Getting to the bottom of diabetes and kidney disease
Renal cells called podocytes may need insulin to maintain blood-filtration role
By Nathan Seppa
Diabetic kidney disease may result as much from a failure of certain renal cells to access insulin as it does from runaway blood sugar, a new study shows. The findings in mice suggests that targeting the condition known as insulin resistance might protect the kidneys of people with diabetes, researchers report in the October Cell Metabolism.
Fully half of all kidney disease that leads to dialysis or a transplant occurs in people with diabetes, and most have the common type 2 form that typically shows up in adulthood. Type 2 diabetes has clear links to obesity, lack of exercise and insulin resistance in which cells fail to capture glucose efficiently from the bloodstream after digestion of food. While the precise cause of insulin resistance remains unclear, there’s no question it starves cells, forces the pancreas to work overtime making more insulin and leaves a person with high blood sugar.
In the new study, researchers investigated a role for insulin resistance in kidney failure by examining cells called podocytes that form part of the blood-cleansing apparatus of the kidneys. Podocytes look like miniature octopuses layered over capillaries in the kidneys, with extensions that snag useful proteins from blood but allow water and waste products to pass through and into the urine. “It’s a biological sieve,” says pediatric nephrologist Richard Coward of the University of Bristol in England.