The Waste Land: When Diabetes
Shuts Down the Body’s Kidney Function
Fatigue. Nausea. Lack of appetite. Those are the most common symptoms kidney specialist Carlos Marchena, M.D. , notices in patients with diabetes, whose kidney function has declined to the point that they would need dialysis.
"Not everyone with diabetes develops kidney disease," says Dr. Marchena, "and even then, it’s a slow-build up over many years. In fact, in the first years, those with diabetes that develop kidney involvement, have a higher filtering function. That function subsequently declines to levels that alter their well-being. They develop progressive weakness, tiredness, poor appetite, and anemia. Eventually, their kidney disease is a life-threatening situation. At that stage, the patient needs dialysis to prolong life.
- There are different types of diabetes. Type 1, comprises 10% of all patients with diabetes, and results from the destruction of pancreatic cells that produce insulin.
- The other, Type 2, which comprises 80 % of all patients with diabetes, results from variable degrees of insulin resistance. African Americans, Native Americans and Hispanics are more prone to develop end stage kidney failure than non-Hispanic Caucasians.
- About 10% of patients acquire diabetes during pregancy (gestational diabetes). With strict blood sugar control, diabetes goes away once the mother gives birth. Even so, women who have had diabetes while pregnant can be prone to Type 2 diabetes later in life.
- Spilling albumin in urine (microalbuminuria) is the first evidence of kidney damage, due to diabetes (diabetic nephropathy). Subsequently, the amount of proteins in the urine increase (proteinuria), and the capacity of the kidneys to excrete "waste", progressively decreases at variable speeds, over time.
- About 27% of patients diagnosed with diabetes, with no protein in the urine, but poorly controlled blood sugar over a 61/2-7-year period, will develop protein in their urine. However, only 16 % of that number will develop protein in their urine, if their blood sugar was well controlled. Multiple studies have proven that good control of blood sugar prevents or delays the onset of diabetic nephropathy. .If patients with small amounts of albumin in urine (microalbuminuria) are treated with a strict regimen to control blood sugar, the amount of the protein will remain relatively stable, or it may decrease over time. If the blood sugar is not controlled strictly, the amount of the protein in the urine will increase progressively in 6.5 % of patients per year. So, in patients with early diabetic nephropathy, strict control of blood sugar improves or delays progression to renal failure. Once the patient has developed massive proteinuria, strict control of blood sugar may not influence significantly the progression of renal failure. At this stage, good control of blood pressure, and the use of ACE drugs (angiotensive- converting enzyme inhibitors) and/or ARB’s (angiotensive receptor blockers), plus a low protein diet, may play a more important role in slowing the progression of the renal disease, than strict control of blood sugar.
- Strict control of blood sugar, good control of blood pressure and cholesterol, and weight reduction, if indicated, may prevent or slow the progression of microvascular damage to the kidneys, retina and nerves.
- In general terms, about 30 to 40 % of patients with diabetes will develop some evidence of kidney damage, which may progress to end stage chronic renal failure requiring dialysis. In the U.S., about 40 % of all patients on dialysis are diabetic.
Once the patient has developed renal failure, and the renal function is below 30 %, they may start experiencing weakness, tiredness, poor appetite, or anemia. When the renal function declines to about 15 %, they need dialysis to improve the feeling of well-being, and to prolong life.
Dr. Marchena says: "We really encourage everyone, in particular those who have diabetes in their families, to see their doctor regularly and get a test of their blood glucose sugar levels and their renal function. The earlier we catch diabetes, the better able we are to manage or prevent complications. If a person has diabetes, he/she must cooperate closely with their family physician, or diabetic specialist to manage their diabetic treatment."