Obesity

What is obesity?

The definition of obesity varies depending on what one reads, but in general, it is a chronic condition defined by an excess amount body fat. A certain amount of body fat is necessary for storing energy, heat insulation, shock absorption, and other functions. The normal amount of body fat (expressed as percentage of body fat) is between 25-30% in women and 18-23% in men. Women with over 30% body fat and men with over 25% body fat are considered obese.

What is the health risks associated with obesity?

Obesity is not just a cosmetic consideration; it is a dire health dilemma directly harmful to one’s health. Obesity also increases the risk of developing a number of chronic diseases including:

• Insulin Resistance: Insulin resistance (IR) is the condition whereby the effectiveness of insulin in transporting glucose (sugar) into cells is diminished. Fat cells are more insulin resistant than muscle cells; therefore, one important cause of IR is obesity. The pancreas initially responds to IR by producing more insulin. As long as the pancreas can produce enough insulin to overcome this resistance, blood glucose levels remain normal. This IR state (characterized by normal blood glucose levels and high insulin levels) can last years. Once the pancreas can no longer keep up with producing high levels of insulin, blood glucose levels begin to rise, resulting in type 2 diabetes, thus IR is a pre-diabetes condition.
• Type 2 (adult-onset) diabetes: The risk of type 2 diabetes increases with the degree and duration of obesity. Type 2 diabetes is associated with central obesity; a person with central obesity has excess fat around his/her waist, so that the body is shaped like an apple.
• High blood pressure (hypertension): Hypertension is common among obese adults. A Norwegian study showed that weight gain tended to increase blood pressure in women more significantly than in men. The risk of developing high blood pressure is also higher in obese people who are apple shaped (central obesity) than in people who are pear shaped (fat distribution mainly in hips and thighs).
• High cholesterol (hypercholesterolemia)
• Stroke (cerebrovascular accident or CVA)
• Heart attack: The Nurses Health Study found that the risk of developing coronary artery disease increased 3 to 4 times in women who had a BMI greater than 29. A Finnish study showed that for every one kilogram (2.2 pounds) increase in body weight, the risk of death from coronary artery disease increased by one percent. In patients who have already had a heart attack, obesity is associated with an increased likelihood of a second heart attack.
• Congestive heart failure
• Gallstones
• Gout and gouty arthritis
• Osteoarthritis (degenerative arthritis) of the knees, hips, and the lower back
• Sleep apnea
• Pickwick Ian syndrome (obesity, red face, under ventilation, and drowsiness)

What Causes Obesity?

The balance between calorie intake and energy expenditure determines a person’s weight. If a person eats more calories than he or she burns, the person gains weight (the body will store the excess energy as fat). If a person eats fewer calories than he or she burns, he or she will lose weight. Therefore the most common causes of obesity are overeating and physical inactivity. At present, we know that there are many factors that contribute to obesity, some of which have a genetic component:

• Genetics. A person is more likely to develop obesity if one or both parents are obese. Genetics also affect hormones involved in fat regulation. For example, one genetic cause of obesity is leptin deficiency. Leptin is a hormone produced in fat cells, and also in the placenta. Leptin controls weight by signaling the brain to eat less when body fat stores are too high. If, for some reason the body cannot produce enough leptin, or leptin cannot signal the brain to eat less, this control is lost, and obesity occurs.
• Overeating. Overeating leads to weight gain, especially if the diet is high in fat. Foods high in fat or sugar (e.g., fast food, fried food and sweets,) have high energy density (foods that have a lot of calories in small amount of food). Epidemiology studies have shown that diets high in fat contribute to weight gain.
• A diet high in simple carbohydrates. Carbohydrates increase blood glucose levels, which in turn stimulate insulin release by the pancreas, and insulin promotes the growth of fat tissue and can cause weight gain. Some scientists believe that simple carbohydrates (sugars, fructose, desserts, soft drinks, beer, wine, etc.) contribute to weight gain because they are more rapidly absorbed into the blood stream than complex carbohydrates (pasta, brown rice, grains, vegetables, raw fruits, etc.) and thus cause a more pronounced insulin release after meals than complex carbohydrates.
• Frequency of eating. Scientists have observed that people who eat small meals four or five times daily, have lower cholesterol levels and lower and/or more stable blood sugar levels than people who eat less frequently (two or three) large meals daily. One possible explanation is that small frequent meals produce stable insulin levels, whereas large meals cause large spikes of insulin after meals.
• Slow metabolism. Women have less muscle than men. Muscle burns more calories than other tissue (which includes fat). As a result, women have a slower metabolism than men, and hence, have a tendency to put on more weight than men, and weight loss is more difficult for women.
• Physical inactivity. Sedentary people burn fewer calories than people who are active. The National Health and Examination Survey (NHANES) showed that physical inactivity was strongly correlated with weight gain in both sexes.
• Medications. Medications associated with weight gain include certain antidepressants (medications used in treating depression), anti-convulsants (medications used in controlling seizures such as carbamazepine and valproate), diabetes medications (medications used in lowering blood sugar such as insulin, sulfonylurea and thiazolidinediones), certain hormones such as oral contraceptives and most corticosteroids such as Prednisone. Weight gain may also be seen with some high blood pressure medications and antihistamines.
• Psychological factors. For some people, emotions influence eating habits. Many people eat excessively in response to emotions such as boredom, sadness, stress or anger. While most overweight people have no more psychological disturbances than normal weight people, about 30 percent of the people who seek treatment for serious weight problems have difficulties with binge eating.
• Diseases such as hypothyroidism, insulin resistance, polycystic ovary syndrome and Cushing’s syndrome are also contributors to obesity.

How is body fat measured?

Measuring a person’s body fat percentage can be difficult; therefore, two widely used methods are weight-for-height tables and body mass index (BMI). While both measurements have their limitations, they are reasonable indicators that someone may have a weight problem. The calculations are easy, and no special equipment is required. The BMI uses a mathematical formula that accounts for both a person’s weight and height. The BMI equals a person’s weight in kilograms divided by height in meters squared (BMI=kg/m2).

The table below has already done the math and metric conversions. To use the table, find the appropriate height in the left-hand column. Move across the row to the given weight. The number at the top of the column is the BMI for that height and weight.

Table Courtesy of the National Institutes of Health

Body weight in pounds according to height and body mass index.

Below is a table identifying the risk of associated disease according to BMI and waist size

Table Courtesy of the National Institutes of Health

Rheumatoid Arthritis

What is it?

Rheumatoid Arthritis (RA) is a chronic, progressive and disabling auto-immune disease affecting 0.8% of the UK adult population. It is an incredibly painful condition, can cause severe disability (this varies between individuals and depends on how severe/aggressive your disease is) and ultimately affects a person’s ability to carry out everyday tasks. The disease can progress very rapidly (again the speed of progression varies widely between individuals), causing swelling and damaging cartilage and bone around the joints. Any joint may be affected but it is commonly the hands, feet and wrists. It is a systemic, disease which means that it can affect the whole body and internal organs (although this is not the case for everyone with RA) such as the lungs, heart and eyes.

As with other forms of arthritis, rheumatoid arthritis involves inflammation of the joints. A membrane called the synovium lines each of your movable joints. When you have rheumatoid arthritis, white blood cells — whose usual job is to attack unwanted invaders, such as bacteria and viruses — move from your bloodstream into your synovium. Here, these blood cells appear to play an important role in causing the synovial membrane to become inflamed (synovitis).

This inflammation results in the release of proteins that, over months or years, cause thickening of the synovium. These proteins can also damage cartilage, bone, tendons and ligaments. Gradually, the joint loses its shape and alignment. Eventually, it may be destroyed.

Some researchers suspect that rheumatoid arthritis is triggered by an infection — possibly a virus or bacterium — in people with an inherited susceptibility. Although the disease itself is not inherited, certain genes that create an increased susceptibility are. People who have inherited these genes won’t necessarily develop rheumatoid arthritis. But they may have more of a tendency to do so than others. The severity of their disease may also depend on the genes inherited. Some researchers also believe that hormones may be involved in the development of rheumatoid arthritis.

To summarise the consequences of joint inflammation in the rheumatoid joint, see diagram below:

• The capsule, the outermost layer of the joint, is normal in both rheumatoid arthritis and osteoarthritis;
• The lining layer in the rheumatoid arthritis joint is swollen to many times its normal size;
• There is increased amounts of joint fluid between the bone ends;
• The inflamed synovial membrane eats into the bone and the cartilage. The damage of the bone is seen in the x-ray as an erosion.

Other parts of the body can include: (but these things are not affected in everyone with RA)

• Eyes – dryness, inflammation
• Lungs – fluid, fibrosis, nodules (rare)
• Skin – nodules, ulcers
• Heart – fluid, nodules, ischemic heart disease
• Blood – anaemia, low counts

The signs and symptoms of rheumatoid arthritis may come and go over time. They include:

• Pain and swelling in your joints, especially in the smaller joints of your hands and feet
• Generalized aching or stiffness of the joints and muscles, especially after sleep or after periods of rest
• Loss of motion of the affected joints
• Loss of strength in muscles attached to the affected joints
• Fatigue, which can be severe during a flare-up
• Low-grade fever
• Deformity of your joints over time
• General sense of not feeling well (malaise)

FIBROSIS SPONDYLITIS

What is ankylosing spondylitis?

Ankylosing spondylitis is a form of chronic inflammation of the spine and the sacroiliac joints. The sacroiliac joints are located in the low back where the sacrum (the bone directly above the tailbone) meets the iliac bones (bones on either side of the upper buttocks). Chronic inflammation in these areas causes pain and stiffness in and around the spine. Over time, chronic spinal inflammation (spondylitis) can lead to a complete cementing together (fusion) of the vertebrae, a process referred to as ankylosis. Ankylosis leads to loss of mobility of the spine.

Ankylosing spondylitis is 2-3 times more common in males than in females. In women, joints away from the spine are more frequently affected than in men. Ankylosing spondylitis affects all age groups, including children. The most common age of onset of symptoms is in the second and third decades of life.

What causes ankylosing spondylitis?

The tendency to develop ankylosing spondylitis is believed to be genetically inherited, and the majority (nearly 90%) of patients with ankylosing spondylitis are born with the HLA-B27 gene. The HLA-B27 gene appears only to increase the tendency of developing ankylosing spondylitis.

FIBROMYALGIA

What is fibromyalgia?

Fibromyalgia is a chronic condition causing pain, stiffness, and tenderness of the muscles, tendons, and joints. Fibromyalgia is also characterized by restless sleep, awakening feeling tired, fatigue, anxiety, depression, and disturbances in bowel function. Fibromyalgia was formerly known as fibrositis.

While fibromyalgia is one of the most common diseases affecting the muscles, its cause is currently unknown. The painful tissues involved are not accompanied by tissue inflammation. Therefore, despite potentially disabling body pain, patients with fibromyalgia do not develop body damage or deformity. Fibromyalgia also does not cause damage to internal body organs.

What causes fibromyalgia?

The cause of fibromyalgia is not known. Patients experience pain in response to stimuli that are normally not perceived as painful. Researchers have found elevated levels of a nerve chemical signal, called substance P, and nerve growth factor in the spinal fluid of fibromyalgia patients.

Who does fibromyalgia affect?

Fibromyalgia affects predominantly women (over 80 percent) between the ages of 35 and 55. Rarely, fibromyalgia can also affect men, children, and the elderly. It can occur independently, or can be associated with another disease, such as systemic lupus or rheumatoid arthritis.

OSTEOARTHRITIS

What is osteoarthritis?

Osteoarthritis is a type of arthritis that is caused by the breakdown and eventual loss of the cartilage of one or more joints. Cartilage is a protein substance that serves as a “cushion” between the bones of the joints. Osteoarthritis is also known as degenerative arthritis. Among the over 100 different types of arthritis conditions, osteoarthritis is the most common. Osteoarthritis occurs more frequently as we age. Before age 45, osteoarthritis occurs more frequently in males. After age 55 years, it occurs more frequently in females.

Osteoarthritis commonly affects the hands, feet, spine, and large weight-bearing joints, such as the hips and knees. Most cases of osteoarthritis have no known cause and are referred to as primary osteoarthritis. When the cause of the osteoarthritis is known, the condition is referred to as secondary osteoarthritis.

What causes osteoarthritis?

Primary osteoarthritis is mostly related to aging. With aging, the water content of the cartilage increases and the protein makeup of cartilage degenerates. Repetitive use of the joints over the years irritates and inflames the cartilage, causing joint pain and swelling. Eventually, cartilage begins to degenerate by flaking or forming tiny crevasses. In advanced cases, there is a total loss of the cartilage cushion between the bones of the joints. Loss of cartilage cushion causes friction between the bones, leading to pain and limitation of joint mobility. Inflammation of the cartilage can also stimulate new bone outgrowths (spurs) to form around the joints. Osteoarthritis occasionally can be found in multiple members of the same family, implying an heredity (genetic) basis for this condition.

Secondary osteoarthritis is caused by another disease or condition. Conditions that can lead to secondary osteoarthritis include obesity, repeated trauma or surgery to the joint structures, abnormal joints at birth (congenital abnormalities), gout, diabetes and other hormone disorders.

Hormone disturbances, such as diabetes and growth hormone disorders, are also associated with early cartilage wear and secondary osteoarthritis.

What are symptoms of osteoarthritis?

Osteoarthritis is a disease of the joints. Unlike many other forms of arthritis that are systemic illnesses, such as rheumatoid arthritis and systemic lupus, osteoarthritis does not affect other organs of the body. The most common symptom of osteoarthritis is pain in the affected joint(s) after repetitive use. Joint pain is usually worse later in the day. There can be swelling, warmth, and creaking of the affected joints. Pain and stiffness of the joints can also occur after long periods of inactivity, for example, sitting in a theater. In severe osteoarthritis, complete loss of cartilage cushion causes friction between bones, causing pain at rest or pain with limited motion.

Osteoarthritis of the spine causes pain in the neck or low back. Bony spurs that form along the arthritic spine can irritate spinal nerves, causing severe pain, numbness, and tingling of the affected parts of the body.

PSORIATIC ARTHRITIS

What is psoriatic arthritis?

Psoriatic arthritis is a chronic disease characterized by inflammation of the skin (psoriasis) and joints (arthritis). It features patchy, raised, red areas of skin inflammation with scaling. Psoriasis often affects the tips of the elbows and knees, the scalp, the navel, and around the genital areas or anus. Approximately 10% of patients who have psoriasis also develop an associated inflammation of their joints. Patients who have inflammatory arthritis and psoriasis are diagnosed as having psoriatic arthritis.

The onset of psoriatic arthritis generally occurs in the fourth and fifth decades of life. Males and females are affected equally. The skin disease (psoriasis) and the joint disease (arthritis) often appear separately. In fact, the skin disease precedes the arthritis in nearly 80% of patients. The arthritis may precede the psoriasis in up to 15% of patients.

Psoriatic arthritis is a systemic rheumatic disease that can also cause inflammation in body tissues away from the joints other than the skin, such as in the eyes, heart, lungs, and kidneys. Psoriatic arthritis shares many features with several other arthritic conditions, such as ankylosising spondylitis, reactive arthritis (formerly Reiter’s syndrome), and arthritis associated with Crohn’s disease and ulcerative colitis. All of these conditions can cause inflammation in the spine and other joints, and the eyes, skin, mouth, and various organs. In view of their similarities and tendency to cause inflammation of the spine, these conditions are collectively referred to as “spondyloarthropathies.”

What causes psoriatic arthritis?

The cause of psoriatic arthritis is currently unknown. A combination of genetic and immune as well as environmental factors are likely involved. In patients with psoriatic arthritis who have arthritis of the spine, a gene marker named HLA-B27 is frequently, but not always, found.

What symptoms do patients with psoriatic arthritis feel?

In most patients, the psoriasis precedes the arthritis by months to years. The arthritis frequently involve the knees, ankles, and joints in the feet. Usually, only a few joints are inflamed at a time. The inflamed joints become painful, swollen, hot, and red. Sometimes, joint inflammation in the fingers or toes can cause swelling of the entire digit, giving them the appearance of a “sausage.” Joint stiffness is common, and is typically worse early in the morning. Less commonly, psoriatic arthritis may involve many joints of the body in a symmetrical fashion, mimicking the pattern seen in rheumatoid arthritis. Psoriatic arthritis can also cause inflammation of the spine (spondylitis) and the sacrum, causing pain and stiffness in the low back, buttocks, neck and upper back.

ASTHMA

What is Asthma?

Asthma is a chronic inflammation of the bronchial tubes (airways) that cause swelling and narrowing (constriction) of the airways. The result is difficulty breathing.

Bronchial tubes that are chronically inflamed may become overly sensitive to allergens (specific triggers) or irritants (non-specific triggers). The airways may become “twitchy” and remain in a state of heightened sensitivity. This is called “Bronchial Hyperreactivity” (BHR). It is likely that there is a spectrum of bronchial hyperreactivity in all individuals. However, it is clear that asthmatics and allergic individuals (without apparent asthma) have a greater degree of bronchial hyperreactivity than non-asthmatic and non-allergic people. In sensitive individuals, the bronchial tubes are more likely to swell and constrict when exposed to triggers such as allergens, tobacco smoke, or exercise. Amongst asthmatics, some may have mild BHR and no symptoms while others may have severe BHR and chronic symptoms

Normal bronchial tubes

Before we can appreciate how asthma affects the bronchial airways, we should first take a quick look at the structure and function of normal bronchial tubes.

The air we breathe in through our nose and mouth passes through the vocal cords (larynx) and into the windpipe (trachea). The air then enters the lungs by way of two large air passages (bronchi), one for each lung. The bronchi divide within each lung into smaller and smaller air tubes (bronchioles), just like branches of an inverted tree. Inhaled air is brought through these airways to the millions of tiny air sacs (alveoli) that are contained in the lungs. Oxygen (O2) passes from the air sacs into the blood stream through numerous tiny blood vessels called capillaries. Similarly, the body’s waste product, carbon dioxide (CO2), is returned to the air sacs and then eliminated upon each exhalation.

Normal bronchial tubes allow rapid passage of air in and out of the lungs to ensure that the levels of O2 and CO2 remain constant in the blood stream. The outer walls of the bronchial tubes are surrounded by smooth muscles that contract and relax automatically with each breath. This allows the required amount of air to enter and exit the lungs to achieve this normal exchange of O2 and CO2. The contraction and relaxation of the bronchial smooth muscles are controlled by two different nervous systems that work in harmony to keep the airways open.

The inner lining of the bronchial tubes, called the bronchial mucosa, contains: (1) mucus glands that produce just enough mucus to properly lubricate the airways; and (2) a variety of so called inflammatory cells, such as eosinophils, lymphocytes, and mast cells. These cells are designed to protect the bronchial mucosa from the inhaled microorganisms, allergens, and irritants we inhale, and which can cause the bronchial tissue to swell. Remember, however, that these inflammatory cells are also important players in the allergic reaction. Therefore, the presence of these cells in the bronchial tubes causes them to be a prime target for allergic inflammation.

How does asthma affect breathing?

Asthma causes a narrowing of the breathing airways, which interferes with the normal movement of air in and out of the lungs. Asthma involves only the bronchial tubes and does not affect the air sacs or the lung tissue. The narrowing that occurs in asthma is caused by three major factors; inflammation, bronchospasm, and hyper-reactivity.

• Inflammation: The first and most important factor causing narrowing of the bronchial tubes is inflammation. The bronchial tubes become red, irritated, and swollen. The inflammation occurs in response to an allergen or irritant and results from the action of chemical mediators (histamine, leukotrienes, and others). The inflamed tissues produce an excess amount of “sticky” mucus into the tubes. The mucus can clump together and form “plugs” that can clog the smaller airways. Eosinophils and other cells, which accumulate at the site, cause tissue damage. These damaged cells are shed into the airways, thereby contributing to the narrowing.
• Bronchospasm: The muscles around the bronchial tubes tighten during an attack of asthma. This muscle constriction of the airways is called bronchospasm. Bronchospasm causes the airway to narrow further. Chemical mediators and nerves in the bronchial tubes cause the muscles to constrict.
• Hyper-reactivity (Hypersensitivity): In patients with asthma, the chronically inflamed and constricted airways become highly sensitive, or reactive, to triggers such as allergens, irritants, and infections. Exposure to these triggers may result in progressively more inflammation and narrowing

The combination of these three factors results in difficulty with breathing out, or exhaling. As a result, the air needs to be forcefully exhaled to overcome the narrowing, thereby causing the typical “wheezing” sound. People with asthma also frequently “cough” in an attempt to expel the thick mucus plugs. Reducing the flow of air may result in less oxygen passing into the blood stream and if very severe, carbon dioxide may dangerously accumulate in the blood.

Asthma triggers

Asthma symptoms may be activated or aggravated by many agents. Not all asthmatics react to the same triggers. Additionally, the effect that each trigger has on the lungs varies from one individual to another. In general, the severity of your asthma depends on how many agents activate your symptoms and how sensitive your lungs are to them. Most of these triggers can also worsen nasal or eye symptoms.
Triggers fall into two categories:

• Allergens (“specific”)
• Non-allergens – mostly irritants (non-“specific”)

Once your bronchial tubes (nose and eyes) become inflamed from an allergic exposure, a re-exposure to the offending allergens will often activate symptoms. These “reactive” bronchial tubes might also respond to other triggers, such as exercise, infections, and other irritants. The following is a simple checklist.

Common Asthma Triggers:

Allergens

• “Seasonal” pollens.
• Year-round dust mites, molds, pets, and insect parts.
• Foods, such as fish, egg, peanuts, nuts, cow’s milk, and soy
• Additives, such as sulfites.
• Work-related agents, such as latex.

Irritants

• Respiratory infections, such as those caused by viral “colds,” bronchitis, and sinusitis.
• Drugs, such as aspirin, other NSAIDs (nonsteroidal anti-inflammatory drugs), and Beta Blockers (used to treat blood pressure and other heart conditions).
• Tobacco smoke.
• Outdoor factors, such as smog, weather changes, and diesel fumes.
• Indoor factors, such as paint, detergents, deodorants, chemicals, and perfumes.
• Nighttime
• GERD (gastro-esophageal reflux disorder)
• Exercise, especially under cold dry conditions
• Work-related factors, such as chemicals, dusts, gases, and metals
• Emotional factors, such as laughing, crying, yelling, and distress
• Hormonal factors, such as in premenstrual syndrome

Typical symptoms of asthma

The symptoms of asthma vary from person to person and in any individual from time to time. It is important to remember that many of these symptoms can be subtle and similar to those seen in other conditions. All of the symptoms mentioned below can be present in other respiratory, and sometimes, in heart conditions. This potential confusion makes identifying the settings in which the symptoms occur and diagnostic testing very important in recognizing this disorder.

The 4 Major Recognized Symptoms:

• Shortness of breath – especially with exertion or at night
• Wheezing – a whistling or hissing sound when breathing out
• Coughing – may be chronic; usually worse at night and early morning. May occur after exercise or when exposed to cold, dry air
• Chest tightness – may occur with or without the above symptoms

HIGH BLOOD PRESSURE

What is high blood pressure?

High blood pressure or hypertension means high pressure (tension) in the arteries. The arteries are the vessels that carry blood from the pumping heart to all of the tissues and organs of the body. High blood pressure does not mean excessive emotional tension, although emotional tension and stress can temporarily increase the blood pressure. Normal blood pressure is below 120/80; blood pressure between 120/80 and 139/89 is called “pre-hypertension”, and a blood pressure of 140/90 or above is considered high blood pressure. The systolic blood pressure, which is the top number, represents the pressure in the arteries as the heart contracts and pumps blood into the arteries. The diastolic pressure, which is the bottom number, represents the pressure in the arteries as the heart relaxes after the contraction. The diastolic pressure, therefore, reflects the minimum pressure to which the arteries are exposed.

An elevation of the systolic and/or diastolic blood pressure increases the risk of developing heart (cardiac) disease, kidney (renal) disease, hardening of the arteries (atherosclerosis or arteriosclerosis), eye damage, and stroke (brain damage). These complications of hypertension are often referred to as end-organ damage because damage to these organs is the end result of chronic (long duration) high blood pressure. Accordingly, the diagnosis of high blood pressure in an individual is important so that efforts can be made to normalize the blood pressure and, thereby, prevent the complications. Since hypertension affects approximately 1 in 4 adults in the United States, it is clearly a major public health problem.

Whereas it was previously thought that diastolic blood pressure elevations were a more important risk factor than systolic elevations, it is now known that for individuals older than 50 years of age systolic hypertension represents a greater risk.

What causes high blood pressure?

Two forms of high blood pressure have been described–essential (or primary) hypertension and secondary hypertension. Essential hypertension is a far more common condition and accounts for 95% of hypertension. The cause of essential hypertension is multifactorial, that is, there are several factors whose combined effects produce hypertension. In secondary hypertension, which accounts for 5% of hypertension, the high blood pressure is secondary to (caused by) a specific abnormality in one of the organs or systems of the body.

Essential hypertension develops only in groups or societies that have a fairly high intake of salt, exceeding 5.8 grams daily. In fact, salt intake may be a particularly important factor in relation to essential hypertension in several situations. Thus, excess salt may be involved in the hypertension that is associated with advancing age. Genetic factors are thought to play a prominent role in the development of essential hypertension. However, the genes for hypertension have not yet been identified.

What are the causes of secondary high blood pressure?

As mentioned previously, 5% of people with hypertension have what is called secondary hypertension. This means that the hypertension in these individuals is secondary to (caused by) a specific disorder of a particular organ or blood vessel, such as the kidney, adrenal gland, or aortic artery.

• Renal (kidney) hypertension: Diseases of the kidneys can cause secondary hypertension. This type of secondary hypertension is called renal hypertension because it is caused by a problem in the kidneys. One important cause of renal hypertension is narrowing (stenos is) of the artery that supplies blood to the kidneys (renal artery).
• Adrenal gland tumors: Two rare types of tumors of the adrenal glands are less common, secondary causes of hypertension. (The adrenal glands sit right on top of the kidneys.) Both of these tumors produce excessive amounts of hormones (adrenal hormones) that cause high blood pressure. These tumors can be diagnosed from blood tests, urine tests, and imaging studies of the adrenal glands.
• Coarctation of the aorta: Coarctation of the aorta is a rare hereditary disorder that is one of the most common causes of hypertension in children. This condition is characterized by a narrowing of a segment of the aorta, the main large artery coming from the heart. The aorta delivers blood to the arteries that supply all of the body’s organs, including the kidneys. The narrowed segment (coarctation) of the aorta generally occurs above the renal arteries, which causes a reduced blood flow to the kidneys. This lack of blood to the kidneys prompts the renin-angiotensin-aldosterone hormonal system to elevate the blood pressure.

High blood pressure is called “the silent killer” because it usually causes no symptoms for many years, even decades, until it finally damages certain critical organs. Poorly controlled hypertension ultimately can cause damage to blood vessels in the eye, thickening of the heart muscle and heart attacks, hardening of the arteries (arteriosclerosis), kidney failure, and strokes.

High salt intake, obesity, lack of regular exercise, excessive alcohol or coffee intake, and smoking may all adversely affect the outlook for the health of an individual with hypertension. Screening, diagnosing, treating, and controlling hypertension early in its course can significantly reduce the risk of developing strokes, heart attacks, or kidney failure. Lifestyle adjustments in diet and exercise and compliance with medication regimes are important factors in determining the outcome for people with hypertension

Diabetes

What is diabetes?

Diabetes mellitus is a group of metabolic diseases characterized by high blood sugar (glucose) levels, which result from defects in insulin secretion, or action, or both. Diabetes mellitus, commonly referred to as diabetes (as it will be in this article) was first identified as a disease associated with “sweet urine,” and excessive muscle loss in the ancient world. Elevated levels of blood glucose (hyperglycemia) lead to spillage of glucose into the urine, hence the term sweet urine. Normally, blood glucose levels are tightly controlled by insulin, a hormone produced by the pancreas. Insulin lowers the blood glucose level. When the blood glucose elevates (for example, after eating food), insulin is released from the pancreas to normalize the glucose level. In patients with diabetes, the absence or insufficient production of insulin causes hyperglycemia. Diabetes is a chronic medical condition, meaning that although it can be controlled, it lasts a lifetime.

What causes diabetes?

Insufficient production of insulin (either absolutely or relative to the body’s needs), production of defective insulin (which is uncommon), or the inability of cells to use insulin properly and efficiently leads to hyperglycemia and diabetes. This latter condition affects mostly the cells of muscle and fat tissues, and results in a condition known as “insulin resistance.” This is the primary problem in type 2 diabetes. The absolute lack of insulin, usually secondary to a destructive process affecting the insulin producing beta cells in the pancreas, is the main disorder in type 1 diabetes. In type 2 diabetes, there also is a steady decline of beta cells that adds to the process of elevated blood sugars. Essentially, if someone is resistant to insulin, the body can, to some degree, increase production of insulin and overcome the level of resistance. After time, if production decreases and insulin cannot be released as vigorously, hyperglycemia develops.

Insulin is a hormone that is produced by specialized cells (beta cells) of the pancreas. (The pancreas is a deep-seated organ in the abdomen located behind the stomach.) In addition to helping glucose enter the cells, insulin is also important in tightly regulating the level of glucose in the blood. After a meal, the blood glucose level rises. In response to the increased glucose level, the pancreas normally releases more insulin into the bloodstream to help glucose enter the cells and lower blood glucose levels after a meal. When the blood glucose levels are lowered, the insulin release from the pancreas is turned down. It is important to note that even in the fasting state there is a low steady release of insulin than fluctuates a bit and helps to maintain a steady blood sugar level during fasting. In normal individuals, such a regulatory system helps to keep blood glucose levels in a tightly controlled range. As outlined above, in patients with diabetes, the insulin is either absent, relatively insufficient for the body’s needs, or not used properly by the body. All of these factors cause elevated levels of blood glucose (hyperglycemia).

What are the different types of diabetes?

There are two major types of diabetes, called type 1 and type 2. Type 1 diabetes was also called insulin dependent diabetes mellitus (IDDM), or juvenile onset diabetes mellitus. In type 1 diabetes, the pancreas undergoes an autoimmune attack by the body itself, and is rendered incapable of making insulin. Abnormal antibodies have been found in the majority of patients with type 1 diabetes. Antibodies are proteins in the blood that are part of the body’s immune system. The patient with type 1 diabetes must rely on insulin medication for survival.

Type 2 diabetes was also referred to as non-insulin dependent diabetes mellitus (NIDDM), or adult onset diabetes mellitus (AODM). In type 2 diabetes, patients can still produce insulin, but do so relatively inadequately for their body’s needs, particularly in the face of insulin resistance as discussed above. In many cases this actually means the pancreas produces larger than normal quantities of insulin. A major feature of type 2 diabetes is a lack of sensitivity to insulin by the cells of the body (particularly fat and muscle cells). In addition to the problems with an increase in insulin resistance, the release of insulin by the pancreas may also be defective and suboptimal. In fact, there is a known steady decline in beta cell production of insulin in type 2 diabetes that contributes to worsening glucose control. (This is a major factor for many patients with type 2 diabetes who ultimately require insulin therapy.) Finally, the liver in these patients continues to produce glucose through a process called gluconeogenesis despite elevated glucose levels. The control of gluconeogenesis becomes compromised.

What are diabetes symptoms?

The early symptoms of untreated diabetes are related to elevated blood sugar levels, and loss of glucose in the urine. High amounts of glucose in the urine can cause increased urine output and lead to dehydration. Dehydration causes increased thirst and water consumption. The inability of insulin to perform normally has effects on protein, fat and carbohydrate metabolism. Insulin is an anabolic hormone, that is, one that encourages storage of fat and protein. A relative or absolute insulin deficiency eventually leads to weight loss despite an increase in appetite. Some untreated diabetes patients also complain of fatigue, nausea and vomiting. Patients with diabetes are prone to developing infections of the bladder, skin, and vaginal areas. Fluctuations in blood glucose levels can lead to blurred vision. Extremely elevated glucose levels can lead to lethargy and coma.

What is the impact of diabetes?

Over time, diabetes can lead to blindness, kidney failure, and nerve damage. These types of damage are the result of damage to small vessels, referred to as microvascular disease. Diabetes is also an important factor in accelerating the hardening and narrowing of the arteries (atherosclerosis), leading to strokes, coronary heart disease, and other large blood vessel diseases. This is referred to as macrovascular disease.