Short-term effect of dietary-sodium intake on arterial blood pressure of patients treated with systemic corticosteroids: A prospective, randomised, crossover study

Introduction. - It is unknown if the level of dietary-sodium intake influences blood pressure in patients receiving systemic corticosteroids. Methods. - Randomized, single centre, crossover trial involving patients starting systemic corticosteroid therapy and having initial blood pressure less or equals to 159/99 mmHg. The first period of sodium regimen was randomized (< 3 g/j versus > 6 g/j) and each period of sodium regimen lasted 3 weeks. No washout period was performed. Blood pressure was recorded for each patient at inclusion and after 3 weeks and 6 weeks. Moreover, all patients were asked to record on a standardized questionnaire everything they ate during I week of each period regimen. Questionnaires were analysed by a dietician for mean daily energy and sodium intakes during each period. Mixed models were used to estimate the relationship between sodium intake and blood pressure variations. Results. - Between June 2006 and June 2008, 49 patients were randomized, 24 in group 1 (first period regimen = salt < 3 g/day; women: 63%; mean age: 56 +/- 21 years; baseline prednisone dosage: 54 +/- 19 mg/day) and 25 in group 2 (first period regimen = salt > 6 g/day; women: 56%; mean age: 60 +/- 19 years; baseline prednisone dosage: 56 +/- 16 mg/day). Mean daily salt intakes were 2.5 +/- 1.8 and 9.3 +/- 1.9 g/day during the first period and 7.8 +/- 3.2 and 3.8 +/- 2.9 g/day during the second period, respectively for group 1 and group 2. Blood pressure variations were not significantly associated with daily salt intakes or with randomisation group. No order effect was evidenced. By comparison with baseline, systolic blood pressure increased by greater than 20 mmHg at week 6 in five patients (2 in group 1 and 3 in group 2). Conclusion. - At short-term, sodium intake does not seem to influence blood pressure variations in patients starting systemic corticosteroids therapy. (C) 2009 Societe nationale francaise de medecine interne (SNFMI). Published by Elsevier Masson SAS. All rights reserved.