Kidney

http://healthletter.mayoclinic.com/content/pdf.cfm?p=228/201012.PDF&d=ART1

Ways to save your kidneys

What you can do

When it comes to your kidneys, what you don't know may — in the long run — end up hurting you.
Healthy kidneys are amazing organs that filter waste and excess fluid from your blood. But, if you're living with unrecognized chronic kidney disease, you may have no inkling that anything's wrong until your kidney function is significantly impaired. Kidney failure that's detected early often can be significantly slowed or even halted by identifying and treating the underlying condition and making lifestyle changes.
A critical piece in detecting kidney trouble is being aware of factors that may put you at greater risk of kidney disease. Generally, with your doctor's help, it's possible to identify measures you can take that may help save your kidneys.
Faltering filters
Normally, about 50 gallons of blood are pumped through your kidneys on a daily basis. Each kidney has about 1 million filtering units, called glomeruli (glo-MER-u-li), which are each connected with a tubule to form nephrons. When all is well, some of the functions that your nephrons perform include:

• Removal of sodium and water to maintain fluid balance in your body
  
• Elimination of creatinine, a waste product from normal muscle function
  
• Elimination of urea, a waste product of protein breakdown
  
• Fine-tuning levels of minerals, such as calcium, phosphorus and potassium

Healthy kidneys also regulate the acid-base balance in your blood, release hormones that help regulate blood pressure, stimulate red blood cell production and promote bone health.
However, kidney health isn't a given. Several factors may increase the risk of chronic kidney disease. Some are outside of your control. These include being 65 or older, having a family history of kidney disease, or being black, Native American or Asian-American. But other risk factors may be addressed and very possibly modified with treatment or lifestyle changes. These include:

• Diabetes
  
• High blood pressure (hypertension)
  
• Heart disease
  
• Smoking
  
• Obesity
  
• High cholesterol (hyperlipidemia)

Steps in the right direction
If you're older than 65 or have other risk factors for kidney disease, talk with your doctor about getting your kidney function checked. Simple testing — usually including blood pressure measurement and blood and urine tests — can indicate how well your kidneys are doing their job and whether there may be an underlying problem that needs to be addressed or explored further.
Steps you can take to help save your kidneys might include:

• Carefully monitoring and managing diabetes — The presence of diabetes is of particular interest because diabetes is the most common cause of chronic kidney disease. Uncontrolled high blood sugar levels due to diabetes damages many organs, including the kidneys (diabetic nephropathy), heart and blood vessels. It's critically important to monitor and control blood sugar (glucose) levels. Careful monitoring provides valuable information about how exercise, food, medications, stress and many other factors affect your blood sugar. Work with your doctor to fine-tune medications or insulin as needed and to identify other tools that can help you reach your goals.
  
• Making every effort to control hypertension — When it comes to kidney health, the closer your blood pressure is to its target range, the better off your kidneys are. Hypertension damages the kidneys' small blood vessels, so the kidneys don't work as effectively. Hypertension can itself be a cause of chronic kidney disease, and it can also be caused by chronic kidney disease.

Lifestyle choices — such as eating a heart-healthy diet, including physical activity in your daily routine and losing excess weight — can play roles in helping reduce or control hypertension or in getting blood pressure readings down if they're approaching the hypertension threshold.
Work with your doctor to create an action plan and decide what, if any, medications may help you reach your goals.
Two classes of drugs may be especially helpful in lowering blood pressure and preserving your kidney function when hypertension, diabetes or both are present. They are angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs).
ACE inhibitors and ARBs reduce the protein that leaks from kidneys that are under stress and — in some people — may slow the rate of chronic kidney disease. Proper monitoring by your health care provider is important.
Additional kidney-preserving steps may include:

• Avoiding use of large amounts of pain relievers — Kidney damage may be caused by long-term use of various pain relievers in large amounts. These include aspirin, acetaminophen (Tylenol, others), and nonsteroidal anti-inflammatory drugs (NSAIDs), which include among many others, drugs such as ibuprofen (Advil, Motrin, others), naproxen (Aleve, Naprosyn, others) and the COX-2 inhibitor celecoxib (Celebrex).
  
• Eating with kidney health in mind — While it's important to eat enough protein to meet your body's needs, many people consume more protein than is actually needed. Reducing the amount of protein in your diet may be recommended to help slow progression of chronic kidney disease. Your doctor may recommend a low-protein diet and refer you to a dietitian, who can suggest ways to eat less protein while still enjoying a healthy diet.

Another dietary consideration is the amount of salt (sodium) in your diet. To help control hypertension and reduce fluid retention, be mindful of sodium levels in the foods you eat, and especially in convenience foods, which often have added salt.
Examples include frozen dinners, canned soups and many fast foods. Other foods with added salt include canned vegetables, salty snack foods, and processed meats and cheeses.
Another consideration may be limiting potassium in your diet. Under normal circumstances, potassium in the foods you eat plays a role in preventing and controlling hypertension. Foods that contain a higher amount of potassium include oranges, potatoes, bananas, dried fruits and dried beans. As kidneys decline in function, they're less able to eliminate potassium. The resulting abnormally high potassium levels in the blood can cause heart rhythm problems.

• Not smoking — If you smoke or use tobacco products, stop. Smoking makes kidney and heart disease worse.

Testing how your kidneys measure up Getting a read on how well your kidneys are functioning often starts with a few tests that measure aspects of your blood and what's being excreted in your urine.
Typical blood and urine tests include:

• Serum creatinine level in the blood — With normal activity, muscle cells release a waste product called creatinine into the blood for removal by healthy kidneys. But when your kidneys aren't working to their normal capacity, creatinine builds up in your blood. The serum creatinine level can be used to estimate your glomerular filtration rate (GFR), which is widely used to determine the level of kidney function in people with chronic kidney disease.
  
• Blood urea nitrogen (BUN) level in the blood — As your body breaks down protein from foods, it produces urea as a normal waste product that's removed from blood by your kidneys. When kidney function declines, the BUN level is higher than normal.
  
• Albumin or other proteins — Normally, kidneys remove waste products from blood to be excreted in urine while leaving proteins in the blood. A sensitive indicator of kidney decline is the appearance of a very small amount of the blood protein albumin in urine (microalbuminuria). As kidney function deteriorates, albumin levels along with other proteins increase in urine (macroalbuminuria, proteinuria).

If you're at high risk of kidney disease — notably, if you have diabetes or hypertension — the ratio of albumin to creatinine in the urine can help your doctor detect kidney disease.