Does the addition of a statin drug to standard therapy reduce kidney disease in patients with diabetes?

This study examined if adding atorvastatin (Lipitor) to irbesartan (Avapro) helped reduce early kidney disease in patients with diabetes.  The authors found that adding atorvastatin reduced a number of symptoms of kidney disease for these patients.

Patients with diabetes mellitus often experience complications, including kidney disease.  Kidney disease that is caused by diabetes is called diabetic nephropathy. This condition affects normal kidney function and can lead to kidney failure. Approximately 20% of patients with diabetes eventually develop end-stage renal disease.

Studies suggest that controlling cholesterol levels may help slow down the progression of kidney disease. Recently, a statin drug called atorvastatin has shown promise in reducing the symptoms of kidney disease when used with irbesartan. The effectiveness of this treatment combination for patients with diabetes is under investigation.

This study analyzed the results of 17 studies. These studies compared irbesartan plus atorvastatin versus irbesartan alone in patients with diabetes.  1390 patients were included in this analysis.  Patients were treated for an average of 12 weeks to 6 months.

Adding atorvastatin to irbesartan significantly reduced the amount of protein found in the urine (a symptom of kidney disease) by 21.22 units. After more than 3 months of treatment, this reduction was higher (24.20 units).

Adding atorvastatin to irbesartin also decreased creatinine levels in the blood. High levels of creatinine in the blood indicate that kidney function is slowing down. Creatinine levels in the blood decreased by 6.46 units. After more than 3 months of treatment, this reduction was higher (8.11 units).

Adding atorvastatin to irbesartin also reduced the levels of fats found in the blood (another symptom of kidney disease) compared to irbesartan alone.  Triglycerides were significantly reduced by 1.79 units and cholesterol was reduced by 0.93 units.

When there is inflammation in the body such as from kidney disease, the levels of certain molecules in the blood increase. Adding atorvastatin decreased CRP levels by 1.57 units. IL-6 levels decreased by 1.53 units.  Blood pressure was also reduced by 2.27 mmHg.

Overall, side effects were mild and rare. The most common side effects were nausea, vomiting, and dizziness. Adding atorvastatin to irbesartan was significantly associated with a 3.15-fold higher risk of nausea and vomiting compared to irbesartan alone.

The authors concluded that adding atorvastatin to irbesartan helped reduce symptoms of early kidney disease in patients with diabetes.  However, it was associated with increased nausea and vomiting.

All the studies analyzed here included Chinese patients. These results may not apply to all patients. Also, the follow-up time was short. More studies with a longer follow-up are needed to confirm these results.