The association of plasma resistin with dietary sodium manipulation, the renin-angiotensin-aldosterone system, and 25-Hydroxyvitamin D3 in human hypertension

P>Objective Both resistin and vitamin D have been associated with the renin-angiotensin-aldosterone system (RAAS). We investigated the association between resistin and the RAAS, and resistin and vitamin D under controlled dietary sodium conditions. Design Retrospective cross-sectional study of subjects from the HyperPATH Consortium, who were maintained in high dietary sodium (HS) and low dietary sodium (LS) balance for 1 week each. Patients Caucasian subjects with hypertension (n = 177). Measurements 25-hydroxyvitamin D (25[OH]D) levels were used to assess vitamin D status. Plasma resistin and RAAS measures were evaluated on each dietary intervention. Results Resistin levels were significantly higher in LS, where RAAS activity was high, when compared with HS balance, where RAAS activity was suppressed (6 center dot 36 vs 5 center dot 86 mu g/l, P < 0 center dot 0001); however, resistin concentrations were not associated with plasma renin activity or serum aldosterone on either diet. 25(OH)D levels were positively and independently associated with resistin in both dietary conditions (HS: beta = 0 center dot 400, P-trend = 0 center dot 027; LS: beta = 0 center dot 540, P-trend = 0 center dot 014). Conclusions Dietary sodium loading reduced resistin levels, possibly by suppressing the RAAS; however, circulating RAAS components were not related to resistin concentrations within each specific dietary sodium condition. 25(OH)D was positively associated with resistin and may be involved in resistin regulation through an unknown mechanism. Further studies to understand resistin regulation in human hypertension better are warranted.