Diabetes Mellitus and Chronic Kidney Disease
By Annetta Bays
Mount Carmel College of Nursing
According to Healthy People 2020, diabetes mellitus and chronic kidney disease affects more than 20 million people in the United States alone. Diabetes is the leading cause of chronic kidney disease and once nephropathy occurs, the decrease of renal function begins. This report will attempt to cover several aspects of diabetes mellitus and its effects in the human body. Chronic kidney disease is strongly affiliated with diabetes mellitus and will be discussed in depth. Several studies will be discussed with their findings along with indicators to monitor and recommendations to suggest to your endocrinologist or family physician.
Diabetes mellitus is a group of metabolic diseases that affects insulin secretion and results in high blood glucose levels. There are two types of diabetes mellitus, insulin dependent (type 1) and non-insulin dependent (type 2). Type 1 diabetics depend on external insulin for survival and type 2 are insulin resistant but almost half may require external insulin to maintain blood glucose control (Williams, 2003). Insulin decreases blood glucose levels by increasing the use of glucose (for energy), promoting the storage of excess glucose, and decreasing energy production of other food sources (Williams, 2003). Insulin is a natural product of the human body and is produced in the pancreas. The pancreas is a gland that also secretes digestive enzymes and hormones. These hormones control the glucose levels in the body. The enzymes and hormones are triggered as food enters the upper digestive tract. The pancreas secretes the enzymes to break down fats, proteins, carbohydrates, and nucleic acids (Baggaley, 2001).
Today more and more people are being diagnosed with diabetes mellitus. Education and self-care can prevent or delay complications and diabetics can lead full and productive lives. But, no one person is immune to this disease. Some risk factors include being over the age of 45; being overweight; being of African-American, Hispanic, Native American, or of Asian descent; having other family members with diabetes (as this disease can be genetic); and having high blood pressure.
Obesity, being a risk factor that can be modified, is a large factor for diagnosis of diabetes mellitus. Today’s society has been packing on the pounds with ‘super-sizing’ meals. The human body is a fine, well-oiled machine. Fuel (food) is needed to survive but most people make unhealthy choices. People need to start educating the younger generation about the dangers of over-eating and the lack of activity. The general population needs to get up off the couch, go for a walk, ride a bike, shoot some hoops; just get up and get active!
Insulin and Its Effects on the Human Body
There are several types of insulin and administrations for insulin to be entered into the body. Insulin is easily digested if taken orally so most forms are injected subcutaneously. Glucagon and insulin are the hormones produced in the delta cells of the pancreas called the islets of Langerhans. The insulin helps the body store excess glucose, while glucagon raises the blood glucose levels to use for energy. Insulin working together with the glucagon helps to maintain the blood glucose at a constant level in the body. Without glucose control, serious complications occur gradually. Most are painless so they are not detected until in the later stages, after the destruction has been done and has progressed past the point of reversal or correction.
The kidneys assist the human body in maintaining chemical balance by eliminating waste and excess fluids. Each one of the two kidneys contains approximately one million filtering units that strains waste products from the blood for excretion. The kidneys also provide equally important functions such as the regulation of blood volume, electrolyte balance of the blood, and acid-base balance of the blood. This process assists in the maintenance the normal composition, volume, and pH of blood and tissue fluid (Williams, 2003). The blood’s main blood vessel, the abdominal aorta, branches off to the renal arteries then branches again within the kidneys into multiple progressively smaller blood arteries. From these smaller arteries comes afferent arterioles in the renal cortex then into glomeruli (capillaries), to efferent arterioles, to peritubular capillaries, to veins in the kidney, to the renal veins, and finally to the inferior vena cava. During this pathway, there are two sets of capillaries that exchange the blood and the surrounding tissues. The capillaries of the kidneys are where the exchange takes place forming urine from blood plasma. To form the urine, three major processes need to occur; glomerular filtration in the renal corpuscles, tubular reabsorption, and tubular secretion. The kidneys are also important in the production of new red blood cells. Erythropoietin is secreted by the kidneys, which stimulates the production of red blood cells in the bone marrow.
Complications from Diabetes Mellitus
Diabetes mellitus is a very serious disease with complications such as blindness, kidney failure, heart attack, and stroke (Williams, 2003). Persons with diabetes mellitus or other metabolic factor are at risk of renal injury. Chronic kidney disease is usually linked to insulin resistance, dyslipidemia, hypertension, and hyperuricemia. Several of the same pathophysiological mechanisms have been found in diabetes mellitus, metabolic syndrome, and chronic kidney disease persons.
Diabetics with circulatory complications are more likely to have hypertension and elevated low-density lipoprotein cholesterol and triglyceride levels. High blood glucose levels may affect platelet function leading to an increase in clot formation which increases the risk for strokes, heart attacks, and poor circulation to the legs and feet. Maintaining control of blood glucose levels and blood pressure levels is vital in preventing these deadly complications. Avoiding smoking and maintaining a normal weight are also very significant in the prevention and/or delay of serious complications resulting from diabetes mellitus.
Chronic hyperglycemia, over time, causes serious complications and may involve circulatory system, eyes, kidneys, and nerves. Normally it is the larger blood vessels in the body (macrovascular complications), circulatory system, or the tiny blood vessels (microvascular complications), generally found in the eyes or kidneys.
Microvascular complications occur in the eyes causing the small blood vessels to become diseased and can lead to retinopathy. This is a slow, painless but progressive complication that if not diagnosed and treated early most likely will cause blindness. Another microvascular complication affects kidney function. When the small blood vessels in the kidneys are damaged, it is referred to as nephropathy. Once nephropathy occurs, the decline of renal function begins decreasing urine output and accumulating toxic waste in the body. Chronic kidney disease is high in mortality and morbidity and is considered to be of pandemic proportions worldwide. Diabetes has been found to be the leading cause of end-stage renal disease (Williams, 2003). After the majority of function of the kidneys has been lost, diabetics may have to have their blood cleansed artificially by means of hemodialysis or peritoneal dialysis. Education needs to be strongly reinforced to delay or prevent kidney disease.
Studies and Results
A study called ‘Metabolic factors and micro-inflammatory state promote kidney injury in type 2 diabetes mellitus patients’ (Cao, 2009) analyzed the association between metabolic syndrome and chronic kidney disease. Chronic kidney disease is usually linked with insulin resistance, hyperuricemia, dyslipidema, and hypertension. These were the metabolic factors used in the study. It was found that the more metabolic factors that existed, the higher the risk of chronic kidney disease. Microinflammatory markers were discovered to play an important role with the accumulation of metabolic syndrome.
Another study, ‘The high prevalence of unrecognized anemia in patients with diabetes and chronic kidney disease: a population based study’ (New, 2008), was aimed to estimate the prevalence of anemia in persons with diabetes and chronic kidney disease. The Hope Hospital in Salford, England used their biochemistry laboratory for this study. The reason for this study was to recommend diabetic persons be screened for anemia to possibly improve their quality of life and may even decrease the progression of chronic kidney disease. Anemia that is not monitored enough in diabetics with low glomerular filtration rates can contribute to morbidity, via exercise intolerance, lethargy, erectile dysfunction, angina, cardiac failure, and claudication. Stage 3 kidney disease diagnosed diabetic persons had the largest number of persons found to have anemia when their hemoglobin levels were studied. It was found that when estimated glomerular filtration rate decreased, so did the hemoglobin level but increased kidney disease progression. A consistency was found that a diagnosis of anemia was not a factor in diabetes until estimated glomerular filtration rate became significantly impaired.
A group of physicians at a teaching hospital in Nigeria performed this study to determine a way to slow the progression of end stage renal disease. The study, ‘Chronic Kidney Disease Screening and Renoprotection in Type 2 Diabetes’ (Agaba, 2008), included examining urine for proteinuria and hematuria, as well as the estimation of glomerular filtration rate by the Cock-Gault formula. Also, examined the modification of diet in a renal disease study and screened the serum creatinine levels. Uncontrolled hypertension in diabetic persons also contributes to chronic kidney disease by means of renoprotection. Most diabetic persons are not screened for hypertension or chronic kidney disease and/or followed on a routine basis.
The study ‘Slowing chronic kidney disease progression: results of prospective clinical trials in adults’ (Nguyen, 2008) was aimed to estimate the prevalence of anemia in persons with diabetes and chronic kidney disease by stage. The Hope Hospital in Salford, England used their biochemistry laboratory for this study. Known diabetic persons who were not on dialysis or erythropoetic stimulating agents was the group selected for this study. The reason for this study was to recommend diabetic persons be screened for anemia to possibly improve their quality of life and may even decrease the progression of chronic kidney disease. Anemia that is not monitored enough in diabetics with low glomerular filtration rates can contribute to morbidity, via exercise intolerance, lethargy, erectile dysfunction, angina, cardiac failure and claudication. Stage 3 kidney disease diagnosed diabetic persons had the largest number of persons found to have anemia when their hemoglobin levels were studied. It was found that when estimated glomerular filtration rate decreased, so did the hemoglobin level but increased kidney disease progression. A consistency was found that a diagnosis of anemia was not a factor in diabetes until estimated glomerular filtration rate became significantly impaired.
In 1999, a new method to estimate creatinine clearance was known as the Modification of Diet in Renal Disease (MDRD) study. With these advancements in renal function estimate guidelines being published, five stages of chronic renal failure have been based solely on the level of glomerular filtration rate. With these guidelines, it created uniformity and appropriately guides the clinical decisions.
Through the multiple studies completed, persons with diabetes and nephropathy or at high risk for nephropathy indicated the use of angiotensin-converting enzyme inhibition or an angiotensin-receptor blocker with or without additional anti-hypertensive medications is associated with reducing the progression of kidney disease. The studies also led to the FDA recommendations to include the use of these medications in treating proteinuria hypertensive diabetics with decreased glomerular filtration rate.
Healthy People 2020 conclude that diabetes mellitus and chronic kidney disease affects more than 20 million people in the United States alone. Diabetes is considered the leading cause of chronic kidney disease and once nephropathy begins, renal function declines causing chaos throughout the human body. Chronic kidney disease is high in mortality and morbidity and is considered to be of pandemic proportions worldwide.
In summary, education and compliance are the keys to that full and productive live that is possible for a person diagnosed with diabetes mellitus. Modifiable risk factors such as weight control, diet, blood pressure, blood glucose levels, and not smoking are very significant in the prevention and/or delay of serious complications resulting from diabetes mellitus. Open communication with your physician is important. Ask about preventable complications and get information on how to control the modifiable risk factors.
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