Tobacco use in Alzheimer's disease

Cholinergic abnormalities in Alzheimer's disease (AD) may be important in the pathogenesis of memory impairment. Tobacco use, which might reflect changes in central nicotinic receptors, was examined by chart review of 272 patients (M:F 86:186) with "probable" AD by NIH criteria, and by interviewing next-of-kin of 39 patients (M:F 15:24) and spouse controls. On chart review, 37% of females and 98% of males had used tobacco, but only 10% of females and 14% of males were still smoking at AD onset. Interval between stopping smoking and AD onset was 18.3 +/- 7.7 years in females and 16.6 +/- 6.8 years in males. Losing the taste for smoking preceded cessation in 60.3% of females and 16.2% of males. Only 7.9% of females and 4.4% of males had withdrawal symptoms. Next-of-kin interview revealed that patients and controls were comparable in demographic data, alcohol use, and smoking habits. 24% of patients and 37% of controls had stopped smoking, often due to losing the taste for smoking (32% of patients; 18% of controls). Withdrawal symptoms occurred in 21% of patients and 41% of controls. Relative to controls, patients less frequently had increased appetite (28% vs 47%), but more often had changed sex drive (22% vs 0%) and altered preference for specific alcoholic beverages (11% vs 0%), after stopping smoking. In AD, the loss of desire to smoke, lack of nicotine withdrawal, and altered appetites long precede cognitive symptoms, suggesting preclinical changes in central nicotinic receptors, as well as possible diagnostic and therapeutic strategies.