title: The role of obesity in cognitive dysfunction in people with epilepsy.
abstract: OBJECTIVE
  In the general population, obesity is associated with accelerated age-related cognitive decline. The impact of obesity on cognitive function in neurological populations who already have a heightened risk of cognitive decline is unknown. This study explored the relationship between obesity and cognitive underfunction in people with medically intractable epilepsy.
  
  
  METHODS
  Eighty-one consecutive patients admitted for evaluation for medically intractable epilepsy (36 females and 45 males) underwent tests of memory and intellectual function. Optimal level of function was assessed using the National Adult Reading Test - Revised. Measures of underfunction were calculated by subtracting current measures of intellectual ability from the NART IQ. Body mass index (BMI) was used as an index of obesity.
  
  
  RESULTS
  Twenty-nine people had a BMI in the healthy range (36%), 31 were overweight (38%), and 21 were obese (26%). The healthy weight, overweight, and obese groups did not differ in age at the time of assessment, age at seizure onset, or optimal level of function (NART IQ). The obese group had a greater degree of suboptimal processing speed and demonstrated a greater degree of underfunction on the Full Scale IQ (FSIQ) measure compared to the healthy weight group. Body mass index accounted for 14% of the variance in underfunction in processing speed and 10% of the variance in underfunction in FSIQ. Controlling for the effects of age, all measures of memory function were significantly correlated with BMI, with poorer scores associated with higher BMIs.
  
  
  CONCLUSIONS
  A small but significant proportion of the variance in memory function and intellectual underfunction in people with epilepsy is explained by BMI. Further work is needed to establish whether a reduction in BMI to within healthy limits is associated with improvements in cognitive function in this group.
authors.affiliation: Department of Clinical and Experimental Epilepsy, Institute of Neurology, UCL, UK. Electronic address: s.baxendale@ucl.ac.uk.
authors.forename: Sallie
authors.initials: S
authors.lastname: Baxendale
authors.affiliation: Epilepsy Society, Chalfont St Peter, Buckinghamshire, UK.
authors.forename: Katherine
authors.initials: K
authors.lastname: McGrath
authors.affiliation: Epilepsy Society, Chalfont St Peter, Buckinghamshire, UK.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Donnachie
authors.affiliation: Epilepsy Society, Chalfont St Peter, Buckinghamshire, UK.
authors.forename: Sue
authors.initials: S
authors.lastname: Wintle
authors.affiliation: University College Hospital, London, UK.
authors.forename: Pamela
authors.initials: P
authors.lastname: Thompson
authors.affiliation: University College Hospital, London, UK.
authors.forename: Dominic
authors.initials: D
authors.lastname: Heaney
mesh_terms: D000328:Adult; D015992:Body Mass Index; D001835:Body Weight / Q000502:physiology; D003071:Cognition / Q000502:physiology; D003072:Cognition Disorders / Q000150:complications / Q000175:diagnosis / Q000523:psychology*; D015331:Cohort Studies; D004827:Epilepsy / Q000150:complications / Q000175:diagnosis / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology; D008875:Middle Aged; D009765:Obesity / Q000150:complications / Q000175:diagnosis / Q000523:psychology*; D055815:Young Adult
keywords: Body mass index; Cognitive function; Comorbidity; IQ; Memory