Pioglitazone stopped impaired glucose tolerance from converting to type 2 diabetes in 72% of participants in a recent trial funded in part by Takeda Pharmaceuticals, which manufactures Actos (pioglitazone).

Researchers randomized 602 adults with impaired glucose tolerance to pioglitazone treatment or placebo (N Engl J Med. 2011;364:1104-1115). After a median follow-up period of 2.4 years, annual incidence rates for type 2 diabetes were 2.1% in the pioglitazone group and 7.6% in the placebo group. Half of the pioglitazone users converted to normal glucose tolerance, compared with 28% of those taking placebo.

Compared with placebo, pioglitazone significantly reduced fasting glucose levels (by 11.7 mg/dL, vs. 8.1 mg/dL for placebo), two-hour glucose levels (by 30.5 mg/dL, vs. 15.6 mg/dL for placebo), and hemoglobin A1c levels (by 0.04 percentage points, vs. an increase of 0.20 percentage points for placebo).

Pioglitazone also was linked with a 2.0-mm Hg reduction in diastolic BP compared with 0.0 mm Hg with placebo, a greater increase in HDL (7.35 mg/dL vs. 4.5 mg/dL for placebo), and a reduced rate of carotid intima-media thickening (31.5%). However, the pioglitazone patients gained more weight than those taking placebo (8.6 lb vs. 1.7 lb), and had more edema (12.9% vs. 6.4%).

In other diabetes news, the American Academy of Neurology has issued a new guideline on the most effective treatments for painful diabetic neuropathy (PDN). Vera Bril, MD, and coauthors recommend the anticonvulsant pregabalin to relieve the condition because the drug has been established as effective. Other agents deemed “probably effective” were venlafaxine, duloxetine, amitriptyline, gabapentin, valproate, certain opioids, and capsaicin.

The guideline was published online ahead of print by the journal Neurology.