World Kidney Day: Get to Know your Kidneys!

Article Written by Germaine Guzman

March 12 marks World Kidney Day. The National Kidney Foundation urges Americans to learn more and take steps to preserve kidney health. World Kidney Day will help raise awareness and appreciation for the vital functions the kidney performs.⁴
According to the November 10, 2008 annual report by the U.S Renal Data System (USRDS), rates of Chronic Kidney Disease (CKD) have increased by more than 20% over the last decade.⁴ Data from the National Health & Nutrition Examination Surveys (NHANES), produced by the U.S Centers for Disease Control & Prevention, also indicates an increase in the prevalence of CKD from 12% in 1988 – 1994 to 15% in 2003 – 2006. Among those aged 60 and over, the prevalence increased from 32% to 38% during the same time period.⁴

What do our Kidneys do?

We have two kidneys, each about the size of a fist located on either side of the spine at the base of the rib cage. Each kidney contains tiny units called nephrons which are made up of a very small filter called Glomerulus which is attached to a tubule.² The kidneys perform their life-sustaining job of filtering and returning to the bloodstream about 200 quarts of fluid every 24 hours. The nephrons filter the blood as it passes through removing fluid and waste products.^{2, 4} Approximately 2 quarts are removed from the body in the form of urine, and about 198 quarts of fluid is returned to the blood. The waste products or urine are excreted from the body. Urine is stored in the bladder for anywhere from 1 to 8 hours.⁴

Why are they so important?

When your kidneys are working properly, excess minerals, waste and toxic products leave the body in the urine.²The kidneys are powerful chemical factories that perform the following functions:

Remove waste products from the body.⁴
Remove drugs from the body.⁴
Balances the body’s fluids and controls body chemistry by regulating the amount of salt, fluid and other chemicals in the body.^{2, 4}
Regulates hormones that regulate blood pressure and red blood cell production.^{2, 4}
Regulates hormones in the body that help to control calcium uptake from the intestine.²
Produces an active form of vitamin D that promotes strong, healthy bones.⁴

What can lead to unhealthy or damaged kidneys?

Some of the causes of Kidney Disease include:

Diabetes - Even if it is well managed, diabetes can lead to kidney damage.^{3, 4}
Hypertension (high blood pressure) - If poorly controlled, high blood pressure can be a leading cause of heart attacks, strokes and CKD. CKD is also known to cause high blood pressure.^{3, 4}
Glomerulonephritis - Swelling or inflammation of the tiny filtering units called nephrons in the kidney.³
Polycystic Kidney Disease - An inherited condition which causes large cysts to form in the kidneys.³
Reflux Nephropathy - A bladder valve problem allowing urine to flow back into the kidneys causing scarring.³
Lupus and other diseases that affect the body’s immune system.⁴
Obstructions caused by problems like kidney stones, tumors, or enlarged prostate gland in men.⁴
Repeated urinary infections.⁴
Medications - Some drugs such as Lithium and Cyclosporin can cause kidney failure. Non-steroidal anti-inflammatory drugs (NSAIDS), taken in normal therapeutic doses, may occasionally lead to acute kidney failure.³

So what exactly is CKD?

Often the development of kidney disease is gradual and kidney function worsens over a number of years. If you lose more than one-third of your kidney function, it is called ‘Chronic Kidney Disease’ or CKD.³

You are more at risk of CKD if you:

Have diabetes.³
Have high blood pressure.³
Are obese.³
Are over 50 years old.³
Have a family history of kidney disease.³
Smoke (men who smoke are 3 times more likely to have reduced kidney function).³

Early detection and treatment can often keep CKD from getting worse. When kidney disease progresses, it may eventually lead to kidney failure which requires dialysis or kidney transplant to maintain a healthy life.⁴

The best method of measuring kidney function is called the ‘Estimated Glomerular Filtration Rate’ (eGFR).² This formula uses the level of Creatinine in your blood to estimate how well your kidneys are filtering waste from your blood. It can indicate if there is any kidney damage. The higher the filtration rate, the better the kidneys are working.² If you have any concerns about your kidneys, speak to your doctor.

Tips for keeping your kidneys healthy

Making healthy lifestyle choices can help keep your kidneys functioning well:

Eat plenty of fruits and vegetables including legumes and low glycemic index grain-based foods like bread and pasta.¹
Ensure meats are lean and include white meat such as chicken and fish each week.¹
Reduce the amount of salty or fatty food you consume.¹
Drink plenty of water instead of other drinks.¹
Maintain a healthy weight.¹
Stay fit - Try to be physically active on most days of the week for at least 30 minutes.¹
Don’t smoke.¹
Limit alcohol.¹
Check your blood pressure regularly.¹

Well now that you are a bit more acquainted with your kidneys, why not look at any lifestyle changes that could be made to help keep them healthy!

References

Deakin University – Better Health Channel, October 2008. Kidney Disease- Prevention [Online]. Available at http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Kidney_disease_prevention?open [Accessed 9th March 2009].
Deakin University – Better Health Channel, March 2009. Kidneys explained [Online]. Available at http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Kidneys_explained?open [Accessed 5th March 2009].
Deakin University – Better Health Channel, November 2008. Kidney Failure [Online]. Available at http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Kidney_failure?open [Accessed 9th March 2009].
National Kidney Foundation, 2009. World Kidney Day [Online]. Available at http://www.kidney.org/news/wkd/ [Accessed 5th March 2009].

Last updated 17 June 2009