Relationships Among Cognitive Function and Handgrip Strength And Endurance In Older Men And Women

Abstract

PURPOSE: To examine the relationships among cognitive function and handgrip strength and endurance in older adults. METHODS: Seventy-one healthy older adults (22 men, 49 women) ages 65-85 years (mean±SD height=168±8 cm, mass=76±14 kg) participated. After familiarization, participants were tested for cognitive function: serial sevens (S7), trail making (TM), and Rey Auditory Verbal Learning Test (RAVLT). The S7 test was timed to completion (S7T) and number of errors (S7E) while counting backwards from 100 by sevens. The TM test timed participants drawing lines sequentially connecting encircled numbers and letters using two patterns: A (TMA) and B (TMB). The RAVLT scored five 15-item auditory word recalls (RSUM), an interference word recall (RB), a 6th word recall (R6), and a 15-item visual word recognition trial (RR). After maximal handgrip strength measurements (HGMAX, Jamar ®, Warrenville, IL), intermittent handgrip contractions at 50% of HGMAX were performed until failure, and the number of contractions was recorded as handgrip endurance (HGCON). Independent samples t-tests (or Mann-Whitney U) for gender differences and Pearson r (or Spearman’s ρ) for correlations analyzed the normally (or non-normally) distributed variables. RESULTS: Men were taller and heavier (p≤0.05), but there was no gender difference in age (p>0.05). Women scored better (p≤0.05) than men for RSUM, R6, and RR, while men had greater handgrip strength (p<0.01). For women, HGCON was related to RSUM (ρ=0.30, p=0.04) and R6 (ρ=0.36, p=0.01). For men, HGMAX was correlated with R6 (ρ=0.49, p=0.02). CONCLUSIONS: Handgrip endurance (HGCON) was positively related to word recall scores for women, but not men. Conversely, handgrip strength (HGMAX) was positively related to one word recall score (R6) for men, but not for women. These findings suggested that any relationships among cognitive function and handgrip strength and/or endurance may be gender-specific in healthy adults.