Weight loss and incident dementia in elderly Yoruba Nigerians: a 10-year follow-up study.
BACKGROUND
The relationship between weight and dementia risk has not been investigated in populations with relatively low body mass index (BMI) such as the Yoruba. This study set out to achieve this objective using a prospective observational design.


METHODS
The setting was Idikan Ward in Ibadan City, Nigeria. The participants were all aged 65 years or older and were enrolled in the Indianapolis-Ibadan Dementia Project. Repeated cognitive assessments and clinical evaluations were conducted to identify participants with dementia or MCI during 10 years of follow-up (mean duration: 5.97 years). BMI measures, information on alcohol, smoking history, cancer, hypertension, diabetes, heart attack, stroke and depression were collected at each follow-up evaluation. Mixed effect models adjusted for covariates were used to examine the differences in BMI among participants who developed dementia or MCI and those who remained cognitively normal during the follow-up.


RESULTS
This analysis included 1559 participants who had no dementia at their first BMI measurements. There were 136 subjects with incident dementia, 255 with MCI and 1168 with normal cognition by the end of the study. The mean BMI at baseline was higher for female participants (22.31; SD = 4.39) than for male (21.09; SD = 3.61, p < 0.001). A significantly greater decline in BMI was found in those with either incident dementia (p < 0.001) or incident MCI (p < 0.001) compared to normal subjects.


CONCLUSIONS
Decline in BMI is associated with incident MCI and dementia in elderly Yoruba. This observation calls for close monitoring of weight loss in elderly individuals which may indicate future cognitive impairment for timely detection and tailored interventions.
Ogunniyi
Adesola
A
Department of Medicine, College of Medicine, University of Ibadan, Nigeria. aogunniyi892@gmail.com
Gao
Su
S
Unverzagt
Frederick W
FW
Baiyewu
Olusegun
O
Gureje
Oyewusi
O
Nguyen
James Tat
JT
Smith-Gamble
Valerie
V
Murrell
Jill R
JR
Hake
Ann M
AM
Hall
Kathleen S
KS
Hendrie
Hugh C
HC
D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D015992:Body Mass Index; D016009:Chi-Square Distribution; D003072:Cognition Disorders / Q000175:diagnosis / Q000453:epidemiology; D003704:Dementia / Q000175:diagnosis / Q000453:epidemiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D015999:Multivariate Analysis; D009549:Nigeria / Q000453:epidemiology; D012307:Risk Factors; D015431:Weight Loss