The purpose of this study is to determine if there are differences in cognitive function (thinking) in individuals who have recurrent hypoglycemia (low blood sugars) following Roux-en-Y gastric bypass, compared with individuals who have also had a Roux-en-Y gastric bypass but do not have hypoglycemia.
This study will test the hypothesis that a history of recurrent hypoglycemia following gastric bypass is associated with differences in cognition (thinking), by analyzing results of cognitive testing in post-gastric bypass individuals with a history of hypoglycemia as compared to those without known hypoglycemia. This pilot study will identify cognitive domains of interest, as well as inform the development of a future battery of assessments, which could be replicated in a larger sample. Cognitive domains which will be assessed include: premorbid intelligence, memory, language, executive function, and psychomotor speed.
Study Type
OBSERVATIONAL
Enrollment
22
Cognitive testing will assess premorbid intelligence, working memory and attention, verbal memory and delayed memory, executive function, and psychomotor speed.
ECG will take place during screening visit.
Joslin Diabetes Center
Boston, Massachusetts, United States
Assessment of Immediate Verbal Memory
Rey Auditory Verbal Learning Test (RAVLT) immediate recall accuracy scores was used to measure immediate verbal memory. Scores for this assessment were compared between groups. Scores for this assessment range 0 to 69, with a higher score indicating a superior immediate verbal memory. Wilcoxon rank-sum tests was used to examine differences between groups.
Time frame: During the one day of cognitive assessment administration.
Assessment of Delayed Verbal Memory
RAVLT 20 minute recall accuracy scores, was used to measure delayed memory and was compared between groups. Scores for this assessment range 0 to 15, with a higher score indicating less delays in memory. Wilcoxon rank-sum tests was used to examine differences between groups.
Time frame: During the one day of cognitive assessment administration.
Working Memory Assessed by the Letter Number Sequencing Scaled Score
Letter-Number Sequencing subtest from the Wechsler Memory Scale III scaled scores were used to measure working memory and were compared between groups. Wilcoxon rank-sum test was used to examine differences between groups. Scores for this assessment range 1 to 19, with a higher score indicating a superior working memory.
Time frame: During the one day of cognitive assessment administration.
Assessment of Cognitive Flexibility Using Trails Scaled Score
Delis-Kaplan Executive Function System (DKEFS),Trail Making Task score was used to assess the cognitive flexibility component of executive function. Scores are derived from time to complete the task plus errors. Wilcoxon rank-sum test was used to examine differences between groups. Normative scores for this assessment range 1-19 (mean of 10, and standard deviation of 3), and a higher score indicates superior cognitive flexibility.
Time frame: During the one day of cognitive assessment administration.
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
Assessment of Cognitive Flexibility Using Color-word Inference Test
DKEFS Color-Word Interference Test (CWIT) Inhibition Switching scores was used to measure the cognitive flexibility component of executive function. The CWIT is scored by time to complete plus errors. Wilcoxon rank-sum test was used to examine differences between groups. Normative scores for this assessment range 1-19 (mean of 10, and standard deviation of 3), and a higher score indicates superior cognitive flexibility.
Time frame: During the one day of cognitive assessment administration.
Assessment of Inhibition Using Color-word Inference Test
DKEFS CWIT scores was used to measure the inhibition component of executive function. The CWIT is scored by time to complete plus errors. Wilcoxon rank-sum test was used to examine differences between groups. Normative scores for this assessment range 1-19 (mean of 10, and standard deviation of 3), and a higher score indicates superior inhibition.
Time frame: During the one day of cognitive assessment administration.
Verbal Ability Cognitive Control Assessed by Letter Fluency
DKEFS Letter Fluency Task will be used to assess the verbal functioning cognitive control ability component of executive function. Scores are derived from the number of unique, correct words. Wilcoxon rank-sum test was used to examine differences between groups. Normative scores for this assessment range 1-19 (mean of 10, and standard deviation of 3), and a higher score indicates superior verbal functioning cognitive control ability.
Time frame: During the one day of cognitive assessment administration.
Assessment of Psychomotor Speed
The grooved pegboard test is a manipulative dexterity task that assesses psychomotor speed, fine motor control, and rapid-visual motor coordination. Participants were asked to insert 25 grooved pegs into holes within the given time limit up to 300 seconds (the score upper limit is thus 300). Time taken to complete the test has been found to be inversely correlated with cognitive ability; therefore, a higher score represents an inferior score. Wilcoxon rank-sum test was used to examine differences between groups.
Time frame: During the one day of cognitive assessment administration.
Verbal Ability Cognitive Control Assessed by Category Fluency
DKEFS Category Fluency scores were used to measure cognitive control of verbal ability, specifically measuring an individuals ability to access and retrieve semantic information (memory) as a component of executive function. Category fluency is scored by number of correct words plus errors in a 60 second trial in each of 3 categories. Wilcoxon rank-sum test was used to examine differences between groups. Normative scores for this assessment range 1-19 (mean of 10, and standard deviation of 3), and a higher score indicates superior cognitive control of verbal ability.
Time frame: During the one day of cognitive assessment administration.
Verbal Ability Cognitive Flexibility, Assessed by Category Switching Scaled Score
DKEFS Category Switching scores will be used to measure cognitive control of verbal ability, specifically measuring an individuals ability to access and retrieve semantic information (memory), switching back and forth between 2 different semantic categories, a component of executive function. Category switching is scored by number of correct words plus errors. Wilcoxon rank-sum test was used to examine differences between groups. Normative scores for this assessment range 1-19 (mean of 10, and standard deviation of 3), and a higher score indicates superior cognitive control of verbal ability.
Time frame: During the one day of cognitive assessment administration.
Verbal Ability Cognitive Control of Inhibition, Assessed by Category Switching Accuracy Scaled Score
DKEFS Category Switching Accuracy scores will be used to measure cognitive control of verbal ability, specifically measuring an individuals ability to inhibit incorrect or repetitive semantic information (memory), while switching back and forth between 2 different semantic categories, a component of executive function. Wilcoxon rank-sum test was used to examine differences between groups. Normative scores for this assessment range 1-19 (mean of 10, and standard deviation of 3), and a higher score indicates superior cognitive control of verbal ability.
Time frame: During the one day of cognitive assessment administration.
Lexical Processing Assessed by Letter Fluency, First Interval.
DKEFS Letter Fluency, first interval scores will be used to measure cognitive control of lexical processing, specifically measuring an individuals ability to retrieve phonemic information, a component of executive function. Participants are asked to name as many words a they are able starting with a specific letter, without repetition. Wilcoxon rank-sum test was used to examine differences between groups. There are four intervals of this task the first assessing initiation of retrieval while the following trials measuring the ability to sustain retrieval. Normative scores for this assessment range 1-19 (mean of 10, and standard deviation of 3), and a higher score indicates superior cognitive control of lexical processing.
Time frame: During one day of cognitive assessement administration.
Lexical Processing as Assessed by Letter Fluency, Second Interval
DKEFS Letter Fluency, second interval scores will be used to measure cognitive control of lexical processing, specifically measuring an individuals ability to retrieve phonemic information, a component of executive function. There are four intervals of this task the second through fourth trial assess ability to sustain retrieval. Participants are asked to name as many words a they are able starting with a specific letter, without repetition. Wilcoxon rank-sum test was used to examine differences between groups. Normative scores for this assessment range 1-19 (mean of 10, and standard deviation of 3), and a higher score indicates superior cognitive control of lexical processing.
Time frame: During one day of cognitive assessement administration.
Lexical Processing Assessed by Letter Fluency, Third Interval
DKEFS Letter Fluency, third interval scores will be used to measure sustainment of cognitive control of lexical processing, specifically measuring an individuals ability to continue to retrieve phonemic information after multiple trials, a component of executive function. There are four intervals of this task the second through fourth trial assess ability to maintain retrieval. Participants are asked to name as many words a they are able starting with a specific letter, without repetition. Wilcoxon rank-sum test was used to examine differences between groups. Normative scores for this assessment range 1-19 (mean of 10, and standard deviation of 3), and a higher score indicates superior sustainment of cognitive control of lexical processing.
Time frame: During one day of cognitive assessment administration.
Lexical Processing Assessed by Letter Fluency, Fourth Interval
DKEFS Letter Fluency, fourth interval scores will be used to measure sustainment of cognitive control of lexical processing, specifically measuring an individuals ability to continue to retrieve phonemic information after multiple trials, a component of executive function. There are four intervals of this task the second through fourth trial assess ability to maintain retrieval. Participants are asked to name as many words a they are able starting with a specific letter, without repetition. Wilcoxon rank-sum test was used to examine differences between groups. Normative scores for this assessment range 1-19 (mean of 10, and standard deviation of 3), and a higher score indicates superior sustainment of cognitive control of lexical processing.
Time frame: During one day of cognitive assessment administration.