Life satisfaction is associated with the relationship between mild cognitive impairment and the incidence of disability

Abstract

AbstractBackgroundLife satisfaction has been shown to be lower in older adults with a higher risk for dementia. For many years, dementia has been the highest factor in the incidence of disability among older Japanese adults. The relationship between the incidence of disability and cognitive status has already been clarified, but whether life satisfaction is related to this relationship has not yet been clarified. Therefore, the purpose of this study was to clarify whether life satisfaction is related to the relationship between incidence of disability and cognitive status.MethodParticipants comprised 2798 older adults (1579 women; mean age: 73.0 years, SD = 5.9, range 65–96 years) from the National Center for Geriatrics and Gerontology–Study of Geriatric Syndromes. Baseline measurements, including cognitive status (NC, normal cognition; MCI, mild cognitive impairment; GCI, global cognitive impairment), life satisfaction, and demographic characteristics. Life satisfaction was measured using the life satisfaction scale (LSS), ranging from 13 to 52. LSS was stratified into three levels based on the score: lowest, moderate, and highest. Associations between disability incidence and cognitive status were examined for each group according to life satisfaction; monthly assessment for disability was monitored through long‐term care insurance certification for at least 2 years.ResultDuring a mean follow‐up of 35.3 months (SD = 6.0), 193 participants developed a disability. The potential confounding factors adjusted hazard ratios (refer to NC) for incidence of disability in the group with the lowest life satisfaction were 1.83 (CI, 1.03 to 3.26; P = 0.040) and 1.73 (CI, 0.70 to 4.33; P = 0.238) for MCI and GCI, respectively. Similarly, in the group with moderate life satisfaction, MCI and GCI were 2.00 (CI, 1.01 to 3.94; P = 0.046) and 1.90 (CI, 0.57 to 6.28; P = 0.291), respectively. On the other hand, in the group with the highest life satisfaction, MCI and GCI were 1.41 (CI, 0.79 to 2.51; P = 0.245) and 0.96 (CI, 0.36 to 2.55; P = 0.937), respectively.ConclusionMCI was associated with disability incidence, and the effect was more pronounced among older adults who had lower life satisfaction.