**1. Introduction**

Chronic diseases are long-lasting conditions with continuous e ffects, and include cardiovascular disease (CVD), chronic respiratory disease (CRD), cancer and type 2 diabetes (T2D). Globally,

their incidence is increasing becoming a growing burden to global economies and people's quality of life. Collectively, these non-communicable diseases (NCDs) are the leading cause of death globally [1], making it a significant priority in healthcare systems. In some countries, up to 40% of those dying from NCDs are younger than 60 years of age [1].

The rapid improvement in the socio-economic status of the countries making up the Gulf Cooperation Council (GCC) (Bahrain, Kuwait, Oman, Qatar, Saudi Arabia and the United Arab Emirates (UAE) has contributed to changing food consumption patterns, lifestyle habits and health status over the last four decades, with diet quality decreasing through the addition of more processed Westernized food. These changes have resulted in an increasingly sedentary lifestyle, high blood pressure and obesity, known to be major risk factors of NCDs [2,3]. Thus, it is not surprising that CVD is the major cause of morbidity and mortality in the Gulf region [4]. It is estimated that NCDs cause between 65% and 78% of deaths in the GCC member countries [5].

In particular, the lifestyle of the Emirati population has changed considerably in the last 40 years due to rapid improvement in socio-economic indicators in the UAE. This transition has led to less physical activity and altered eating habits, including increased intake of processed foods. These changes, in addition to the adoption of a Western lifestyle and diet, have led to the rise in prevalence of overweight, obesity and the risk of metabolic syndrome in the UAE. In the UAE, CVD accounts for more than 25% of all deaths countrywide, however, this has increased in the major metropolitan center, accounting for 29% of all deaths in the Emirate of Abu Dhabi [6].

Diet, environmental factors, lifestyle, physical inactivity and genetics have been shown to contribute to the risk of NCDs [1]. Control of these primary risk factors could reduce the incidence of some NCDs by up to 80% and cancers by 40% [1]. As such, in recent years, there has been a significant effort to improve diet and increase physical activity to control the prevalence of NCDs. Hypertension is the most common outcome of excessive sodium intake independent of age and is a key risk factor for many NCDs [7]. Globally, over 7.5 million people die from hypertension-related complications per year, which surpasses deaths from tobacco smoking (5 million), obesity (2.8 million) and cholesterol (2.6 million) [8]. Hypertension, secondary to excessive salt consumption, is a major risk factor for CVD, responsible for 62% of strokes and 49% of coronary heart disease (CHD) [7]. In the UAE, approximately 30% of the population is hypertensive, [9] and the disease is thought to be widely underdiagnosed [10]. High salt intake is considered one of the major contributors to premature adult death in developed and developing countries [11]. A systematic review and meta-analysis of 5508 participants across 61 studies showed that higher salt intake was associated with significantly increased risk of stroke, stroke mortality and coronary heart disease [11]. Unfavorably high sodium intake remains prevalent worldwide and varies widely, ranging from 4–17 g/day, with mainland China having the greatest intake, and some less developed island nations the lowest [12], but for many countries it remains well above the World Health Organization (WHO) recommendation of less than 5 g of salt intake per day [13]. The UK Food Standards Agency highlighted in 2012 that 75% of salt intake comes from processed foods and proposed that a reduction in the sodium content of processed food and drink would be required to achieve the recommended daily intake in the community [14,15].

Alongside appropriate sodium consumption, ensuring adequate intake of potassium is vital to ensuring normal mineral homeostasis and healthy blood pressure. Potassium is the paired ion for sodium in a range of di fferent physiologies—from nerve transmission to renal function. Having adequate potassium in the diet ensures that the kidney is able to remove sodium from the plasma, and hence allows more e ffective regulation of blood pressure. While frank potassium deficiency (hypokalemia) is well understood and monitored, chronic, insu fficient dietary intake is not, despite being associated with an increase in systolic blood pressure, and in the face of declining diet quality, insu fficient intake is becoming more common [16]. Despite its important role in health, potassium intake has not been investigated in the UAE, however, globally, it has been reported that there is widespread dietary insu fficiency, and this is likely to be mirrored in the Gulf region.

The impact of diet on NCDs is critical, and dietary approaches such as the Mediterranean diet have been suggested to have a role in improving health outcomes globally. The Mediterranean diet, with its high fruit and vegetable and low meat and processed food content, is an e ffective way to reduce salt and sodium intake, leading to a subsequent improvement in health outcomes [17]. Its high vegetable content also lends itself to improving potassium intake—making it an e ffective intervention to reduce hypertension [17].

There are numerous methods used for assessing salt intake, including estimation by weighing ingested food, dietary recall questionnaires, estimating the salt content of food before ingestion and taking measurements of 24-h (hr) sodium excretion [18]. Measurement of 24-h urinary sodium excretion is considered to be the golden standard for estimating daily sodium intake on the premise that the majority (90–95%) of sodium ingested is excreted via the urine [18].

The aim of this study was to assess sodium intake using 24-h urinary sodium excretion from a sample of the healthy UAE population and to assess their knowledge, attitudes and practices (KAP) surrounding salt intake.

#### **2. Materials and Methods**

#### *2.1. Study Design and Participants*

A cross-sectional study with an anonymized self-reported questionnaire and the collection of 24-h urine for the assessment of sodium, potassium and creatinine excretion was conducted between March 2015 and June 2015 in the UAE. The questionnaire consisted of items to assess participants' attitudes, behavior and knowledge (KAP) regarding salt consumption and knowledge. The sample size was calculated based on the following formula to be representative of the UAE, with a confidence interval level of 95%.

Sample size of an unknown population was calculated by Cochrane's formula (n = z2 × *p* × (1 − *p*)/e2), with z = level of confidence (for a level of confidence of 95%, z = 1.96); *p* = the estimated proportion of the population that presents the characteristic of having high knowledge *p* = 0.5; e = margin of error accepted, e = 0.05; N (sample size) = 385 participants, plus 20% estimated dropouts = approximately 461 participants. Hence, a sample of 530 healthy individuals were recruited to participate in the study from the seven Emirates (Abu Dhabi, Dubai, Sharjah, Ajman, Ras Al Khaimah, Fujairah and Umm Al Quwain) aged between 20 and 65 years. Two methods were used for recruitment: face to face recruitment at community, school or university events and posters displayed in shopping malls, health centers, schools and university hostels. The WHO/PAHO (2010) protocol for 24-h urine collection and analysis was used. Four age groups were considered for recruitment in the current study; 20–30, 31–40, 41–50 and 51–65 years old with a ratio of 1:1 male to female. This demographic was used to ensure a sample of the 'healthy' population—participants older than 65 are likely to have comorbid disease which may have a ffected the urine analysis. All participants provided written informed consent to participate in the study.

A screening questionnaire was designed to collect data regarding demographic information, lifestyle habits, past medical history, medication and current health status. Questionnaires were administered by the research team. Exclusion criteria at screening were those with self-reported chronic diseases (i.e., heart disease, using medication for hypertension, renal failure, liver disease), pregnan<sup>t</sup> and lactating women, those on diuretics and women who had their menstrual period during the time of urine collection. Inclusion and exclusion criteria are summarized in Table 1. Inclusion criteria at screening were participants aged 20 to 65 years for both genders, non-pregnan<sup>t</sup> and non-lactating, no known chronic kidney disease, renal failure, hypertension with medications and liver diseases, no medical condition(s) or medication(s) known to a ffect urination and able to collect 24-h (hr) urine. Exclusion criteria following urine collection included those that were unable to collect adequate urine within the 24-h time period (i.e., volume < 500 mL), and creatinine levels below 500 or above 2000 mg/day, which is equivalent to <9 or >26 mg/kg of body mass for female participants and <13

or >29 mg/kg of body mass for male participants [19]. Forty-one participants were excluded due to limited urine sample collection (<500 mL urine) or being unable to e ffectively urinate into the collection bottle, and 12 participants due to creatinine levels below 500 mg. The creatinine cuto ffs were used to screen for renal abnormalities that may have skewed the results [19]. One urine sample was also excluded during testing due to abnormalities, leaving 476 urine samples for the final urine analysis, alongside 477 questionnaire responses. The enrolment process of the study participants is shown in Figure 1.

**Table 1.** Summary of inclusion and exclusion criteria.

**Figure 1.** Flow diagram of the study design.

Participants were given full details of the study protocol with the opportunity to ask questions after which written informed consent to participate was sought. Each participant was allocated a personal identification number to provide anonymity and data confidentiality. Ethical approval for the study protocol was obtained from the UAE University (UAEU) Scientific Research Ethics Committee (Reference number: DVCRGS/36/2015).
