Central obesity, leptin and cognitive decline: the Sacramento Area Latino Study on Aging

Abstract

Background/aims: Central obesity is a risk factor for cognitive decline. Leptin is secreted by adipose tissue and has been associated with better cognitive function. Aging Mexican Americans have higher levels of obesity than non-Hispanic Whites, but no investigations examined the relationship between leptin and cognitive decline among them or the role of central obesity in this association.

Methods: We analyzed 1,480 dementia-free older Mexican Americans who were followed over 10 years. Cognitive function was assessed every 12-15 months with the Modified Mini Mental State Exam (3MSE) and the Spanish and English Verbal Learning Test (SEVLT).

Results: For females with a small waist circumference (≤35 inches), an interquartile range difference in leptin was associated with 35% less 3MSE errors and 22% less decline in the SEVLT score over 10 years. For males with a small waist circumference (≤40 inches), an interquartile range difference in leptin was associated with 44% less 3MSE errors and 30% less decline in the SEVLT score over 10 years. There was no association between leptin and cognitive decline among females or males with a large waist circumference.

Conclusion: Leptin interacts with central obesity in shaping cognitive decline. Our findings provide valuable information about the effects of metabolic risk factors on cognitive function.

Copyright © 2012 S. Karger AG, Basel.

Figures

Figure 1

Multivariable-adjusted associations of Log Leptin (25th and 75th Percentiles) with change in cognitive function among females from linear mixed effects models, stratified by waist circumference, SALSA, 1998–2008 (based on Table 2). Panel (A) illustrates associations of log leptin percentiles with log 3MSE errors over time within females with small waist circumference (β leptin by age interaction: P<0.05). Panel (B) illustrates associations of log leptin percentiles with log 3MSE errors over time within females with large waist circumference (β leptin by age interaction: P>0.05). Panel (C) illustrates associations of log leptin percentiles with change in SEVLT score over time among females with small waist circumference (β leptin by age interaction: P<0.05). Panel (D) illustrates associations of log percentiles with change in SEVLT score over time among females with large waist (β leptin by age interaction: P>0.05). 25th percentile of leptin= 2.7ng/ml and 75th percentile of leptin=3.6ng/ml. Small waist ≤35 inches and large waist >35 inches. 3MSE, Modified Mini Mental State Exam; SALSA, Sacramento Area Latino Study on Aging; SEVLT, Spanish English Verbal Learning Test.

Figure 2

Multivariable-adjusted associations of Log Leptin (25th and 75th Percentiles) with change in cognitive function among males from linear mixed effects models, stratified by waist circumference, SALSA, 1998–2008 (based on Table 3). Panel (A) illustrates associations of log leptin percentiles with log 3MSE errors over time within males with small waist circumference (β leptin by age interaction: P<0.05). Panel (B) illustrates associations of log leptin percentiles with log 3MSE errors over time within males with large waist circumference (β leptin by age interaction: P>0.05). Panel (C) illustrates associations of log leptin percentiles with change in SEVLT score over time among males with small waist circumference (β leptin by age interaction: P<0.05). Panel (D) illustrates associations of log percentiles with change in SEVLT score over time among males with large waist (β leptin by age interaction: P>0.05). 25th percentile of leptin= 1.6ng/ml and 75th percentile of leptin=2.5ng/ml. Small waist ≤40 inches and large waist >40 inches. 3MSE, Modified Mini Mental State Exam; SALSA, Sacramento Area Latino Study on Aging; SEVLT, Spanish English Verbal Learning Test.