Frailty is considered a multidimensional geriatric syndrome, manifested by the accumulation of age-associated deficits. The consequences of frailty transitions are still understudied. This study evaluated the influence of frailty transitions on cognitive function in the older adult population. We used data derived from the Korean Longitudinal Study of Aging (KLoSA) (2008–2018) on older adults aged ≥ 65 years. Frailty was assessed using a validated Korean frailty measure known as the frailty instrument (FI), and cognitive function was measured using the Korean version of the Mini-Mental State Examination (K-MMSE). Transitions in frailty and their relationship with cognitive function were investigated using lagged generalized estimating equations (GEE), t-tests, and ANOVA. Respondents who experienced frailty transitions (those with ameliorating frailty), those who developed frailty, and whose frailty remained constant, were more likely to have a lower cognitive function than those who were consistently non-frail. Older age, activities of daily living (ADL) disability, and instrumental ADL disability were more negatively associated with declining cognitive function, especially in the “frail → frail” group. Changes in all individual components of the frailty instrument were significantly associated with impaired cognitive function. The results suggest an association between frailty transitions and cognitive impairment. Over a 2-year span, the remaining frail individuals had the highest rate of cognitive decline in men, while the change from non-frail to frail state in women was significantly associated with the lowest cognitive function values. We recommend early interventions and prevention strategies in older adults to help ameliorate or slow down both frailty and cognitive function decline.

Background: The effect of noise and vibration exposure on disturbed sleep has been investigated in the past. However, this study was carried out to investigate the relationship between workplace noise and vibration exposure with insomnia amongst representative Korean workers, both simultaneously and separately. Methods: Our research analyzed an overall population of 30,837 workers aged 15 years or older using data derived from the 5th Korean Working Conditions Survey (KWCS) conducted in 2017. Chi-squared tests and logistic regression were performed to investigate baseline characteristics and to quantify the association between workplace exposure to noise and vibration with insomnia. Relative excess risk due to interaction (RERI), attributable proportion (AP), and synergy index (S) were calculated to measure interactions between simultaneous noise and vibration exposure with insomnia. Results: The prevalence of those who reported insomnia was 18.3% of the general population. Among men and women, insomnia in those who were exposed to noise only was 13.9% and 18.3%, respectively, and in those who were exposed to vibration only, it was 23.9% in males and 26.4% in females. Insomnia in those who were exposed to both noise and vibration simultaneously was 20.5% and 41.2% in men and women, respectively. The odds ratio (OR) of insomnia due to noise exposure was 1.10 and 1.07 in men and women, respectively. OR of vibration exposure was 1.84 in men and 1.58 in women. For noise plus vibration exposure OR was 1.83 in men and 3.14 in female workers, where the synergistic effect of noise and vibration exposure could be seen. The association between the varying degree of simultaneous noise plus vibration exposure with insomnia showed a dose–response relationship. The interaction measures showed a synergistic effect of simultaneous exposure in women but not in men. Conclusion: Our study revealed an association between occupational noise and vibration exposure and insomnia, both individually and simultaneously. Additional studies and research are required to further comprehend this relationship.

Background The importance of SA (Successful aging) has been emphasized in recent years, with focus shifting towards attaining healthier aging rather than longevity. However, the influence of SA and its changes on mental health such as depression remains a relatively unexplored area in gerontology. Therefore, we investigated the longitudinal association between changes in SA and depressive symptoms in Korean older adults. Methods This study comprised a longitudinal sample of older adults aged ≥ 45 years, drawn from the Korean Longitudinal Study of Aging (2006–2018). Changes in SA status was determined using the Rowe and Kahn model over two consecutive years. Using an adjusted generalized estimating equation model, we examined the association between changes in successful aging status, namely SA and NSA (Non-successful aging), and depressive symptoms. Results Compared to the SA→SA group, depressive symptom risk in the NSA→NSA and SA→NSA groups were higher in men [(OR, 1.16; 95 % CI, 1.13–1.18), (OR, 1.11; 95 % CI, 1.08–1.13), respectively] and in women [(OR, 1.15; 95 % CI, 1.13–1.18), (OR, 1.11; 95 % CI, 1.09–1.14), respectively]. Subgroup analysis of the dimensions of successful aging revealed that low or worsening criteria of successful aging status in men and women were associated with depressive symptoms. Conclusions Korean older adults who continuously failed to attain or maintain successful aging status had the highest risk of depressive symptoms. These results could further assist in establishing policies and interventions that promote successful aging and subsequently protect the mental health of the Korean older adult population.

In this study, we aimed to examine the association between tinnitus and depressive symptoms in middle-aged and elderly South Korean population. The participants were selected from among those who participated in the 2014, 2016, and 2018 Korea National Health and Nutrition Examination Surveys. The incidence and severity of tinnitus was assessed using a self-reported questionnaire, while depressive symptoms were evaluated using self-reported Patient Health Questionnaire-9. Multiple logistic regression was performed to examine the association between tinnitus and depressive symptoms. Overall, 10 979 (4821 men and 6158 women) participants were enrolled in the study. Regardless of sex, individuals who reported having tinnitus were more likely to have depressive symptoms than those without tinnitus (men: odds ratio 1.53, 95% confidence interval 1.01–2.32; women: odds ratio 1.78, 95% confidence interval 1.35–2.35). In severe cases of tinnitus, women were more likely to have depressive symptoms (odds ratio 7.18, 95% confidence interval 3.71–13.87) compared to men. This study revealed a significant association between tinnitus and depressive symptoms among the middle-aged and elderly South Korean population.