Analizaron datos de 800 monjas, sacerdotes y frailes, todos ellos con ligero sobrepeso de media. Una pérdida de peso de una unidad de índice de masa corporal (IMC) -alrededor de 2 kg- se asoció a un incremento del riesgo de Alzheimer del 35% al cabo de un año.
Cuando comenzó el estudio, ningún participante presentaba demencia y su IMC medio era de 27,4. A lo largo de la investigación fueron diagnosticados de Alzheimer 151 participantes (18,4%).
Neurology 2005;65:892-897
Change in body mass index and risk of incident Alzheimer disease
A. S. Buchman, MD, R. S. Wilson, PhD, J. L. Bienias, ScD, R. C. Shah, MD, D. A. Evans, MD and D. A. Bennett, MD
From the Rush Alzheimer's Disease Center (Drs. Buchman, Wilson, Shah, and Bennett), Departments of Neurological Sciences (Drs. Buchman, Wilson, and Bennett), Behavioral Sciences (Dr. Wilson), and Family Practice (Dr. Shah), and Rush Institute for Healthy Aging and Department of Internal Medicine (Drs. Bienias and Evans), Rush University Medical Center, Chicago, IL.
Address correspondence and reprint requests to Dr Buchman, Rush Alzheimer's Disease Center, Rush University Medical Center, Armour Academic Facility, Suite 1038, 600 S. Paulina St., Chicago, IL 60612; e-mail: Aron_S_Buchman@rush.edu
Objective: To examine the association of change in body mass index (BMI) with risk of Alzheimer disease (AD).
Methods: Nine hundred eighteen older Catholic clergy participating in the Religious Orders Study without dementia at baseline were studied. Outcome measures were the clinical diagnosis of AD and change in cognitive function.
Results: During a mean follow-up of 5.5 years, 151 persons developed AD. BMI averaged 27.4 at baseline and declined in about half the participants. In a proportional hazards model adjusted for age, sex, and education, each 1-unit less of BMI at baseline was associated with about a 5% increase in the risk of AD (hazard ratio = 0.944; 95% CI = 0.908 to 0.981), and each 1-unit annual decline in BMI (about the 10th percentile) was associated with about a 35% increase in the risk of AD compared with a person experiencing no change in BMI (about the 50th percentile) (hazard ratio = 0.730; 95% CI = 0.625 to 0.852). The results were similar after controlling for chronic diseases and excluding persons who developed AD during the first 4 years of observation. Random effects models showed that the rate of cognitive decline increased by about 8% for each 1-unit less of BMI at baseline and declined an additional 40%/year in persons losing 1 unit of BMI/year compared with those with no change in BMI.
Conclusion: Declining body mass index (BMI) is associated with increased risk of incident Alzheimer disease (AD). Loss of BMI may reflect pathologic processes that contribute to the subsequent development of AD.