ABC | Volume 113, Nº3, September 2019

Original Article Villela et al. Salt preference and hypertension Arq Bras Cardiol. 2019; 113(3):392-399 seasoning food can change the preference for salt. Another aim was to assess the habitual consumption of sodium and potassium, as well as BP and body mass index (BMI) in the different groups. Methods This was a double-blind experimental investigation in which the sensory parameters were assessed by a convenience sample of 118 untrained tasters from a public healthy center who gave written informed consent to participate. This healthy center is responsible for the secondary care of an area with about 180,000 inhabitants, descendants of diverse ethnicities and coming from many regions of the country.The study was approved by the Ethics Committee of the Faculdade de Medicina de Ribeirão Preto - Universidade de São Paulo (Protocol no. 464/CEPCSE- FMRP-USP; 09/11/2011) and met the guidelines of the responsible governmental agency. Exclusion criteria were: (1) food intolerance, (2) urinary incontinence (3), renal insufficiency, (4) presence of flu, colds, or any oral disease that would affect taste on the day of the experiment, (5) alcohol abuse (intake of more than 14 alcoholic drinks per week), (6) cognitive deficit (7), taking medications that might alter gustatory sensitivity such as chemotherapeutic drugs, penicillin, metronidazole, hydrochloride, amphotericin, nortriptyline, hydrochloride, carbamazepine, biguanide, etambutol, phenylbutazone, fluorouracil, allopurinol, penicillamine, or levodopa; (8) pregnancy (9), and having been submitted to radiotherapy of the head and/or cervical region. After the exclusions, and factoring individuals who refused to participate, four groups of both genders were studied: 32 older hypertensive individuals aged 60 to 80 who were under treatment (OH), 28 older normotensive volunteers aged 60 to 80 years (ON), 25 young hypertensive subjects aged 30 to 50 years (YH), and 33 young normotensive subjects aged 30 to 50 years (YN). The experiments was conducted over 10 consectives months. Procedures The general data of each volunteer were obtained using a semistructured questionnaire, including previous diagnoses, use of medications, smoking status, and alcohol consumption. Weight and height were measured and BMI was calculated for all participants. As a reference of daily sodium and potassium intake, 24‑ hour urinary sodium and potassium excretion was determined on each of the 2 days preceding the experiment. 21 Urine collection started with voiding and discarding the first urine in the morning after waking up. Subsequently, the urine excreted during the next 24 hours, up to and including the first voiding of the following day, was collected. A second 24-hour urine collection was performed 2 weeks later before the second experiment, for futher determination of sodium and potassium excretion. Blood pressure was measured with a semiautomatic instrument (Omron HEM-431 CINT), with 3 measurements on the upper right limb and 3 measurements on the upper left limb after the patients rested in the sitting position for 5 minutes. The measurements were repeated after 2 weeks. On the first day of the experiment, 3 samples of french bread rolls of the same composition except for different amounts of salt were prepared. Salt (1.4%, 2.0%, and 2.7%) was added to each kg. French bread habitually sold in this community contains, on average, 2% salt in its composition. Therefore, we provided a sample of bread with less salt (1.5% salt; 30% less salt than ordinary bread), a sample with the usual percentage of salt (2.0%), and a sample of bread with higher salt content (2.7% salt; 30%more salt than usual bread). The three bread samples were prepared on the day of the test and offered to the volunteers in a random manner in disposable paper bags coded with random 3-digit numbers so that the investigator involved in the test would be unaware of the salt content of each sample. For the tasting, the samples were tested from left to right with a standard size of 10 to 15 g each in order to provide uniformity. The patients drank mineral water at room temperature between samples in order to help remove the taste. At the end of the test, the volunteers, who did not know that the bread samples contained different amounts of salt, were asked to state which sample they preferred. The participants were asked to avoid eating and drinking 2 h before the experiment. In the second experiment, two weeks later, the participants were asked to again taste the 3 samples of french bread containing the same different amounts of salt as in the first experiment (1.5%, 2.0% and 2.7%), but now also containing oregano as an added spice (0.23 g/100 g of bread) and to state their preference. There were no changes in medication between the first and the second tests. Data analysis Firstly, an exploratory analysis of the data was performed. Continuous variables with normal distribution are reported as mean + standard deviation and categorical variables are presented as absolute numbers and percentages. The Fisher exact test was used to compare categorical variables, the McNamer's test was used to evaluate the effect of the intervention and ANCOVA was proposed to compare the groups and to verify the effect of the covariates. 22 This analysis assumes that its residues have a normal distribution with mean 0 and variance σ 2 constant. Transforms were used in response variables that did not reach the assumption. Differences were considered to be statistically significant when p < 0.05. The SAS system (version 9; SAS Institute, Cary, NC) was used for all statistical calculations. Results Gender and alcohol consumption distribution was similar in all groups (p = 0.63; p = 0.26). There was a higher percentage of smokers among young patients than elderly ones (p < 0.001) (Table 1). Urinary sodium excretion was higher in the hypertensive groups (young and older subjects) than in the normotensive groups (young and older volunteers) (p < 0.05) (Table 1), and was higher inmen than inwomen (men: 170.9±73.6mEq/24 h 393