Inflammatory Response to Salt in Essential Hypertension
|ClinicalTrials.gov Identifier: NCT01665534|
Recruitment Status : Completed
First Posted : August 15, 2012
Last Update Posted : August 15, 2012
|Condition or disease||Intervention/treatment||Phase|
|Essential Hypertension.||Behavioral: High salt intake||Phase 3|
The protocol was in conformity with the ethical guidelines of our institution and informed consent was obtained by each participant. During the run-in phase of the study, which lasted 1 month, patients underwent standard arterial pressure measurements on two separate occasions (at least 10 days apart) and were considered eligible for the study if their casual arterial pressure exceeded 140/90 mmHg.
Patients were randomized to either a 10-20 mmol sodium diet plus sodium tablets (180 mEq/die) to achieve a 200 mmol intake /day, or the same diet plus identical placebo tablets, each for two weeks. At the end of each of these two-week periods, all patients underwent a 24-hours urine collection, a fasting blood sampling and a 24h ambulatory blood pressure monitoring (see below).
Ambulatory monitoring was performed with a device conforming with the AAMI criteria (Takeda 2420 model 7, Takeda Medical, Osaka, Japan). Between 08.30 and 11.30 hours, after placement of the device in the left (non-dominant) arm, the patients rested quietly in an armchair for 15 min and arterial pressure was taken automatically three times (at 5 min intervals). Patients then went home and remained indoors throughout all the recording day. They were instructed to spend a relaxed, quiet day avoiding physical efforts. Recordings were set at 15 min intervals between the 07.00 to 22.00 hours and every 30 min during the sleeping hours (22.00 pm to 07.00). The calibration of the ambulatory recorder was performed against a mercury sphygmomanometer before each recording. Patients were classified as salt-sensitive if the changes in mean arterial pressure between low and high salt diet was > 10%.
Blood sampling was performed on the last day of each period after 45 minutes supine rest. The patients were specifically instructed not to alter their smoking habits, alcohol and coffee intake and not to modify the level of physical activity throughout the study.
Urinary sodium was measured by an ion-selective electrode using a Beckman (Fullertone, CA, USA) EA-2 Electrolyte Analyser. Serum and urine creatinine was measured by a colorimetric method using a COBAS-Mira spectrophotometer (Roche, Basel, Switzerland). The measurements of plasma renin activity (PRA) and plasma aldosterone concentration were performed by radioimmunoassay (RIA) using a commercially available kit (Technogenetics-Milan, Italy).
Biomarkers of inflammation and endothelial integrity/function High sensitivity C-Reactive Protein (hs-CRP) was measured in plasma by a nephelometric method (Dade-Behring, Scoppito, L'Aquila, Italy) (intra-assay CV: 3.5%; inter-assay CV: 3.4%; normal range < 2.87 mg/L). Interleukin-6 (intra-assay CV: 2.6%; inter-assay CV: 4.5%, normal range < 12.5 pg/mL) and TNF-α (intra-assay CV: 4.7%; inter-assay CV: 5.8%, normal range < 15.6 pg/mL) were measured by commercially available RIA kits (R&D System, Minneapolis, USA). High sensitivity procalcitonin (PCT) (intra-assay CV: 2-3% normal value < 0.05 ng/mL) was measured by an immunofluorescence method (Kriptor, BRAHMS, Henningsdorf, Germany). Plasma Adiponectin (intra-assay CV: 3.9%; inter-assay CV: 8.4%) and Leptin (intra-assay CV: 5.0%; inter-assay CV: 4.5%) were measured by a RIA kit (Linco Research Missouri, USA).
|Study Type :||Interventional (Clinical Trial)|
|Actual Enrollment :||32 participants|
|Intervention Model:||Single Group Assignment|
|Official Title:||Procalcitonin and the Inflammatory Response to Salt in Essential Hypertension: a Randomised Cross-over Clinical Trial.|
|Study Start Date :||March 2010|
|Actual Primary Completion Date :||March 2011|
|Actual Study Completion Date :||March 2011|
Experimental: Effect of salt intake
During the high salt intake period, patients received a 10-20 mmol sodium diet plus sodium tablets (180 mEq/die) to achieve a 200 mmol intake /day for two weeks. During the low salt intake period, patients received a 10-20 mmol sodium diet + placebo tablets for two weeks.
Behavioral: High salt intake
During the high salt intake period, patients received a 10-20 mmol sodium diet plus sodium tablets (180 mEq/die) to achieve a 200 mmol intake /day for two weeks
- Change from baseline of inflammatory biomarkers (TNF-alpha, procalcitonin, IL-6, C-Reactive Protein, adiponectin and leptin) in response to salt intake. [ Time Frame: Inflammatory biomarkers were measured at baseline and at the end of two-week diet periods. ]Patients were randomized to either a 10-20 mmol sodium diet plus sodium tablets (180 mEq/die) to achieve a 200 mmol intake /day, or the same diet plus identical placebo tablets, each for two weeks.
- Blood pressure response to salt intake. [ Time Frame: 24h ambulatory blood pressure was measured at baseline and at the end of two-week diet periods. ]Patients were randomized to either a 10-20 mmol sodium diet plus sodium tablets (180 mEq/die) to achieve a 200 mmol intake /day, or the same diet plus identical placebo tablets, each for two weeks.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01665534
|Study Chair:||Carmine Zoccali, Prof.||Nephrology, Dialysis and Transplantation Unit and CNR-IBIM|