Tin and fatty acids in dementia.

Serum elements and fatty acids of red cell and plasma phospholipids, cholesterol esters and high density lipoproteins, were studied in patients with Alzheimer's disease (SDAT) and with multi-infarct dementia (MID). Increased 20:4n6 in MID was the finding most consistent in the different tissues. The red cell phospholipids were more unsaturated in MID than in SDAT but in SDAT the plasma phospholipids were more saturated. Serum Al, Sn and V concentrations were higher in SDAT than in MID while serum Mn concentrations were higher in MID. Sn and V correlated negatively with the unsaturation index of the red cell phospholipids and Sn showed a striking pattern of correlations with the red cell phospholipid fatty acids in SDAT: it was significantly positively correlated with 16:0 and 18:1n-9 and negatively correlated with 20 and 22 carbon n-3 and n-6 essential fatty acids. Since we have shown elevated tin levels in patients with Alzheimer's disease, and since organic tin compounds given to animals produce a syndrome with similarities to Alzheimer's disease, there is a need for investigation of the role of tin in lipid metabolism in dementia.