Very Low Cholesterol Levels Appear to Be Safe

NEW YORK (Reuters Health) - Very low levels of low-density lipoprotein (LDL), the "bad" type of cholesterol, achieved with intensive therapy with cholesterol-lowering drugs called "statins," which include drugs such as Lipitor or Pravachol, appear to be safe for patients with coronary artery disease.

"If the result of the treatment is a very low LDL, it does not appear that there is any major safety concern," Dr. Stephen D. Wiviott from Brigham and Women's Hospital and The TIMI Study Group, Boston, told Reuters Health. "Therefore, there is no reason to dose-reduce the therapy because of the low LDL."

Some previous studies have indicated a possible association between extremely low cholesterol levels and adverse effects such as increased mortality rates and increased rates of optic nerve and retina degeneration.

To further investigate, Wiviott and colleagues used data from 1,825 patients in the PROVE IT-TIMI 22 trial treated with intensive statin therapy to assess the safety and efficacy of achieving very low LDL levels after acute coronary syndrome - heart attack or angina.

Ninety percent of the patients achieved the target LDL level below 100 mg/dL and 10.5 percent achieved LDL levels of 40 mg/dL or lower, the investigators report in the Journal of the American College of Cardiology.

Muscle side effects were infrequent, the results indicate, and there appeared to be no relationship between LDL levels and the development of such side effects. The same was true for liver-related side effects and ophthalmologic events.

There was a trend toward lower rates of death, heart attack and other cardiac events with increasingly reduced LDL level, the researchers note, with the lowest rates in patients with LDL levels between 40 and 60 mg/dL or 40 mg/dL or lower.

LDL level had no apparent effect on overall death rates, the report indicates, but heart attack rates were lower with lower LDL levels.

"Over the past 10+ years, with escalating doses of statin and treatment of patients to lower goals, there have been better outcomes," Wiviott said. "To date, we have not seen a plateau level for LDL and outcomes."

"It appears that 'lower is better' and lower is also safe," Wiviott concluded.

SOURCE: Journal of the American College of Cardiology, October 18, 2005.