Estimated Creatinine Clearance and Cognitive Impairment in Thai Older Adults: A Pilot Study from the Dementia and Disability Project in Thailand
Prachaya Srivanitchapoom MD*, Vorapun Senanarong MD*
Affiliation : * Division Neurology, Department Medicine, Factory Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
Background : Chronic kidney disease and dementia are the two common conditions in the older adults. The recent study from
the US older adult populations has shown that the lower levels of kidney function are associated with increased prevalence of
cognitive impairment.
Objective : Exploring the relationship between levels of kidney function and cognitive function in Thai community base older
adults and finding the threshold of kidney function for which general practitioner should screen for cognitive impairment.
Material and Method: Bangkok community dwelling older adults were recruited during 2004-2006. Serum creatinine and
cognitive function were measured. Kidney function was represented in estimated creatinine clearance (eCrCl), calculated by
Cockcroft-Gault formula. Cognitive function assessment was evaluated by Mini Mental State Exam Thai version (TMSE).
The participants were divided into 4 groups, Model 1, those stratified by level of eCrCl; > 90, 60-89, 30-59 and < 30 mL/min
respectively. Unfortunately, after the authors categorized eCrCl as a Model 1, the number of participants are largely
unequally distributed among the 4 groups. Therefore, the authors developed Model 2. In Model 2, eCrCl was divided, by
tertile, into 3 groups; eCrCl > 65, 48-65 and < 48 mL/min respectively. Participants with TMSE < 24 were considered to have
cognitive impairment. The association between kidney function and cognitive impairment was determined by univariable and
multivariable logistic regression models.
Results : 317 participants were enrolled, 65.71% (n = 207) were women. The mean age was 71.13 years (SD = 7.99). In
Model 1, the authors found a trend which indicated that eCrCl < 30 mL/min increased the prevalence of cognitive impairment
when compared with eCrCl > 90 mL/min (adjusted odds ratio 3.82; 95% CI 0.90-16.19, p-value = 0.07). In Model 2, the
authors also found that populations of eCrCl < 48 mL/min had a trend to increase the prevalence of cognitive impairment
when compared with eCrCl > 65 mL/min (adjusted odds ratio 1.76; 95% CI 0.99-3.12, p-value = 0.052).
Conclusion : In the present study, the authors could not demonstrate any statistical significant of an association between the
lower eCrCl and cognitive impairment. However, the authors found that eCrCl < 48 mL/min may have a trend to associate
with cognitive impairment. Therefore, the authors may use this eCrCl level for screening prevalence of cognitive impairment
in the older adult population.
Keywords : Creatinine clearance (CrCl), Chronic kidney disease (CKD), Cockcroft-Gault formula, Cognitive impairment and Mini Mental State Exam Thai version (TMSE)
