Very low cholesterol levels appear to be safe

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,” said Dr. Stephen D. Wiviott from Brigham and Women’s Hospital and The TIMI Study Group, Boston. “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.

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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.

Cholesterol levels are determined through chemical analysis of a blood sample taken from a finger prick or from a vein in the arm. Home cholesterol kits, first approved in 1993, test only for total cholesterol levels but are as accurate as tests done in a doctor’s office, says Steven Gutman, M.D., director of FDA’s division of clinical laboratory devices.

“These tests can give a consumer very valuable information when screening for High cholesterol,” he says. “But they shouldn’t be considered substitutes for a test conducted in a doctor’s office.” He adds that if test results are elevated, consumers should see a doctor right away for a more refined blood analysis. The National Cholesterol Education Program considers cholesterol testing in a doctor’s office to be the preferred way because the patient can get advice immediately about the meaning of the results and what to do.

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.

A healthy LDL level is one that falls in the optimal or near-optimal range.

  • Optimal: Less than 100 mg/dL
  • Near Optimal: 100-129 mg/dL
  • Borderline High: 130-159 mg/dL
  • High: 160-189 mg/dL
  • Very High: 190 mg/dL and higher

“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.

Provided by ArmMed Media
Revision date: June 21, 2011
Last revised: by David A. Scott, M.D.