During the study period, 1128 subjects aged 65 and older were admitted to the hospital's geriatric ward and were screened. In 63 subjects, data were not recorded, and 97 patients were excluded from the study because of a diagnosis of short-term prognosis tumors (n = 20), blood infections (n = 18), serious anemia (n = 15), disorders of the thyroid (n = 13), primary or secondary malignant brain neoplasms (n = 12), alcohol abuse (n = 10), head trauma (n = 6), and hydrocephalus (n = 3). Thirty-five patients refused to participate in the study. Patients who had stopped smoking during last two years (n = 36) were also excluded from the study, but all of them presented one of the several above-mentioned exclusion criteria or refused to participate in the study. Thus, the final analysis included data from 933 older subjects (394 men, 539 woman, mean age 77.2 ± 6.9, range 65–102 years): 124 patients with dementia (AD = 37 patients, VaD = 45, MD = 42), 98 patients with MCI, and 711 cognitively normal.
shows the mean results of variables, expressed according to the cognitive levels. Patients with dementia had significantly lower MMSE scores (P < 0.001), educational level (P < 0.001), and MNA scores (P < 0.05) and higher CDR scores (P < 0.001), mean age (P < 0.05), and level of disability (P < 0.0001) than patients with MCI or C. No significant differences were found in CIRS severity, CIRS comorbidity, and GDS scores between the three groups. Moreover, MCI patients had significantly lower MMSE and higher CDR scores (P < 0.001) than C, but no significant differences were found in the level of education, mean age, level of disability, and MNA scores between the two groups. Also no significant differences were found among patients with various dementia diagnoses (i.e., AD, VaD, or MD) with regard to the above-mentioned variables.
Demographic and clinical characteristics of patients according to the cognitive levels.
illustrates the distribution of the exposure to cigarette smoking according to the cognitive levels of the sample study. As expected, the frequency of never smokers in the patients without cognitive deficit was significantly higher than that in the patients with dementia and MCI (P < 0.0001; OR = 3.9, CI = 2.1–8.3). However, the frequency of former-active smokers/no SHS in patients with dementia was significantly higher than that in C (P < 0.0001; OR = 2.5, CI = 1.1–5.2), but no significant differences were found between patients with dementia and MCI (P = 0.07; OR = 1.0, CI = 0.5–1.4). Moreover, patients with MCI showed a significantly higher frequency of active smokers that patients with dementia (P < 0.005; OR = 2.3, CI = 1.4–4.5) and C (P = 0.04; OR = 3.0, CI = 1.4–5.9), but no significant differences were found between patients with dementia and C (P = 0.09; OR = 1.0, CI = 0.5–1.6). Similarly, the frequency of the secondhand smokers was significantly higher in the patients with MCI than that in the patients with dementia (P < 0.03; OR = 2.7, CI = 1.5–4.4) or C (P < 0.0001; OR = 1.9, CI = 1.0–3.5), but no significant differences were found between patients with dementia and C (P = 0.19; OR = 0.9, CI = 0.4–1.5). At last, no significant differences were found in frequencies of never smokers, former-active smokers/no SHS, active smokers, and secondhand smokers among patients with various above-mentioned dementia diagnoses.
Cognitive levels and smoking history.