Efficacy of nutritional recommendations given by registered dietitians compared to other healthcare providers in reducing arterial blood pressure: Systematic review and meta-analysis.

INTRODUCTION
The multidisciplinary health practitioners can facilitate adherence to treatment of hypertension. Nutritional recommendations delivered by an expert in nutrition might increase the blood pressure control through a better comprehension about how nutrition plays a role on hypertension.

OBJECTIVE
To evaluate the effect of nutritional intervention performed by a multidisciplinary team with and without registered dietitians compared to usual care in blood pressure control of hypertensive patients.

METHODOLOGY
Systematic review including randomized clinical trials that assessed participants >18 years, both sexes, with blood pressure ≥140/90 mmHg or use of antihypertensive, ≥8 weeks duration and at least one nutritional planned intervention versus usual care. The search was conducted in July 2015 in MEDLINE, EMBASE, BIREME, Web of Science and LILACS without limitation to language. Outcome was defined as deltas of systolic (SBP) and diastolic blood pressure (DBP). Sub-group analysis was conducted according to the presence or not of the registered dietitians in the staff. The analyses were performed in RevMan 5.3 software, using random effects model with heterogeneity assessed by statistical I

RESULTS
From 7280 identified titles, 62 studies were selected for data extraction, and 13 were included in the meta-analysis, with a total of 2050 participants. There was a greater reduction in ΔSBP -2.82 mmHg (95% CI: 4.03 to -1.62) and ΔDBP -1.37 mmHg (95% CI: -2.11 to -0.62) when diet recommendations have been delivered by multi-professional team versus usual care. In stratified analyses only the subgroup of studies with registered dietitians showed statistical significant reduction in blood pressure ΔSBP -3.21 mmHg (95% CI: -4.14 to -2.27); ΔDBP -1.46 mmHg (95% CI: -2.06 to -0.86). There were significant differences between the deltas of blood pressure according to sodium restriction (ΔSBP -3.5 mmHg (95% CI: -4.52 to -2.48), ΔDBP -1.69 mmHg (95% CI: -2.36 to -1, 02)) and caloric restriction (ΔSBP -2.83 mmHg (95% CI: -5.11 to -0.54); ΔDBP -0.92 mmHg (95% CI: -2.21 to 0.37)) only when there was a registered dietitians in the multidisciplinary team.

CONCLUSION
Nutritional recommendation made by multidisciplinary team has a statistical significant effect on blood pressure control in hypertensive patients, mainly when a registered dietitian is present in the team.