Atheroscler Thromb. 2006 Apr;13(2):95-100.

The use of atorvastatin showed a deterioration of glycemic control in type 2 diabetics.

Atorvastatin is frequently administered for the treatment of hypercholesterolemia associated with type 2 diabetes mellitus. However, a marked deterioration of glycemic control has been reported in some patients treated with atorvastatin.

No study has been done to determine whether atorvastatin adversely affects glycemic control. In this study, we retrospectively compared an atorvastatin-treated group (Group A, n = 76) with a pravastatin-treated group (Group P, n = 78) to examine the effects of the 2 statins on glycemic control from the onset of administration to 3 months thereafter.

No change occurred in the antidiabetic drug dose in 62 patients of Group A and 68 patients of Group P. In those patients, arbitrary blood glucose levels increased from 147 +/- 50 (mean +/- SD) mg/dL to 177 +/- 70 mg/dL in Group A and from 140 +/- 38 mg/dL to 141 +/- 32 mg/dL in Group P. HbA(1c) increased from 6.8 +/- 0.9% to 7.2 +/- 1.1% in Group A and from 6.9 +/- 0.9% to 6.9 +/- 1.0% in Group P. The increase was significant only in Group A, and the extent of the increase was also significantly greater in Group A.

These results suggest a predisposition to a deterioration of glycemic control in type 2 diabetic patients treated with atorvastatin.

Comment by Dr. Robin Conway, Canadian Centre for Research in Diabetes

For some time we have noted in some of our diabetic patients, an apparent decline in glycemic control with addition of a statin and this paper demonstrates that this is indeed the case. Should this inhibit our prescribing of statins for these patients? The new 2006 CDA Clinical Practice Guidelines update on dyslipidemia has set a target of LDL <2 mmol/L which in practical terms means that most (probably >85%) of diabetics should be on a statin. Certainly the value of statin in prevention of cardiovascular death and disease is well proven. We should be aware that the addition of statin may effect glycemic control but rather than avoiding the statin we should be prepared to adjust the dosage of our hypoglycemic agents.