Risk factors for dementia and impaired cognitive status in Thai elderly

Objective : To examine the association of physical and biochemical risk factors for dementia and cognitive status in an urban population based Thai elderly. Material and Method : This study was part of an integrated health research project from 1997 to 1999. Subjects were 550 elders who lived in a community within 10 km from Siriraj Hospital, Bangkok, Thailand. They were 55 years and older. Thai mental state examination (TMSE) was applied to all subjects as the screening test for dementia. Those who scored less than or equal to 24 out of 30 were categorised as having cognitive impairment or suspected of having dementia, and they were then examined in detail for the diagnosis of dementia using the DSM IV criteria. Blood pressure and body weight were recorded. Blood was drawn for biochemical and haematological analysis including the serology for syphilis and thyroid function test as the basic screening investigation for dementia. Descriptive data, expressed as the mean, standard deviation, Pearson Chi square and ANOVA tests were analysed with SPSS 9.0 in the study. Results : Of 550 subjects, 261 (47.45%) were classified as the normal subjects group, 49 (8.91%) as the cognitively impaired group, and 240 (43.82%) as the dementia group. 377 subjects (68.55%) were female and the distribution of females in each subgroup ranged from 63.3 - 75.5 per cent. The mean age in the normal group was 67.47 ± 6.05 years, the cognitively impaired group was 70.14 years and the dementia group was 69.63 ± 9.21 years. Systolic blood pressure (BP), diastolic BP, serum cholesterol, SCOT, GGT, serum albumin, haemoglobin, MCHC, neutrophil counts and weight were statistically significant factors that were associated with cognitive status. Both systolic and diastolic BP were high in the higher cognitive status group. Serum albumin, serum cholesterol levels and body weight were also higher in the high cognitive status group. Conclusion : This study demonstrated an association between nutritional status and cognitive status in Thai elderly. Poorer nutritional factor in lower cognitive function individuals might explain a lower of both systolic and diastolic BP in the dementia subjects compared to the healthy subjects.