Having a low level of HDL, or “good,” cholesterol, is a risk factor for diabetic nephropathy (kidney disease), according to new research published in the journal Diabetes Care. Diabetes is the leading cause of chronic kidney disease in the United States; between 5% and 15% of people with Type 2 diabetes, and between 25% and 40% of people with Type 1 diabetes, will someday develop diabetic nephropathy.
Diabetic nephropathy begins with changes to the glomeruli, or filtering units, of the kidneys. Over time, the tissue between the blood vessels of the glomeruli may expand, compressing the vessels and reducing their ability to filter waste products from the blood. Eventually, the glomeruli become a mass of scar tissue. Trace amounts of protein in the urine and high blood pressure are signs that a person may have nephropathy.
Low levels of HDL cholesterol are a known risk factor for atherosclerosis, or a buildup of fats and cholesterol in and on the artery walls, but there is little information about the link between low HDL and complications that involve the small blood vessels such as nephropathy. To evaluate the relationship between nephropathy, retinopathy (diabetic eye disease), and HDL cholesterol, researchers followed 11,140 people with Type 2 diabetes and at least one additional blood vessel–related risk factor for a median of five years as part of the Action in Diabetes and Vascular Disease: preterAx and diamicroN-MR Controlled Evaluation (ADVANCE) Study.
The researchers found that 3,585, or 32%, of the participants developed or experienced worsening of a microvascular condition over the follow-up period; 28% of the people had a kidney condition, while 6% had a retinal condition. The third of people with the lowest HDL cholesterol levels had a 19% higher risk of a kidney event than the third of people with the highest HDL cholesterol level. There was no link found between HDL cholesterol and retinopathy.
“Our findings provide the strongest evidence to date for a role of HDL-C [cholesterol] in the development and progression of diabetic nephropathy in patients with Type 2 diabetes,” the researchers note.
According to Harvard Medical School, strategies for raising your HDL levels include getting aerobic exercise such as swimming or bicycling, losing weight, stopping smoking, eating a healthful diet that does not include any trans fats, and taking a medicine such as niacin if recommended by your doctor.
For more information, read the article “Low HDL Cholesterol Ups Risk of Diabetic Nephropathy” or see the study’s abstract in the journal Diabetes Care. And to learn more about keeping your cholesterol levels in a healthy range, see the article “Lifestyle Habits for Lipid Management.”