg/mL, P = 0.047) in normotensive salt-resistant subjects but not in the normotensive salt-sensitive subjects (6.4 ± 2 versus 5.9 ± 2.1 μg/mL, P = 0.481). The high-salt intake markedly increased plasma tumor necrosis factor-α (P < 0.0001) and monocyte chemoattractant protein-1 (P < 0.0001) in normotensive salt-sensitive and salt-resistant subjects. No significant change in plasma high-sensitivity C-reactive protein was observed.

Our data indicate that the disturbance of adiponectin exists in normotensive salt-sensitive subjects during a high-salt diet, which may be a novel underlying mechanism of salt sensitivity.