Surprising Effects of Statins

Side effects aren’t always a bad thing. Statin drugs were developed to help lipid (blood fat) levels. They lower low-density lipoprotein (LDL) cholesterol levels. Because of these positive effects on blood lipids, statins have become the drug of choice for people with diabetes whose cholesterol levels are too high.

But research suggests that statins may also have useful side effects: They may reduce the chance of broken bones in older people and possibly the risk of dementia as well.

Bones

Osteoporosis (loss of bone mass leading to fragile bones that break easily) is a serious problem in older Americans, afflicting 8 million women and 2 million men. Finding ways to stop or reverse bone loss would greatly help many people.

One small study of statins and bones in the March 2000 Journal of Clinical Endocrinology and Metabolism focused on people with diabetes. Researchers examined the hospital records of 69 Koreans with type 2 diabetes. About half took statins; the others (control subjects) had normal cholesterol levels. The two groups started the study with no difference in bone density. But after more than a year, women control subjects had lost bone from the spine. Meanwhile, men and women taking statins had increased the density of the upper end of the shaft of their thigh bones.

By contrast, the only other study with people with diabetes, reported in the Oct. 9, 2000, Archives of Internal Medicine, found lower bone density in 440 Japanese people with type 2 diabetes who took statins.

Several studies have been done in the general population. Some (but not all) did find that people taking statins had either better bone density or fewer broken bones. In these studies, other lipid- lowering drugs seemed not to have the same benefit.

Dementia

Four recent research studies suggest that people who take statins lower their risk of dementia.

* An October 2000 study in Archives of Neurology looked at 57,000- plus hospital patients. Probable Alzheimer’s disease was diagnosed significantly less often in statin users than in the others.

* A November 2000 study in Lancet looked at 1,364 people 50 to 89 years old. People on statins had a significantly lower risk of getting dementia than people taking other lipid-lowering drugs or not taking any lipid drugs.

* A February 2002 study in Archives of Neurology looked at 2,305 people 65 or older. People younger than 80 who took statins or any other lipid-lowering drugs were much less likely to get Alzheimer’s or other forms of dementia.

* A March 2002 study in Archives of Neurology looked at 1,037 postmenopausal women younger than 80 who had heart disease. The quarter of women with the highest total and LDL cholesterol levels were almost twice as likely to be cognitively impaired. Women taking statins were less likely than other subjects (but not significantly so) to develop dementia. Women taking other cholesterol drugs did not have a lower dementia risk.

These results suggest statins lower the risk of dementia, whereas other cholesterol drugs might not. But further studies are needed: Some small trials did not find a link between statins and a lower risk of dementia.

A New Concern

Unfortunately, not all new research on statins has found such happy results. In a study published in the May 2002 Neurology, researchers looked at medical and prescription records of 166 people likely to have peripheral polyneuropathy (damage to multiple nerves outside the brain and spinal cord) of no known cause. (In other words, the polyneuropathy was not caused by diabetes or some other known condition.) For each patient the researchers chose 25 people of the same sex and age, but without polyneuropathy, for comparison.

The researchers found that 5.4 percent of the people likely to have polyneuropathy were taking statins versus only 1.2 percent of those without polyneuropathy (the control group). Those with definite polyneuropathy were found to be 16 times as likely to be taking statins as those who did not have nerve disease (the control group). The researchers concluded that long-term use of statins may substantially increase the risk of polyneuropathy.

Even so, the researchers concluded statins’ benefits far outweigh the risk of neuropathy. Despite their many benefits, statins are not risk-free. They can also interact with several other drugs and can cause neuropathy and other side effects (see “A Statins FAQ,” November 2001 Diabetes Forecast, page 25).

Conclusions

Statins are already the first-choice drugs to use in people with diabetes who have high LDL cholesterol (see box, lower left). The new studies show that statins likely have additional benefits that far outweigh their risks, strengthening their position as a first- choice drug.

The statins include:

* Atorvastatin (Lipitor)

* Fluvastatin (Lescol)

* Lovastatin (Mevacor)

* Pravastatin (Pravachol)

* Rosuvastatin (Crestor)

* Simvastatin (Zocor)

If future research confirms that statins do indeed build bone or maintain mental abilities, research will be needed to learn whether there are differences among the statins regarding their effects and what doses are best.

ADA recommends…

The Association recommends that all adults with diabetes be checked annually for lipid disorders. Goals are an LDL of less than 1OO mg/dl, an HDL above 50 mg/dl, and triglycerides less than 150 mg/ dl. If these goals are not met, lifestyle interventions (reduction of saturated fat and cholesterol intake, weight loss, increased exercise, and smoking cessation) should be initiated. If these fail, drug therapy should be considered.

Among those with diabetes over age 40, the Association recommends statin therapy for those whose total cholesterol is above 135 mg/ dl.

BY SHAUNA S. ROBERTS, PhD

Shauna S. Roberts, PhD, is a science writer in New Orleans, La.

Copyright American Diabetes Association Nov 2004