Serum leptin levels are associated with cognitive function in older adults.

Recent work suggests that leptin, a circulating adipokinine hormone, might contribute to age-related cognitive decline. The present study investigated the relationship between serum leptin levels and cognitive function in older adults. Thirty-five older adults (73.69+/-6.62 years of age) without significant neurologic or psychiatric history completed a fasting blood draw and a brief neuropsychological test battery. Partial correlations adjusting for demographic and medical conditions showed that higher leptin levels were associated with poorer performance on Trail Making Test B (r = .46, p = .01). These findings indicate that serum leptin levels are negatively associated with speeded executive function in older adults without significant neurological or psychiatric conditions. The mechanisms for this relationship are unknown and require further examination. Such studies may provide key insight into the mechanisms of age-related cognitive decline and identify possible interventions.