Physical and Cognitive Function - Look AHEAD Ancillary Study

A 400 m walk was administered to assess endurance. Participants were instructed to walk at their usual pace and time to complete the 400-m walk was recorded. The 400-m walk test was terminated if the participant reported chest pain, tightness or pressure, significant shortness of breath or difficulty breathing, feeling faint, lightheaded or dizzy, or other pain (e.g., leg pain).Assessed 8 or 9 years post-randomization in Look AHEAD parent Study

Grip strength (kg) was measured twice in each hand using an isometric Hydraulic Hand Dynamometer (Jamar, Bolingbrook, IL). The maximum of the force from two trials for the stronger hand was used in the analyses. Participants with severe hand pain or recent surgery in both hands were excluded from testing. Assessed 8 or 9 years post-randomization in Look AHEAD parent Study.

Maximum knee extensor strength (one repetition maximum (1RM)) was assessed on a Nautilus One™ Leg Extension machine. Participants with prior knee surgery on both knees where all or part of the joint was replaced were excluded from testing. The right leg was tested unless there was a contraindication (e.g., prior knee surgery). If participants experienced knee pain during the test and there were no contraindications to test the other leg, the other leg was tested; if participants experienced knee pain on the other leg, the test was terminated. Assessed 8 or 9 years post-randomization in Look AHEAD parent Study

Trail Making Tests A and B was used to assess attention and concentration (Part A) and executive function (Part B). Part A measures the time (in seconds) to draw lines to connect circled numbers in a numerical sequence and Part B measures the time (in seconds) to draw lines to connect circled numbers and letters in an alternating numeric and alphabetic sequence as rapidly as possible. The difference (in seconds; greater time indicates worse performance) in performance on Part B minus Part A was used in analysis to represent the contrast between performance on the simple (Part A) and alternating conditions (Part B). Assessed 8 or 9 years post-randomization in Look AHEAD parent Study.

The Digit Symbol Substitution Test (DSST) was used to assess working memory. Participants were presented with a legend at the top of the page showing the boxes each with a number from 1 to 9 and below each numbered box is a unique symbol. As rapidly as possible, the participant fills in the randomly ordered boxes with numbers paired with blank boxes with the symbol that corresponds to the number in the legend. The score is the total number of correctly entered symbols completed in 90 seconds (range, 0-133; higher score indicates better performance). Assessed 8 or 9 years post-randomization in Look AHEAD parent Study.

The Rey Auditory Verbal Learning Test (RAVLT) was used to assess verbal memory. The participant is read a list of 15 words five times. After each time the list is given, the participant is asked to immediately recall as many words as possible. Following the fifth recall, an interference list is presented, after which the participant is asked to spontaneously recall words from the original list. After a 10-minute interval has passed, the participant is asked again to recall as many words as possible from the original list. The number of words correctly recalled on the delayed recall were used in the analysis (range, 0-15; higher number correct indicates better performance). Assessed 8 or 9 years post-randomization in Look AHEAD parent Study.

The Modified Stroop Color and Word Test was used to assess executive function. The test measures a participant's ability to view complex visual stimuli and to respond to one stimulus dimension while suppressing response to another competitive stimulation. The participant first reads aloud words denoting colors printed in black ink (Subtest 1), then names aloud the color of blocks printed in colored ink (Subtest 2), and finally names aloud the color ink in which the words are printed in which are incongruent to the word (Subtest 3). The amount of time to complete each subtest and the number of errors are recorded and interference calculated as time to complete Subtest 3 - Subtest 1 + errors (lower interference scores indicate better cognitive performance). Assessed 8 or 9 years post-randomization in Look AHEAD parent Study.

The Modified Mini-Mental Status Exam (3MS) was used to assess global cognitive function. Scores range from 0 to 100 with higher scores indicating better cognitive function. Assessed 8 or 9 years post-randomization in Look AHEAD parent Study.