DIETARY INTAKE AND BLOOD PRESSURE OF ADULTS IN IKWUANO LGA, ABIA STATE

             

 Blood pressure is the pressure that circulates blood on the walls of blood vessels (World Health Organization (WHO), 2006). Most of this pressure is due to work done by the heart by pumping blood through the circulatory system. Used without further specification, “blood pressure” usually refers to the pressure in the large arteries of the systemic circulation (Blood Pressure Association (BPA), 2008).

Blood pressure is usually expressed in terms of the systolic pressure (maximum during one heartbeat) over diastolic pressure (minimum in between two heartbeats) (BPA, 2008). Normal resting blood pressure in an adult is approximately 120 millimeters of mercury (16kPa) systolic, and 80 millimeters of mercury (11kPa) diastolic, abbreviated as “120/80mmHg”(Mbah et al., 2013). Globally, the average blood pressure, age standardized, has remained about the same since 1957 to the present, at approximately, 127/79mmHg in men and 122/77mmHg in women (Kannel, 1996).

 A high fall in blood pressure is known as hypotension. It is a medical concern if it causes signs or symptoms such as dizziness, fainting, or in extreme cases, circulatory shock. It is characterized by a persistent systolic/diastolic blood pressure decrease of >20/10mmHg (Ogedegbe and Pickering, 2010).  

On the contrary, hypertension occurs when there is excessive pressure against the blood vessel walls (Kannel, 1996). A certain amount of pressure is required to keep the blood flowing throughout the body (Ibekwe, 2015). However, if blood pressure is always high, then the lining of the blood vessels can be damaged (Mbah et al., 2013). Hypertension is a chronic disease which has been reported to be common mostly among elderly and young adults and it is an emerging health problem in semi-urban areas in Africa and Nigeria inclusive (Yameogo et al., 2012, Mbah et al., 2013, Adediran et al., 2013). It is the single most important cause of death worldwide and the second major cause of disability next to childhood malnutrition (Lopez et al., 2006). Consistent blood pressure readings of 140/90mmHg indicates the presence of high blood pressure (Kannel, 1996).

Dietary intake refers to the daily eating patterns of an individual, including specific foods and calories consumed and relative quantities (Piana, 2001). Dietary pattern of an individual reflects the type and amount of foods consumed together (Appel et al., 1997). It accounts for the cumulative effect of foods and nutrients (Appel et al., 1997). Inappropriate eating habits and frequency of the foods taken coupled with unhealthy lifestyles has predisposed many people to hypertension (Ibekwe, 2015).

Hajjar et al. (2001) suggested that changes in blood pressure can be modified by dietary intakes. Consistent with previous studies, blood pressure and dietary intake are associated less strongly than blood pressure and BMI (Ascherio et al., 1992; Kannel, 1996; Wassertheil-Smoller and Lamport, 1990).  Appel et al. (1997) study showed that certain dietary intakes can favorably affect blood pressure in adults with average systolic blood pressures of less than 160mmHg and diastolic blood pressure of 80 to 95mmHg. Specifically, a diet rich in fruits, vegetables and low-fat dairy products and with reduced saturated and total fat lowered systolic blood pressure by 5.5mmHg and diastolic blood pressure by 3.0mmHg (Ascherio et al., 1992).

Furthermore, a reduction in high blood pressure due to dietary intakes was similar in magnitude to that observed in trials of drug monotherapy for mild hypertension (Svetkyet al., 1999b). Hence following a well-developed and modified dietary regimen might be an effective alternative to drug therapy in people with stage 1 hypertension (Appel et al., 1997). In this regard, it is therefore evident that non-pharmacologic approaches to decrease blood pressure at a population level are required to curb the predicted escalating increase in the rate of hypertension.

Hypertension is estimated to affect about one billion people worldwide and is a major risk factor for many cardiovascular diseases (WHO, 2013). Cardiovascular diseases are responsible for about 17 million deaths globally, with complications from high blood pressure resulting in about7.5 million deaths and 57 million disability-adjusted life years (DALYs) worldwide, both accounting for about 12.8 and 3.7% of global deaths and DALYs, respectively (WHO, 2013; Kaerney et al., 2005). Nigeria, currently with a population of over 160 million, is the most populous African country (World Bank, 2013), and the prevalence of hypertension in the country hugely contributes to the overall burden in Africa (WHO AFRO, 2005). 

However, the prevalence reduced in 2014 with an estimated prevalence ofhypertension of 28.9% was reported for adults in Nigeria (Adeloye et al., 2014). This is believed to be due to an increasing adult population, rapid urbanization and uptake of western lifestyles, including high consumption of processed foods (with high salts and fats), tobacco and alcohol products (Bello, 2013; Mezue, 2013). The 1997 Nigerian National NCDs survey committee reported a hypertension prevalence of 11.2% in both sexes, which was then about 4.33 million hypertension cases in people aged above 15 years (Akinkugbe, 1997). This survey could have underestimated the prevalence of hypertension in Nigeria, as the diagnosis was based on the old definition of hypertension (160/95mmHg) (Bello, 2013). From the 2003 national NCDs survey conducted mainly in the south-west region, which was based on SBP at least 140mmHg and/or DBP at least 90mmHg, the overall prevalence of hypertension was 28.9% (Adeloye et al., 2015). In addition, recent surveys in various parts of Nigeria based on at least 140/90mmHg have also shown a higher prevalence of hypertension, ranging from 25.0 to 36.6% (Mezue, 2013).  Research has also indicated that blood vessels naturally harden with age, losing their elasticity. This may be one explanation for why older people/ adults are more at risk of developing high blood pressure (Xu et al., 2017). 

One major problem affecting the response to this burden in Nigeria is that the awareness, treatment and control of hypertension have been low (Kayima et al., 2013). Consequently, many who live with high blood pressure end up in health facilities with cardiovascular complications, including heart failures, ischemic heart disease and strokes (Ogah et al., 2012) In fact, research findings show that high blood pressure is diagnosed in many people as an incidental finding when admitted for unrelated ailments (Perkovic et al., 2007). This obviously has resulted in high morbidities and mortalities from hypertension in Nigeria (DeGraft et al., 2010) and reports still show that there is yet to be a nationwide measure to facilitate regular screening and detection of high blood pressures (Bello, 2013). Additionally, there is also a high economic burden as a consequence of hypertension and associated cardiovascular complications in Nigeria (Abegunde et al., 2007). This is demonstrated by direct costs, for example: the cost of antihypertensive medications, administrative fees, laboratory fees and other out-of-pocket health expenditures, and indirect costs, such as: loss of savings from repeated healthcare expenses, hospital waiting times and work absenteeism (Ilesanmi et al., 2012). The burden of hypertension in Nigeria is high and still growing (Bello, 2013), and we still cannot say with certainty the exact burden. There is therefore a need for serious intervention strategies in order to control this silent killer disease.

The incidence and severity of hypertension are affected by nutritional status and dietary intake (Hajjar et al., 2001). Studies have also shown that excessive weight gain, salt intake, smoking of cigarettes, drinking of alcohol and physical inactivity are the major predisposing factors for hypertension (He, 2013; Law et al.,.1991; Ijarotimi and Keshinro, 2008; Olaitan et al., 2018). It is therefore evident that dietary intake, dietary pattern and lifestyle of an individual are important elements in preventing, managing and treating hypertension (Olaitan et al., 2018; Ijarotimi and Keshinro, 2008). Nevertheless, few studies are available yet regarding the relationship between dietary intake and blood pressure in Africa, especially in Nigeria, thus creating an insight in this area is of great importance.

The general objective of this study is to evaluate the relationship between dietary intake and blood pressure of adults in Ikwuano LGA of Abia state.

The specific objectives include to:

Identifying the dietary intake and blood pressure of adults would help provide an insight to health care professionals, the government, the mass media and most importantly the masses on how nutrient intake can contribute negatively or positively to blood pressure. Results from this research would help them appreciate the importance of consuming adequate diets. If found necessary, it will serve as a source of reference to other researchers, nutritionists, dieticians, institutions and public health workers working to improve the health status of hypertensive patients as well as the general public and to advocate for resources for targeted interventions on improving domestic food production. It can be used by government ministries and other private sector organizations to evaluate local production and food distribution systems for increasing diversity of food supply. It can also be used by policy / programme decision makers to formulate national policies and evaluate fiscal and trade policies to enhance nutrition and well-being.