One of the worst things high blood sugars do to your body is that they slowly destroy your kidneys.

Unfortunately, as is the case with so many "diabetic" complications, this organ destruction also appears to begin long before many people are given a diabetes diagnosis.

The landmark UKPDS study found that one out of eight people diagnosed with diabetes already were leaking small amounts of protein into their urine. This symptom, called "microalbuminuria." is an early sign that kidneys have been damaged.

Though there is no total agreement as to why this occurs, some factors that promote kidney damage are:

1. High blood pressure. When blood pressure is high, large protein molecules, including those that are glycosylated (covered with sticky excess sugar molecules) are pushed through the pores of the kidney's filtration units, damaging them.

2. High blood sugar. When normal glucose regulation fails, the kidneys must remove excess glucose from the blood, leading to high concentrations of glucose in the kidneys. These glucose molecules clog up tiny capillaries in the kidneys as they do those elsewhere in the body.

3. Painkillers. Unfortunately for a generation hooked on "Vitamin I" it turns out that long term use of Ibuprofen, and Tylenol can all damage kidneys severely.

There is some suggestion that the risk goes up as the lifetime dose goes up. taking one thousand pills of Tylenol per lifetime, for example, appears to up your risk of kidney failure significantly, as does taking 5000 NSAID pills.

4.Sodium Phosphate Colon Cleansing Drugs combined with ACE inhibitors or ARBs. This drug, prescribed to cleanse the colon before colonoscopy, can cause acute and permanent kidney failure in people who are taking common blood pressure medicines.

5.Strong Fluctuations in Blood Sugar. An in vitro study (that is, a study done on tissue in the lab, not live people) found that exposing kidney cells to blood sugar levels that fluctuated between 135 mg/dl and 270 mg/dl did more damage to those cell--in terms of causing growth of fibrous tissue--than constant exposure to the high blood sugars. The explanation given involved osmotic changes caused by the fluctuations as well as the suppression of some expression of genes that countered the growth of fibrous tissue when exposed to high blood sugars in a steady state.

Of note in this study, too, are the many graphs showing that a steady exposure to blood sugars of only 135 mg/dl was almost the same as exposure to a steady normal blood sugar level of 90 mg/dl in terms of spurring the growth of fibrous tissue in the kidney. It is fibrous tissue that destoys kidney function.

The authors conclude, "These results support the recommendation for postprandial monitoring of glucose levels in patients with diabetes mellitus and imply that important differences in end organ damage could occur in individuals with similar HbA1c but different postprandial glucose levels." They go on to explain that their findings prove that it is not glycation (the attachment of glucose molecules to proteins), as is usually believed, that destroys the kidney tissue so much as the effect of the fluctuations of blood sugar on gene expression. They urge more attention to eliminating spikes.

6. Coke, Pepsi and other cola drinks with Phosphoric Acid.
A July 2007 study found that two cola drinks a day, whether regular or diet, doubled the risk of kidney damage. The culprit is apparently the phosporic acid (which also leaches calcium out of bones and promotes osteoporosis.) Sodas with citric acid did not worsen kidney disease.

As a person with diabetes you already have enough risk factors to consider, why make things worse with these dangerous cola drinks!

http://epidem.com/pt/re/epidemiology/abstract.00001648-200707000-00017.htm

Carbonated Beverages and Chronic Kidney Disease. Saldana, Tina M.; Basso, Olga; Darden, Rebecca; Sandler, Dale P.. Epidemiology. 18(4):501-506, July 2007.

Does a Low Carb Diet Cause Kidney Damage?

The belief that high protein diets cause kidney damage is one reason why, for many years, doctors warned people with diabetes that low carb diets would kill their kidneys.

Fortunately, this turns out not to be true. While almost any intake of protein is a problem for people with advanced kidney disease, studies have found repeatedly that for people with normal kidney function or early diabetic changes the low carb diet not only doesn't promote kidney damage, it also reduces blood pressure, which is a major cause of kidney damage and may actually reverse early kidney changes.

In fact, people who are able to normalize their blood sugars with a low carb diet often report that their kidney function recovers and that microalbumin disappears from their urine.

One possible reason this may happen is because a low carb diet is really a high fat diet, not a high protein diet. While protein might make up a larger percentage of intake on a low carb diet, the actual amount of protein eaten is usually not all that different from that found in a low fat diet.

Think of it this way. If I eat a hamburger with no bun and no fries and a salad and you eat a hamburger, bun, and fries, my protein intake may be 50% of the calories I ingest, making it look like I'm eating a "high protein" diet. You are eating the same amount of protein, but the intake of all those high calorie carbohydrates makes your protein intake a much smaller percentage of your total calorie intake, so a nutritionist will consider this a safer, "lower protein" intake.

Meanwhile, someone eating a high carb diet has to contend with all the glucose from those carbohydrates that are routed through the kidneys, while the person eating the hamburger and salad will not because their blood sugar will not rise out of a normal range.

If you are really concerned about possible problems with a high protein diet and your kidneys there is a simple solution. Don't EAT a high protein diet. Eat a low carbohydrate diet with just enough protein to provide enough to repair your muscles and organs and provide the glucose
needed to run your brain.

Detailed instructions on how to compute your exact protein need while eating a low carb diet based on an analysis of mainstream nutritional research can be found on my Calculate Your Protein Needs page.

It's worth noting that if you eat only as much protein as you need, you will also eliminate the bad breath that is common among those on low carb diets. It comes from the compounds produced by the breakdown of excess protein. When you eat only the amount of protein you need, your body doesn't produce these compounds as the protein is all used up.

How Can You Tell How Healthy Your Kidneys Are

If you have abnormal blood sugars--caused by diagnosed diabetes or by pre-diabetes--your doctor should run a "microalbumin" test at least every year to watch for signs of early kidney damage.

The microalbumin test is a simple test that requires only that you provide a urine sample when you go to the lab.

Another more accurate test of kidney function is one where you collect an entire day's worth of urine which is then analyzed for protein. Few doctors will order this, but if yours does, congratulate yourself on finding doctor who is aware of what it takes to keep your kidneys healthy.

If your doctor doesn't order at least a microalbumin test for you, it is a good sign you need to find a new and more up to date doctor immediately!

A cheaper test doctors often run gives you your "creatinine clearance rate" and estimated GFR (a measure of how much filtering your kidneys are doing. One problem with this is that when you have high blood sugars, you may for a while have a higher than normal GFR, which will NOT be detected by the simple test and will be considered normal.

Unfortunately, higher than normal GFRs caused by your body dumping lots and lots of glucose eventually give way to lowered GFRs which are a sign that your kidneys are on their way to failing. You don't want to wait for that test result to find out you are in trouble. The microalbumin test gives you an early warning you can put to good use since the damage it shows CAN be reduced or eliminated by normalizing your blood sugars.

What To Do If You Have Early Signs of Kidney Damage?

Normalizing your blood sugars will help reverse early kidney damage.

Normalizing means getting to truly normal--not the damagingly high blood sugar levels that the ADA and most doctors tell you are fine. If you let your A1c stay near 7% and only test your blood sugar when you first wake up, you can pretty much expect to see any kidney damage get much, much worse.

You must get your blood sugar as close as you can to 5%, with post-meal blood sugars always under 140 mg/dl at 2 hours after eating.

You may be able to do this with a lower carb diet alone, but most people with Type 2 diabetes will find that they need a combination of drugs that combat insulin resistance and insulin to achieve this.

Most importantly, you need a doctor who is committed to helping you achieve this. If your doctor is not willing to work with you to get to normal blood sugars when you show signs of early kidney disease you must find a doctor who will. Ideally such a doctor would be an endocrinologist who is a member of the American Association of Clinical Endocrinologists and endorses their recommendations for blood sugar control. But if you are unable to be treated by an endocrinologist a family doctor who keeps up to date, or who will work with you if YOU bring in the research supporting the blood sugars you want to achieve will work.

Control Blood Pressure with an ACE Inhibitor or ARB

These two classes of drugs have been shown to prevent kidney damage in people with diabetes better than diuretics like HCTZ and other classes of blood pressure medications.

There is a generic ACE inhibitor on the market, lisinopril, which is more affordable for people on limited incomes. ARBs, which must be used by people who cannot tolerate ACE inhibitors are more expensive. That class of drugs includes Diovan and Avapro.

Both these classes of drugs appear to lower insulin resistance by a small amount, too.

Whatever it takes, you must keep your blood pressure as normal as possible if you have any signs of diabetic kidney disease.

Don't Drink Coke, Pepsi or any other soda with Phosporic Acid

The manufacturers will undoubtedly argue that one study isn't enough to damn their popular sodas, and that we should await further research. But because people with diabetes already are at risk for kidney disease, we should avoid anything that looks like it might further damage our kidneys, especially nutritionally worthless sodas which have already been implicated in weakening our bones.

Go EASY with Painkillers

Don't take painkillers like Tylenol or Ibuprofen (and other NSAIDS like Motrin, Aleve, and Celebrex) unless you really need them. When you do take them, avoid the "extra strength" sized pills and look for the lowest dose that will control your pain. You want to live a very long time and the troubling "lifetime dose" statistics of these drugs mean that they can be toxic to everyone, not just people with diabetes. Add their toxicity to the problems caused by diabetic blood sugars and you are looking at a formula for kidney loss.

Never use a Sodium Phosphate Drug before Colonoscopy

These drugs rarely can cause complete kidney failure. Why dice with fate. There are other preparations available that don't carry this risk. Make sure to demand one from your doctor if you go for a colonoscopy.

What is "Spilling Sugar" and How Does It Relate to Kidney Damage

Each person has a certain blood sugar level at which the kidneys will start pulling glucose out of the blood stream and eliminating it in the urine. The average level at which this happens is around 180 mg/dl (10 mmol/l). In fact, before blood sugar meters became common, most doctors diagnosed type 2 diabetes using a urine dip, and patients "controlled" their blood sugar by testing their urine for glucose and feeling confident they were doing well if they didn't see any.

However, that 180 mg/dl threshold is only an average. Individuals vary greatly in where they, personally, will spill glucose into the urine.

Some people have forms of diabetes (particularly MODY-3) where they can spill glucose in urine at levels as low as 140 mg/dl.

Others of us, and I'm one of them, have forms of diabetes where glucose doesn't appear in the urine until our blood sugar goes over 250 mg/dl. (That is one reason I had to wait so many years to get a formal diagnosis. For decades my doctors only screened me for diabetes with a urine dip.)

It is possible that there is a relationship between how much glucose appears in the urine and your risk for kidney damage, though there isn't enough research to draw any conclusions. But if your renal threshold is unusually low, it makes sense to try to keep your blood sugar at a level low enough that you don't spill sugar, even if you are spilling at a level your doctor tells you is "nothing to worry about."

REFERENCES

Analgesic Nephropathy - NIH NIDDK


Risk of Kidney Failure Associated with the Use of Acetaminophen, Aspirin, and Nonsteroidal Antiinflammatory Drugs.
Thomas V. Perneger, Paul K. Whelton, and Michael J. Klag

Acute Phosphate Nephropathy following Oral Sodium Phosphate Bowel Purgative: An Underrecognized Cause of Chronic Renal Failure.
Glen S. Markowitz, M. Barry Stokes, Jai Radhakrishnan, Vivette D., D’Agati


A low-carbohydrate diet may prevent end-stage renal failure in type 2 diabetes. A case report.
Jørgen Vesti Nielsen,corresponding author Per Westerlund, and Per Bygren

Nephropahty in Diabetes

Short-term peaks in glucose promote renal fibrogenesis independently of total glucose exposure.T. S. Polhill, S. Saad P. Poronnik,G. R. Fulcher, and C. A. Pollock. Am J Physiol Renal Physiol 287: F268-F273, 2004.
http://ajprenal.physiology.org/cgi/content/full/287/2/F268

http://epidem.com/pt/re/epidemiology/abstract.00001648-200707000-00017.htm

Carbonated Beverages and Chronic Kidney Disease. Saldana, Tina M.; Basso, Olga; Darden, Rebecca; Sandler, Dale P.. Epidemiology. 18(4):501-506, July 2007.