When coerced into giving a talk at the hospital, there’s only one option—turn it into a blog post. So here it is—a 40-minute talk on diabetes and kidney disease condensed into a 5-minute read. (What does that say about the talk?)
The absolute basics
Diabetes mellitus is a disease in which the body’s ability to produce or respond to a hormone called insulin is impaired. The result is high blood sugar (glucose) that can subsequently damage various parts of the body, in this case the kidneys.
A bit on kidney disease
The kidneys are two bean-shaped organs tasked with removing waste products and excess fluid from the bloodstream. That which is not required is excreted in the form of urine.
Performing the all-important task of filtering the blood are tiny filtering units called nephrons—each kidney has around one million of them. Damage to the nephrons can result in chronic kidney disease (CKD), something that is said to affect one in seven US adults. Causes are myriad, though the most common is diabetes (i.e. high blood sugar).
CKD can be staged—stage 1 being the earliest and stage 5 being the latest—using simple blood and urine tests.
Preventing progression
Once CKD is diagnosed, the goal is to prevent progression through the stages. In the case of CKD due to diabetes, a few strategies can be employed.
Sugar control
Lowering blood sugar to desired levels can slow or halt CKD progression, at least in the early stages.
Blood pressure control
High blood pressure, which is often seen in the setting of diabetic kidney disease, can itself lead to CKD progression. Controlling blood pressure, preferably to less than 130/80, can be helpful in this regard.
Lifestyle changes
Smoking cessation and weight loss (if appropriate) can slow CKD progression. As cardiovascular disease is more common in those with kidney disease, exercise can be an important part of overall health.
Medications
- ACE inhibitors or ARBs: These two related classes of medications are used to control blood pressure. They have the added benefit of sending a signal to remaining nephrons to not work as hard. While this leads to a decline in kidney function in the short term, the result is nephron preservation in the long term. One class or the other is used, but not both simultaneously.
- SGLT2 inhibitors: This group of medications was designed to treat diabetes by promoting increased sugar excretion in the urine. It turns out that via another mechanism, SGLT2 inhibitors also send a signal to nephrons to not work as hard, resulting in the same long-term benefit mentioned above.
- Nonsteroidal selective mineralocorticoid receptor antagonists: In those who are not eligible for SGLT2 inhibitors, there is evidence that this class of medications can slow CKD progression.
Dialysis
Unfortunately, despite the best of intentions, kidney disease can progress. If severe enough, dialysis can be required to replace kidney function. In other words, artificial means are used to remove waste and fluid from the blood.
Here is a more thorough explanation.
Unfortunately, those with diabetic kidney disease who require such intervention have a five-year survival under 40 percent.
Transplant
Five-year survival with transplant exceeds that seen on dialysis, and the best outcomes are seen in those who receive a transplant prior to ever receiving dialysis (a so-called preemptive transplant). Of course, the lack of readily available organs makes this path unfeasible for many.
Ironically, immunosuppressive medication—used to prevent transplant rejection—can increase blood sugar and lead to scarring in the new kidney.
The bottom line
Don’t get diabetes.
If you do, treat it early and well.
Oh, and a 40-minute talk on diabetes and kidney disease can be condensed into a 5-minute read.
