What is Chronic Kidney Disease?

Chronic Kidney Disease (CKD) is an alteration in the normal function of the kidneys caused by a chronic process and it is usually not reversible. Functionally, the kidney tissue is less capable of performing its functions which include: the filtration of blood, the control of the acid base status, electrolyte concentration control, fluid and blood pressure management, generation of erythropoietin for red blood cell production and  activation of vitamin D.

The processes that most commonly result in CKD are persistent uncontrolled hyperglycemia from diabetes mellitus, persistently elevated blood pressures, acute or subacute inflammatory conditions of the kidneys and genetically mediated anatomic abnormalities such as polycystic kidney disease (PKD). These processes result in scarring and fibrosis of the kidney tissue, with loss of renal cells in the cortex and medullary portions of the kidneys. 

Chronic kidney disease is usually classified in stages, going from I to V. The function that has been chosen to  assign the stages is the filtration function, measured as a variable called glomerular filtration rate (GFR). Although the kidney has many different functions, they are related to each other. The relationship is not perfect, but is is safe to say that if there is a reduction on the filtration function function of the kidneys, the other functions will be affected, in variable degrees. It is also possible that certain functions of the kidney may be affected with little change in other functions, for example, there are conditions that involve abnormalities in the handling of potassium or acidity without a change in the filtration function or generation of erythropoietin, however, these conditions are not too common.

The final stage of CKD is called end-stage renal disease (ESRD). At this stage, renal replacement therapy (RRT) becomes necessary. RRT includes dialysis (in its different modalities) and renal transplantation.

Marco A. Ramos MD

Stroke: People at Risk and its Consequences

"Stroke" is a the common term for an "acute cerebral infarction", which means injury with loss of neurons of the brain tissue. There are 2 main causes for stroke: the obstruction of one of the arteries that feeds blood to the brain and bleeding from blood vessels in the brain. Both situations are very serious and can lead to loss of brain cells, loss of physical or intellectual function and death.

The people who are at risk for stroke are diabetics, people with high blood pressure, smokers, obese and patients with high cholesterol. If someone already has had a stroke he or she has a higher risk to have another one. In addition, for an individual who has coronary artery disease or peripheral artery disease, there is an increased risk of stroke. Atrial fibrillation (AF; an irregular heart beat) increases the chances of stroke, that is the reason why many persons with AF have to take an anticoagulant (blood thinner). Finally, there are genetic conditions that can increase the risk of stroke. Examples of this are sickle cell disease and increased coagulation disorders such as Factor V Leyden.

Stroke can be a devastating condition for the individual and it is definitely a major public health problem¹ due to the immense cost it represents. It accounts for approximately 320 billion dollars every year in healthcare direct and indirect expenditures². The patient has to deal with loss of function, which could be physical  (paralysis of arms, legs and/or face), and intellectual deficits like the loss memory and inability to speak. The recovery from stroke is usually slow and involves the use different levels of rehabilitation services.

References

1. Hankey GJ. StrokeHow Large a Public Health Problem, and How Can the Neurologist Help?. Arch Neurol. 1999;56(6):748-754. 

2. Mozaffarian D, Benjamin EJ, Go AS, et al. Heart Disease and Stroke Statistics-2016 Update: A Report From the American Heart Association. Circulation. 2016;133:e38-e360.

Marco A. Ramos MD

Who is Obese? 5 Dangers of Obesity

The healthcare community has defined obesity as a body mass index (BMI) of 30 or more. The BMI is the ratio between the weight of a person (in kilograms) and the square of the height (in meters). There are many calculators online that can calculate the BMI using pounds and feet/inches. This is a very inexact way of classifying overweight people because there could be very muscular people that could be obese according to this definition. In addition, it may cause shorter people to be overrepresented in the obese population.  In spite of this, the BMI provides an easy way of classifying people according to weight that can lead to meaningful research and can serve as an effective screening tool.

There are many dangers that originate from being obese. I will list here the five most relevant ones

1. Diabetes mellitus. Having excessive adipose tissue causes insulin resistance and some obese people may become diabetic because of this.

2. Hypertension. Obesity is associated with hormonal variations that may lead to salt and water retention and constriction of small arteries. These changes can elevate the blood pressure.

3. Sleep apnea.  This condition is related to obesity. It causes the breathing to stop many times during the night causing problems with oxygenation and getting rid of carbon dioxide.

4. Osteoarthrosis. The extra weight that the obese person has to carry has an impact on the hip and knee joints. This may lead to incapacitating pain and joint replacement surgeries.

5. Cancer. Breast, colon, gallbladder and endometrial malignancies are more common in overweight individuals than in people with normal weight

Diabetes and hypertension are  significant risk factors for coronary artery disease and stroke. Sleep apnea is directly related to hypertension. This means that obesity may impair a person’s health in multiple ways.

Marco A. Ramos MD

3 Macrovascular Risks of Uncontrolled Diabetes Mellitus

Uncontrolled diabetes mellitus (either type 1 or type 2) is associated with several complications caused by the chronic damage that excess glucose causes to the tissues of the body. The vascular tissue, is particularly sensitive and leads to the damage of organs as we are going to see.

Coronary Artery Disease (CAD). Diabetics have a higher rate of heart attacks than the general population. Excess glucose over many years contribute to the generation of atherosclerosis and the formation of plaques in the coronary arteries that will eventually be the cause of the heart attacks. Heart attacks, are also the main cause for heart failure and sudden death.

Cerebrovascular Disease (CVD). A similar problem in the vascular system of the brain is responsible for the appearance of more strokes in diabetics than in the general public. In this case, the atherosclerosis and the plaques are formed in the carotid arteries and the arteries of the brain. Debilitating strokes, and dementia are the main consequences.

Peripheral Artery Disease (PAD). If the atherosclerosis and plaque formation happens in the arteries of the lower extremities, the consequence may be the amputation of different parts of the leg. These can range from losing toes to the loss of an entire limb. It is well known that diabetics have a higher incidence of amputations than non-diabetics

Strict control of the blood sugar is the mainstay of the prevention of these complications. To get to the point of a heart attack, a stroke or an amputation, decades of elevated blood sugar have to be present. In addition, other factors such as smoking, high blood pressure, or genetic predisposition can speed up the process of atherosclerosis. There are many options to control the blood sugar, including many pharmacologic measures such as oral medications and injectables such as insulin and non-pharmacological measures such as diet and exercise.

Marco A. Ramos MD