High levels of ceramides, a family of lipids, in the blood of a patient may be predictive of developing Alzheimer's disease.

Dr. Mielke PhD, from the Mayo Clinic (Rochester, MN, USA) and her team conducted a study to see whether blood levels of ceramides and sphingomyelins are associated with increased risk of Alzheimer's disease (AD). Previous studies found links between high serum ceramide levels and memory impairment and hippocampal volume loss.

Participants in a longitudinal, population-based study included healthy women 70 to 80 years of age, living in Baltimore, (Maryland, USA). None had dementia at baseline. The women were followed for up to six visits over nine years. Their blood was collected at baseline and at each subsequent visit. Out of 99 women, 27 (27.3%) developed incident dementia. Of these, 18 (66.7%) were diagnosed with probable Alzheimer's disease.

An increased risk of Alzheimer's disease was associated with higher baseline serum ceramides. However, higher levels of sphingomyelins were not linked to increased Alzheimer's disease risk. The team also noted that women in the middle tertile of serum ceramide levels had the highest risk for Alzheimer's versus those in the lowest tertile, with an intermediate increased risk seen among those in the highest tertile.

Michelle M. Mielke said, "The study is small—that's a limitation, and it was a preliminary study. However, given the small sample size, to have hazard ratios that are near 10 was quite striking and we didn't expect to see that at all," said Dr. Mielke. "Pretty much any marker is not going to be associated with a 10-fold risk, so yes, this does need to be replicated in another study, but it suggests to us that plasma or blood ceramide levels are associated with an increased risk of Alzheimer's disease," she said.

According to Valory Pavlik, PhD, of the Alzheimer's disease and memory disorders center at Baylor College of Medicine (Houston, TX, USA) the study findings are noteworthy. Identification of an accurate biomarker to predict Alzheimer's disease that can be obtained with a minimum of cost and inconvenience to a patient, could lead to model focused on preventing or delaying disease onset.

Related Links:
Mayo Clinic
Baylor College of Medicine