Reducing Salt Intake by Enhanced Warning in Family Medicine

Research Article

J Fam Med. 2015;2(2): 1025.

Reducing Salt Intake by Enhanced Warning in Family Medicine

Nina Pinjuh Markota¹ and Mirjana Rumboldt²*

¹Department of Family Medicine, Mostar University School of Medicine, Bosnia & Herzegovina

²Department of Family Medicine, Split University School of Medicine, Croatia

*Corresponding author: Mirjana Rumboldt,Department of Family Medicine, Split University School of Medicine, Croatia

Received: March 26, 2015; Accepted: April 20, 2015; Published: April 22, 2015


Background: Excessive salt intake is a major cardiovascular risk factor. At variance to the developed countries, the main source of sodium in transitional and developing countries is salt added while cooking and/or at the table. The objective of this trial was to examine the impact of enhanced warning on daily salt intake.

Subjects and Methods: A sample of treated hypertensive (N= 150) was randomized in two intervention subgroups, one receiving just a leaflet about the harmful effects of excessive salt intake (N= 74 - group 1), and the other one receiving in addition warning stickers for household salt containers (N= 76 – group 2). Arterial blood pressure (BP) and 24 h urinary sodium excretion (Na24) were measured in all the subjects at the start of the trial, and one month and two months later.

Results: The average starting 24Na was well above 205 mmol. In all the examinees a significant Na24 decrease was observed after 2 months, by some 27 mmol (P < 0.001). The decrease in Na24 was more pronounced in group 2 (to 183 ± 63 and 176 ± 55 mmol; P<0.001) than in group 1 (203 ± 60 and 200 ± 58 mmol; P= 0.147). Moreover, a significant drop in BP, by 5.3/2.9 mm Hg was observed in group 2 as opposed to group 1 (0.4/0.9 mm Hg). Male examinees (N= 73) had significantly higher Na24 during this trial than their female counterparts (N= 77). Decrease in Na24 positively correlated with BP lowering (r² = 0.5989; P< 0.0001).

Conclusions: A significant reduction in Na24 and BP is achieved with educational measures on harmful effects of excessive salt intake, in particular with the respective warning labels. Decreasing daily salt input by 35 mmol may result in an extra BP lowering by some 5-6/2-3 mm Hg.

Keywords: Arterial hypertension; Blood pressure; Family medicine; Risk warning; Salt intake


Excessive salt intake is related to arterial hypertension, which is a major cardiovascular risk factor [1-3]. The worldwide prevalence of arterial hypertension in adult populations is about 30%, representing a major public health issue [4]. Despite numerous effective and affordable antihypertensive drugs, most of the treated hypertensive patients do not achieve satisfactory blood pressure (BP) control; only about a third of treated individuals achieve normal BP values. The causes of unsatisfactory BP regulation are numerous, including inadequate treatment, low compliance, and high salt intake [5].

It is well known that reducing salt intake decreases elevated BP with a number of additional health benefits [1-3, 6-10]. Despite the fact that most hypertensives know about the harmful effects of excessive salt, the salt consumption is still too high. All such patients in a family medicine office, along with the appropriate drugs receive information about the harmful effects of salt, and the ways of its reduction in the daily diet. Unfortunately, these educational efforts leave much to be desired [1-5].

Unlike developed countries, where the main source of salt in the daily diet derives from industrial, processed food (about 75% of the daily intake) [11], in less developed countries the main source of salt is its addition during home cooking procedures and at the table [12-14]. The available data for Croatia show that home cooking and additional seasoning are responsible for 56.4% of salt ingestion, followed by grocery bread (29.8%), and other bakery products (12.8%) [15], with an average daily intake of 10-13 g [16,17]. So far similar data for Bosnia and Herzegovina do not exist.

We have presumed that enhanced warning about the deleterious effects of high salt intake, even in treated hypertensive patients, previously exposed to such information, may cause a further, relevant reduction in daily salt intake and in BP too. We were focused on the main local source of salt, i.e. salt added during home cooking procedures and while eating.

Subjects and Methods

The participants in the present study were consecutive, adult, treated hypertensives of either sex, registered in a family medicine practice in Mostar, Bosnia and Herzegovina [18]. Of the 171 potential examinees, 150 volunteered to take part in the trial (21 did not accept to participate for various reasons) and signed the informed consent form, approved by the Split University School of Medicine Ethics Committee. In individual case report forms recorded were general demographic and anthropometric data, including blood pressure (standard mercury sphygmomanometry) and urinary sodium excretion in 24 hours (Na24). Measurement of Na24 was performed in the University Hospital Mostar Central Laboratory, accepting only samples containing more than 500 ml urine in the appropriately prepared bottles (an inadequate urine sampling had to be repeated in the next few days) [19].

The included 150 participants were further randomized in two groups (sealed envelops), exposed to interventions of varying intensity: group 1 received oral and printed advices on the health benefits of reduced salt intake (clearly stating that any intake over 6 g per day is excessive, while the average intake runs between 10 and 13 g of NaCl per day), and group 2 received moreover especially designed warning stickers to be mounted on all home salt containers (e.g. salt shakers) with an appropriate warning about the harmful effects of excessive salt intake (Figure 1). The participants were individually contacted during office visits (family physician and patronage nurse), when they received the informative leaflet about dangers of excessive salt intake and instructed (group 2) how to put the labels on any (every) salt container.