Age-related changes in physical and psychological functions among community-dwelling middle-aged and older adults: A cross-sectional study

Objectives As the number of older workers increase, the proportion of occupational accidents among them has increased. To prevent such accidents, it is crucial to understand the characteristics of age-related decline in physical and psychological function from middle to old age. This study aimed to elucidate these characteristics and discuss occupational health issues in middle to old age.Methods This study was part of the National Institute for Longevity Sciences - Longitudinal Study of Aging, involving 1,153 men and 1,117 women Japanese community-dwelling participants aged 40-84 years during the seventh wave (2010-2012). Hearing function, visual function, postural balance, motor fitness, gait function, cognitive function, mental health, and bone mineral density were measured using a survey. Descriptive statistics and z-scores (based on the age groups; 40-44, 45-54, 55-64, 65-74, and 75-84) were calculated based on sex and age group. Statistical significance was set at P < 0.05 (z-score; ≥ ±1.96).Results Compared to those aged 40-44 years, those aged 75-84 showed significantly lower z-scores for hearing function (z-score for air-conduction pure-tone threshold at 8,000 Hz; +4.78 for men, +4.91 for women), near visual acuity (+4.42 for men), information processing ability (-3.94 for women), and muscular endurance (z-score for upper body raising; -2.73 for men, -2.38 for women). Conversely, age differences were relatively small (-0.5 < z-score < 0.5 in all ages) in gait pace, depression scores, and life satisfaction in both sexes.Conclusion Hearing function (especially at high frequencies) scores were significantly lower in older age groups, followed by near visual acuity, information processing ability, and muscular endurance in both sexes. However, there were no clear age-related differences in the gait pace, psychological health, or life satisfaction. Occupational health check-ups must be implemented based on an understanding of the characteristics of changes in physical and psychological functions with aging.