Using Anti-diabetics, Cholesterol-lowering Medicines May Affect Risk of ALS

People with amyotrophic lateral sclerosis (ALS) are less likely to have used anti-diabetic medications in the five years preceding their diagnosis than matched individuals of the same population, a study found, supporting an inverse association between diabetes treatments and the risk of ALS.

The research also points to an increased use of statins in women in the year before their ALS diagnosis, which may indicate that statin use accelerates disease course.

Those findings were revealed in the study, “Antidiabetics, statins and the risk of amyotrophic lateral sclerosis,” which was published in the European Journal of Neurology.

People with ALS experience changes in metabolism long before their disease is diagnosed. This is evidenced by the higher levels of LDL (the so-called “bad” type of cholesterol) about two decades before ALS diagnosis and the negative association between long-term type 2 diabetes and the risk of developing the neurological condition.

Medications used to treat diabetes have been suggested as protective factors for ALS, while those used to lower cholesterol levels (statins) are believed to have detrimental effects. However, current data is conflicting, with some studies suggesting the opposite associations.

In an attempt to clarify these associations, researchers examined data from 2,475 ALS patients, diagnosed in Sweden from July 2006 to December 2013, and assessed if they had been prescribed any anti-diabetics (particularly insulin, metformin and sulfonylureas) or statins in the eight years preceding their diagnosis.

The team then compared these prescriptions with those of 12,375 controls (five controls for each patient), who were matched to patients in terms of age, sex, and area of residence.

ALS patients were about 29% less likely to have been prescribed anti-diabetics in the five years before their diagnosis than controls, suggesting that the long-term use of these medications may somehow protect people from ALS.

This protective effect was seen regardless of sex, age, and the kind of anti-diabetics used, but the strongest association was noted for sulfonylureas, which remained significant even after adjusting for use of statins and other anti-diabetic medications.

“The inverse association of antidiabetics with ALS is consistent with the previously reported inverse association between type 2 diabetes and ALS risk,” the researchers wrote.

The prescription of statins was not significantly different among controls and the overall group of patients, but the team found some subgroups where statin use increased the risk of ALS. This was the case for women, who had a 28% higher risk of ALS when prescribed these medications, and for patients younger than 62 years whose use of statins increased the risk of ALS by 38%.

People receiving statins in the year before their diagnosis were 2.5 times more likely to develop ALS. While the reason for this might be that metabolic changes are detected about one year before clinical evaluation for ALS, this “positive association might also support the hypothesis that statins accelerate the disease course of ALS and symptom onset,” the researchers wrote.

“In conclusion, a clear inverse association of antidiabetics with ALS was noted [and] an increased use of statins during the year before ALS diagnosis was found, especially among women,” they concluded.

Further studies are now needed to understand the biological mechanisms behind these associations, and whether diabetes medications can be used to protect people from ALS and if statins accelerate disease progression.