Topic: Physiology - Hyperuricemia and artery health
Aim: To observe the effects of Hyperuricemia and high uric acid in the blood on the core organs in our bodies.
Research question: To what extent will the concentration of uric acid (0%, 20%, 40%, 60%, 80%, 100%) that the aortas are exposed to
influence the permeability rate, and hence, the weight of the artery, revealing the effects of Hyperuricemia on the body?
Personal engagement:
My father is a doctor, and ever since I could recall, I would try to eavesdrop my father's discussions with the other doctors as I was always
fascinated by the way he talked about the treatment of his patients. Additionally, I remember annoying him with the number of questions that
I had regarding the human body. Why do we sweat when we perform intense physical activities? What happens to the food after we swallow
it? How is food digested in our body? Why do we always have to ensure that we are drinking enough water?
Fortunately, my father was very patient and he always welcomed my questions with open arms. When I grew up, I learned that every doctor
had a specialization, and I later learned that my father was a consultant urologist. Through research in his field, I found out that Urology is the
medical branch that focuses solely on surgical diseases associated with the human urinary tract (Watson, 2018). At that age, my knowledge
was very limited to the organs in our body, hence, I was unsure about what the urinary tract was. Now even with me being more educated on
the human body, I believe that my knowledge on urology is still limited. Hence, I dedicated this investigation to Urology as this will be an
opportunity for me to explore thoroughly in my father's field. In this experiment, I will proceed to discover the effects of some of the diseases
in the urinary tract that are treated by urologists on the organs in our body; Hyperuricemia.
Background information:
Uric acid has the chemical formula of C5H4N4O3 ("Uric acid," 2020). It is a heterocyclic compound that belongs to the purine group, created
1 2
by the enzyme xanthine oxidase. 3
Purines are exogenous where they are found in food and drinks and 3
purines are endogenous where they
are produced by the human body (Gabbey, 2020). Uric acid levels in the blood are controlled to avoid and minimize its damaging effects.
Usually, uric acid is eliminated in the kidneys, to ensure that its concentration is kept at a healthy level in the blood (approximately 300
microM) (Hedger, 2004). High plasma uric acid in the bloodstream usually occurs when the uric acid is not eliminated efficiently by the
kidneys. Factors that may influence this slowing down include: a diet high in purine-containing items, such as red meat and some seafood,
diabetes, inherited tendencies, underactive thyroid, alcohol, and being overweight ("High uric acid level causes," 2018).
The kidneys play an important role in the human body, in which it performs crucial functions. Its jobs include filtering the blood, removing
toxins and wastes, controlling the body's fluid balance, and maintaining the levels of electrolytes, help make red blood cells, and help control
blood pressure (National Kidney Foundation, 2020). All of the blood in the human body passes through them several times a day. The
kidneys are made up of filtering units called nephrons, each of which contain its own set of structures; the glomerulus, and a tubule (Jewell,
2018). This organ works in a two-step process: ultrafiltration (glomerulus); tubular filtration (nephrons) (NIDDK, 2018).
Kidney (renal) failure is when the kidneys in one’s body stop functioning as they should, and more specifically when it loses the ability to
sufficiently filter waste from the blood. Causes of kidney failure include: sudden loss of blood flow caused by a heart attack or heart disease,
urine elimination problems, chemotherapy drugs, and a blood clot in or around kidneys (The Healthline Editorial Team, 2019). When the
kidneys are no longer able to filter the blood, it can cause levels of waste products and extra fluid to build up, and the body becomes
overloaded with toxins (Better Health Channel, 2018). Additionally, when the kidney stops working, Uremia occurs. The condition - Uremia-
occurs when a person reaches the final stages of chronic kidney disease (CKD). Problems such as fatigue, loss in appetite, and leg cramps are
caused by waste products that build up in the blood.
Normal Uric acid levels range from 2.4-6.0 mg/dL in females and 3.4-7.0 mg/dL in males (Skeete et al., 2019). However, these levels can
vary with blood pressure, body weight, renal function and alcohol intake (Chemocare.com, n.d.). Normal uric acid levels in the urine range
from 250 to 750 milligrams (Gabbey, 2020). Excessive amounts of uric acid leads to Hyperuricemia. This condition is a factor of developing
gout. Gout is a form of arthritis and a rheumatic disease caused by excessive uric acid levels in the bloodstream (McIntosh, 2017). While
Hyperuricemia is a risk factor for gout, ⅔ of patients with Hyperuricemia remain asymptomatic, however, the risk will increase as uric acid
levels increase. In this manner, patients with uric acid levels that ranges between 7.0 (416 μmol/l) and 8.0 mg/dl (475 μmol/l) have an
accumulated risk of 3% of developing gout, while patients with uric acid levels of 9.0 mg/dl (535 μmol/l) or more have a risk of 22%
(Álvarez-Lario & MacArrón-Vicente, 2011).
Moreover, some studies have shown that this condition is also a risk factor of developing other diseases as discussed below.
A study (Moe et al., 2005, p. 1606-1609) has deduced that Hyperuricemia plays an important role in the formation of calcium oxalate stones,
where the presence of these stones indicates that there is an increased urinary discharge and decreased excretion of citrate. Additionally, the
incidence of stone formation in primary gout varies with the uric acid excretion rate (Álvarez-Lario & MacArrón-Vicente, 2011).When uric
, acid levels are typical, the incidence of stone formation ranges from 10% to 20%, while on the other hand, when uric acid levels are high
(renal discharge of uric acid surpasses 1000mg/day), the incidence of stone formation ranges from 40% to 50%.
Another potential risk Hyperuricemia may cause are heart issues. A study has shown that elevated uric acid levels increase the risk for arterial
disease, where it occurs in about 51% of all patients with high uric acid levels. This activation of the platelet activity may be directly related
back to the uric acid levels. It is proposed that Hyperuricemia is a thrombotic risk factor, where the platelet may be a prime reactant linking to
the high uric acid (Bluhm & Riddle, 2004).
Since the 1850s, Hyperuricemia and the coronary artery disease have been associated. Investigators reveal a trend between the two, showing
that a higher uric acid level was associated with higher incidents of the three-vessel disease in women. The-three vessel disease is the most
severe form of atherosclerosis - the buildup of plaque restricting blood flow (Min Li et al., 2016). Hyperuricemia is associated with
established cardiovascular risk factors, such as obesity, atherosclerosis, and high blood pressure (Lan et al., 2018).
Contrastingly, some epidemiological studies have shown that high uric acid levels are not an independent risk factor that leads to
cardiovascular diseases. The reason for the difficulties of these epidemiological studies to establish a direct correlation between uric acid
levels and cardiovascular diseases is due to the association of uric acid concentrations with other risk factors such as chronic kidney disease,
hypertension, diabetes, and smoking. For instance, numerous studies have supported the correlation between uric acid and cardiovascular
diseases, where their findings showed that higher uric acid levels was related to the risk of cardiovascular mortality in individuals with type 2
diabetes (Chang et al., 2018). However, the reduction of uric acid concentrations might not necessarily result in the reduction of
cardiovascular mortality. While there was some sort of relationship between the two, an experiment using the logistic regression showed no
independent association between Hyperuricemia and the coronary artery disease nor its severity (Lan et al., 2018). Therefore, the ability of
previous studies have been very limited to establish a clear observation of the role of uric acid in cardiovascular diseases (Chang et al., 2018).
While Hyperuricemia has negative influences on the human body and seems to be associated with other diseases, these elevated uric acid
levels also seem to have positive influences, and an important role in many biological functions in the human body.
Red blood cells are considered as one of the most abundant cells in the human body, where it contains uric acid however, it lacks organelles,
DNA, and the machinery required for protein synthesis. In spite of the fact that uric acid contributes to the radical-scavenging antioxidant
limit of the plasma, the function of uric acid for red blood cells is indistinct. A study investigated the correlation between uric acid levels and
red blood cell parameters in the patients’ blood to observe whether or not uric acid could lessen the oxidative stress injury, several parameters
were measured in the study. The simple correlation linear analysis revealed a significant correlation between Uric acid and mean corpuscular
hemoglobin, mean corpuscular hemoglobin concentration, mean corpuscular volume, red blood cells, and hemoglobin levels. In addition to
this type of analysis, the multivariate linear regression analyses confirmed the positive relationship between uric acid levels with hemoglobin
and red blood cell counts (Song et al., 2019).These results were very similar in both gender subgroups. Furthermore, health patients with low
uric acid levels have displayed a higher reactive oxygen species contrasting to those patients with high uric acid levels. This has, therefore,
prompted the suggestion that higher uric acid levels protect typical red blood cells against cellular aging. Uric acid was able to shield Red
blood cells against modification and from oxidative modification of proteins, as well as prevent carbonyl groups build-up. Those protective
effects of uric acid can be attributed to its direct antioxidant activity, extinguishing free radicals and reactive oxygen species. Uric acid may
maintain the smooth membrane surface of red blood cells, hence resulting in the prevention of echinocytes and spherical Red blood cells
formation (Song et al., 2019). All in all, this study has revealed a significant positive correlation between uric acid levels with Red blood cell
counts and hemoglobin concentrations. This study has shown that uric acid plays a beneficial role in Red blood cells longevity.
Results of a study (Li et al., 2015) revealed a positive correlation between the uric acid levels and the prevalence of vulnerable atherosclerotic
plaque, where the composition of artery epithelium reacts to acidic conditions, forming atherosclerosis due to the inflammatory response.
There were no significant observations about the interactions between Uric acid levels and sex, diabetes, obesity in relation to the plaque
vulnerability (Li et al., 2015).
With all of these studies investigating the numerous effects that elevated uric acid levels have on the body and its association with different
cardiovascular diseases, this investigation will aim to observe and explore the effect of Hyperuricemia on the heart. This will be achieved by
investigating the damage made on epithelium tissues by uric acid.Blood vessels that carry oxygenated blood to the organs of the heart are
known as the coronary arteries. The heart is one of the core organs in our bodies, and is in need of a continuous supply of oxygen to function
properly, similar to any other organ of the body which needs oxygen to survive. The coronary arteries surround the entire heart, and it
transports the oxygenated blood to the heart muscles. The two main branches which supply the heart with oxygen, are the left coronary artery
(LCA) and the right coronary artery (RCA) (Cleveland Clinic, 2019). The largest artery in the body that transports oxygenated blood to the
rest of the body is the Aorta (Cleveland Clinic, n.d.). The solution that will be used to discover the effects of Hyperuricemia is synthesized
uric acid, and the artery that will be exposed to this solution is the aorta.
