Tuesday, November 18, 2008

Melamine, Diabetes, Kidney Disease, and Heart Disease

One reason I'm distracted by this melamine story is that I have a history of working with people with diabetes. People with diabetes are prone to kidney problems. (Diabetes drives progression of atherosclerosis, which narrows arteries all over the body, especially tiny arteries in the kidneys.) In fact, diabetic nephropathy (diabetes-related kidney disease) is the leading cause of kidney failure (non-acute) in the US right now.

So, a chronic, low-level presence of melamine in food is going to present a greater challenge for people with diabetes, or for anyone with a chronic kidney condition.

Having high blood pressure (over 120/80)1 in addition to diabetes will accelerate kidney damage. Just having high blood pressure alone - without a diagnosis of diabetes - can damage kidneys. It strains the tiny blood vessels that make up a kidney filtering unit - a glomerulus (I swear after all these years I still have difficulty pronouncing that word). Lose the function of enough of your glomeruli and you're on dialysis.

Also, having kidney disease (whose symptoms are often silent) accelerates heart disease. Conversely, cardiovascular disease accelerates kidney disease.2

These conditions are all linked. Melamine can cause kidney disease or can accelerate kidney disease if you already have it, and kidney disease can accelerate heart disease. It's not a stretch to hypothesize that chronic low levels of melamine could contribute to heart disease.

According to this article that appeared in the New York Times yesterday (sent in by reader BL):
Kidney Disease Takes a Growing Toll
"We’ve had a marked increase in chronic kidney disease in the last 10 years."
... a lot more people are going to have difficulty handling contaminants like melamine in their food.

We really need to ascertain levels of melamine in food.

If you're concerned about your kidneys, there are three tests I know of that can judge their function:
  1. Check the rate at which kidneys filter blood, a GFR (Glomerular Filtration Rate), requires a blood sample.
  2. Check levels of protein (albumin) in the urine.
  3. Check for anemia, specifically hemoglobin. The kidneys make a hormone, called erythropoietin (a word I can pronounce, really) that stimulates production of red blood cells. By the way, this is a reason people with kidney problems are often tired.
You could also have a scan or biopsy done, but those are more invasive.
1 Technically 120/80 to 149/90 is called prehypertension.
2 Independent Components of Chronic Kidney Disease as a Cardiovascular Risk State, Archives of Internal Medicine, June 2007.

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