An analysis of dozens of studies found the widely used statin cholesterol drugs do not increase the risk of Lou Gehrig's disease, U.S. health officials said.

The U.S. Food and Drug Administration said it reviewed 41 long-term controlled clinical trials after receiving a higher- than-expected number of reports of Lou Gehrig's disease, or amyotrophic lateral sclerosis, in patients who were treated with the cholesterol-lowering drugs.

Millions of people around the world take statins, including Pfizer Inc's. Lipitor and AstraZeneca Plc's Crestor. US FDA researchers found that nine out of about 64,000 patients treated with statins were diagnosed with ALS, a fatal neurodegenerative disease, during long-term clinical trials. That compared with 10 of 56,000 patients who got placebos.

"The results show no increased incidence of the disease in patients treated with a statin compared with placebo," an FDA statement said. Dr. Mark Avigan, director of pharmacovigilance in the FDA's drug center, said the finding was "reassuring," but added that "given the extensive use of this class of drugs and the serious nature of ALS, continued study of this issue is warranted."

Results from another study by researchers at Stanford University and the health insurer Kaiser Permanente should be available in six to nine months, the FDA said. The agency also is considering additional studies of its own. The FDA analysis was published in the journal Pharmacoepidemiology and Drug Safety.

AstraZeneca spokeswoman Donna Huang said the company's own monitoring and reviews of medical literature "has not identified a causal relationship between ALS and the use of Crestor." More than 13 million patients worldwide have been prescribed the drug, she said. Other statins include Merck & Co Inc's Zocor , sold generically as simvastatin, and Bristol-Myers Squibb Co's , Pravachol, available generically as pravastatin.