Take care of your kidneys

Take care of your kidneys

About seven years ago, hospital laboratories routinely introduced a new blood test for kidney function. Called the eGFR, it measured how efficiently your body's filter, the kidneys, were doing their job. Overnight, great swathes of my practice population were labelled as having 'chronic kidney disease', or CKD and many of them panicked. As we've learned since then, many needed nothing more than a yearly blood and blood pressure test and they could stop worrying.
CKD is defined on the basis of your eGFR reading and whether there's protein in your urine which has leaked out through your kidneys. An eGFR reading of over 60 is normal; 30-59 is stage 3 CKD; 15-29 is stage 4; and under 15 is stage 5.
If your eGFR drops too low (under 15), you need dialysis or a kidney transplant. But this is the exception. Everyone's eGFR drops with age. But a gradual drop is usually fine and even normal, depending on your age - it's a rapid fall-off that doctors worry about. If your blood pressure is well controlled, an eGFR level of 50 or 55 when you're 70 is fine if it stays pretty stable year on year. In fact, your kidneys will probably outlast you!

A. Kidney disease - who's at risk?
The risk factors for chronic kidney disease are, on the whole, the same as for heart attack and stroke. Diabetes and high blood pressure are the most common culprits. However, other conditions affect either just the kidneys - among them glomerulonephritis and adult polycystic kidney disease - and conditions such as lupus and Henoch-Schönlein purpura can also damage the kidneys.

B. Kidney disease - what can I do about it?
If you have CKD, your kidneys are more at risk if you get dehydrated. Do keep up your fluid intake in the summer (unless you've been advised not to). And do speak to your doctor if you get a tummy bug, which increases your risk of dehydration.
If you don't have diabetes, (type 1 or type 2) the key to protecting your kidneys is to keep your blood pressure controlled. If you're under 75 or so, your doctor may want to get your blood pressure down below 140/90 or even 130/80. Blood pressure control is also paramount for people with diabetes, but tight blood sugar control also plays a major part in protecting your kidneys.
Two groups of blood pressure-lowering medicines called the ACE inhibitors (they all have names ending in '-pril' and the ARBs (all with names ending in '-sartan') offer extra protection to your kidneys.

C. Drug alert!
Some medicines can damage your kidneys. Others are filtered out of the body by your kidneys. This means if you have CKD, the levels might build up to dangerous levels. Your doctor will keep an eye on your tablets and may drop the dose or change some tablets if your kidney function drops.
Most people don't come to harm with anti-inflammatory drugs like naproxen and ibuprofen, but in some people they're toxic to the kidneys. If you've been taking anti-inflammatory drugs for some time and your doctor suggests you should stop them, this may be why.

D. Diabetes and your kidneys
If you have type 1 or type 2 diabetes your medical team should check your urine for glucose and a blood test for your kidney function at least once a year. That's because high blood sugar can damage your kidneys. And that's one reason it's important to take your medication and get regular diabetes check-ups. Other complications of diabetes related to high blood sugar include eyesight problems and nerve damage, which can cause pain in the legs or foot ulcers. Paying attention to your diet and taking your blood sugar-lowering medication will protect against these, too.

E. What happens if my kidneys fail?
Without treatment, you couldn't live if your kidneys weren't filtering harmful waste and excess water from your body. So thank goodness for treatment! More than 40,000 people in the UK live with kidney failure. Some have had a kidney transplant, but more than half have regular dialysis. There are two main kinds of dialysis - in the most common kind, haemodialysis, you spend about three four-hour sessions a week 'hooked up' to a machine that filters all the toxins from your body. Many people live for years on this regular treatment. Having a kidney replacement removes the need for dialysis but involves taking regular medicines to stop your body rejecting your kidney.