Genetic Influences Between Cognitive Function and BMI

Shared Genetic Influences Between Cognitive Function and Body Mass Index (BMI) in the Texas Twin Project

In this study the investigators will interrogate an existing data set to examine whether genetic variants contribute to an inverse association between weight status and cognitive function. Investigators hypothesize that body mass index (BMI) will be inversely related to a number of variables measuring cognitive function, and that that this inverse relation will be at least partially attributable to genetic variants which influence both BMI and cognition.

Study Overview

• Status: Completed
• Conditions: Obesity

Detailed Description

Investigators will use existing data collected as part of the Texas Twin Project (TTP). TTP collected neuropsychological task data on cognition (executive functioning and general cognitive abilities) from a computerized test battery, as well as BMI data, on a sample of 869 twins. Investigators will use information from the known extent of genetic and environmental sharing between members of MZ (monozygotic; identical) and DZ (dizygotic; fraternal) twin pairs to quantify the genetic correlation between measures of cognition and BMI using biometric genetic modeling under the assumptions of the classical twin model. The specific aims are:

• To examine the association between BMI and executive functioning (EF) in a sample of 869 twin children, ages 7 to 15 years old, who participated in the Texas Twin Project (TTP)
• To gauge the specificity of EF-BMI relations relative to academic achievement and general cognitive abilities.
• To examine the relative contribution of genetic and environment influences to the inverse association between BMI and EF

• Study Type: Observational
• Enrollment (Actual): 869

Contacts and Locations

Study Locations

• United States
  • Texas
    • Houston, Texas, United States, 77030
      • Children's Nutrition Research Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 7 years to 15 years (Child)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Individuals from the Texas twin Project dataset, who were twins and higher-order multiples previously recruited from the Houston and Austin Metropolitan areas, via flyers, the internet (study website) and contact through public school rosters

Description

Inclusion Criteria:

All participants in the TTP database with executive functioning and BMI data, without a parent-reported medical disorder affecting growth

Exclusion Criteria:

Parent-reported medical disorder affecting growth More than one sibling in the dataset (if triplets are present, only two randomly selecting siblings will be included).

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Executive functioning	This measure will be derived from a computerized test battery incorporating the Animal Stroop, Stop Signal, Mickey (an anti- Trail Making, Local-Global, Plus-Minus, Digit Span Backward, Symmetry Span, Listening Recall, 2-Back, Keeping Track, and Running Memory for Letters tasks. A latent factor of variance common to all these tasks will be used to indicate "higher order executive functioning".	2 hours
Body mass index	Heights and weights were measured by trained study personnel and BMI will be calculated as weight in kilograms (kg) divided by height in centimeters (cm) squared.	10 minutes

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
General Cognitive Ability	This was assessed using the WASI-II	1 hour
Academic Achievement	This was assessed using the Woodcock-Johnson-III Calculations and Passage Comprehension tests	30 minutes

Collaborators and Investigators

• Sponsor: Baylor College of Medicine

Study record dates

Study Major Dates

• Study Start (Actual): September 1, 2009
• Primary Completion (Actual): December 1, 2016
• Study Completion (Actual): December 1, 2016

Study Registration Dates

• First Submitted: April 12, 2017
• First Submitted That Met QC Criteria: April 12, 2017
• First Posted (Actual): April 17, 2017

Study Record Updates

• Last Update Posted (Actual): April 18, 2017
• Last Update Submitted That Met QC Criteria: April 14, 2017
• Last Verified: April 1, 2017

More Information

Terms related to this study

• Keywords: Obesity; cognition; BMI; executive functioning; heritability; general cognitive ability; twin study; GCTA
• Additional Relevant MeSH Terms: Overnutrition; Nutrition Disorders; Overweight; Body Weight; Obesity
• Other Study ID Numbers: H-37801

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: This protocol involves secondary data analysis of existing studies. Data will not be shared with other investigators since they should obtain data from the primary sources.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No