Table 1 Detailed description of included studies

Allaert

a randomized, placebo-controlled, double-blind, clinical trial crossover study.

France

58.6(Total)

8 weeks

Stage 2 of hypertension

NaCl + Chitosan 3%

NaCl

149.2/93.4

3

m/f

Blood pressure was measured using homologated automated digital sphygmomanometers.

The BP cuff was placed around the upper left arm which was supported at the level of the heart while the subject sat in a chair. Blood pressure was measured after a 10-min rest and preferably at three different times separated by 3-min intervals. The average of the three measurements was calculated.

Arzilli

Randomized controlled trial

Italy

39.5(Total)

0.25 months

Stage 2 of hypertension

k/Na salt

Common salt [N/A]

> 95

m/f

NS

Barros

Single-blind randomized controlled trial

Brazil

55.5(total participants)

4 weeks

Stage 2 of hypertension

130 mg of sodium, 346 mg of potassium and 44 mcg ofiodine for per gram light salt

390 mg of sodium and 25 mcg of iodine per gram salt

142.95/89.79

5

m/f

Casual BP was measured by the researcher. And home blood pressure use in this study

Gilleran

a randomised blind controlled parallel study.

United kingdom

62.5

3 months

Stage 2 of hypertension and Type II diabetic

50% NaCl, 40% KCL, 10% Mg2+

Ordinary Table salt [N/A]

Sbp = 163.2

NS

m/f

NS

Pereira

randomized, double-blind

Brazil

47.5(Total)

12 week

Stage 2 of hypertension

50% sodium chloride and 50% potassium chloride

NaCl100%

136.2/93.8

4

m/f

Systolic and diastolic blood pressure values during medical consultation were determined by the auscultatory method. Measurements were made with the cuff placed covering the two thirds on the upper arm with the patient sitting, after 5 min at rest, and the values of systolic and diastolic pressure

Sarkkinen

Randomized, double-blind, placebo-controlled

Finland

57

8 week

Stage 2 of hypertension

50% sodium chloride (NaCl), 25% potassium chloride(KCl) and 25% magnesal; magnesium ammonium potassiumchloride, hydrate [Mg4K(NH4)3Cl12·24H2O]

NaCl100%

140/89

4

m/f

BP and heart rate were measured using an automatic sphygmomanometer (Omron M4-I, fully automatic BP monitor, Omron Matsusaka Co, Ltd., Japan) following 10 min rest in a sitting position. BP was measured three times with intervals of at least two minutes, between the hours of 7:00 am and 12:00 noon. BP was measured using the non-dominant arm with the exception of the first study visit during which BP was measured using both arms. If the BP in the two arms differed in SBP or DBP by more than 10 mmHg, the arm with the higher reading was used for all subsequent measurements. Volunteers were not told the results of their BP measurements during the study and the study nurse was unaware of the treatment allocations

Yang (a)

Single blind, randomized, controlled trial

China

67.8

6 months

Stage 2 of hypertension

Low sodium salt [Nacl65%, Kcl30%, Ca salts5% and 12 mg/kg folic acid]

NaCl100%

161/80.6

m/f

SBP and DBP were defined by Korotkoff sound phase 1 and phase 5, respectively.

Yang (b)

Single blind, randomized, controlled trial

China

67.3

6 months

Stage 2 of hypertension

Low sodium salt [Nacl65%, Kcl30%, Ca salts5% and 12 mg/kg folic acid]

NaCl100%

159/85

m/f

SBP and DBP were defined by Korotkoff sound phase 1 and phase 5, respectively.

Zhao

Patient-Blinded Randomized Controlled Trial

China

62.8

3 months

Stage 2 of hypertension

65% sodium chloride, 25%potassium chloride and 10% magnesium sulfate

NaCl100%

174.1/102.2

5

m/f

Blood pressure was measured with three consecutive blood pressure measurements (with at least one minute’s rest between each measurement) from a seated subjects’ right arm in a quiet room. A previously validated electronic sphygmomanometer (OMRON HEM-759P, Dalian China) was used.

Zhou

Single-blind, randomized, controlled trial

China

67.5

6 months

Stage 2 of hypertension

NaCl, 65%;

KCl, 30%;

Calcium saits 5%;

12 mg/kg folic acid

NaCl100%

159.7/83.3

4

m/f

the measurement were performed by two experienced physicians

Zhou

Double-blind, randomized controlled trial

China

46(Total)

24 months

Stage 2 of hypertension

NaCl, 65%;

KCl, 25%;

MgSO4, 10%

NaCl100%

154/91

5

m/f

Blood pressure was measured at each visit by trained doctors using an Omron HEM-770A automatic sphygmomanometer (OMRON (China) Co., Ltd. (OCE/OCE-HCB/OCE-SH), Shanghai, China). Blood pressure was measured in the right arm at the heart level in the seated position.