Serum leptin and cognitive function in people with Type 2 diabetes

People with obesity and type 2 diabetes are at increased risk of cognitive impairment. We aimed to investigate the association of leptin with cognitive abilities in an elderly population with type 2 diabetes. We performed a cross-sectional study of 1057 men and women aged 60-75 years with type 2 diabetes living in Lothian (Scotland). A cognitive battery was administered. Prior intelligence was estimated from vocabulary testing and adjustment for scores on this test was used to estimate lifetime cognitive change. Relationships between fasting morning leptin levels and cognitive ability and estimated cognitive change were tested. Higher leptin levels were associated with significantly poorer estimated overall cognitive decline, and poorer performance in 2 cognitive domains assessing mental flexibility and executive function, only amongst men (p < 0.05). High morning leptin levels in elderly men with type 2 diabetes are associated with estimated age-related cognitive change.