Starting at midlife, increasing weight loss per decade may increase a person’s risk of mild cognitive impairment (MCI), according to a study published in JAMA Neurology.
The population-based, prospective study included participants aged 70 years or older from the Mayo Clinic Study of Aging. Using medical records, the researchers recorded participants’ maximum height and weight during midlife (ages 40 to 65).
Each participant underwent a cognitive evaluation at baseline and every 15 months thereafter. From the 1,895 participants who were cognitively normal at baseline, 524 developed MCI during an average follow-up of 4.4 years. Risk factors for developing MCI included older age, carrying the APOE ε4 allele, diabetes, hypertension, stroke, and coronary artery disease.
Participants who developed MCI had an average weight change of -4.4 lbs per decade compared with -2.6 lbs per decade for participants who remained cognitively normal. The risk of developing MCI increased as weight change increased; a loss of 11 lbs per decade represented a 24% increased risk of developed MCI.
The researchers noted that they could not determine whether this weight loss was intentional.
“In summary, our findings suggest that an increasing rate of weight loss from midlife to late life is a marker for MCI and may help identify persons at increased risk of MCI,” the study authors wrote.
Approximately 5% to 15% of people with MCI develop dementia each year. Changes in BMI and weight have been linked to an increased risk of dementia, but current evidence is still inconclusive. Because MCI is a prodromal stage of dementia, an association between weight loss and MCI could provide new research avenues for prevention.
- Alhurani RE, Vassilaki M, Aakre JA, et al. Decline in Weight and Incident Mild Cognitive Impairment: Mayo Clinic Study of Aging. JAMA Neurol. Published online February 1, 2016. doi:10.001/jamaneurol.2015.4756.