ALS: Diabetes Type 2 Protects Patients

People who have type 2 diabetes—but not type 1—are statistically less likely to get amyotrophic lateral sclerosis (ALS), a new study found.

Writing in JAMA Neurology Marianthi-Anna Kioumourtzoglou, ScD and colleagues at Harvard’s Chan School of Public Health in Boston, MA and colleagues there and in Denmark analyzed data from the Danish National Registers.

They looked at hospital admissions and discharge data for 3,650 Danish resident with ALS and 365,000 controls matched for age and sex.

They found a “strong protective association between prior diabetes-related [hospital] admissions and ALS,” the team wrote.

In looking for reasons for the phenomenon, the authors said “The underlying pathophysiological mechanisms of ALS are likely multifactorial, with defective energy metabolism and homeostasis likely playing an important role in pathogenesis.” Clues may lie in the fact that ALS is more prevalent in people with a low BMI and who are very active physically, they said.

“It is possible that associations with BMI and diabetes are simply the result of their own association with physical activity,” they noted.

Side effects of diabetes medications could also be playing a role. Or it could be that high levels of uric acid found in type 2 diabetes is protective in ALS.

The researchers found the opposite association between ALS and type 1 diabetes. That form of diabetes is a risk factor ALS.

That might be because patients with this ailment have low levels of uric acid.

In conclusion, the team wrote that the finding that type 2 diabetes is protective against ALS and type 1 diabetes is a risk factor shows that metabolism is a key player in who develops the neuro-degenerative disease.

“Although the mechanisms underlying this association remain unclear, our finding focus further attention on the role of energy metabolism in ALS pathogenesis,” they wrote.