Compression and Expansion of Morbidity

Specific contribution of cognitive and motor impairments with functional capacity and dependence in Huntington's disease

BACKGROUND

Huntington's disease (HD) leads to increasing dependence. Unlike psychiatric disorders, motor and cognitive deficits evolve progressively over time. Understanding their specific impact on daily activities is crucial for preserving autonomy. However, because cognitive tasks in HD rely on motor functions, and motor tasks demand cognitive processing, disentangling their specific impact remains a challenge.

OBJECTIVE

To identify the specific contribution of cognitive and motor impairments on global functional capacity, basic and instrumental activities of daily living (ADL/IADL), and work-related activities (WRA) in HD.

METHODS

158 HD mutation carriers, enrolled in the BioHD (NCT01412125) and RepairHD (NCT03119246) studies, were evaluated with the Unified Huntington's Disease Rating Scale and the SelfCog. The SelfCog assesses motor processing separately from memory, language, executive functions and visuospatial processing. Linear regressions were fitted to assess how functional capacity declined with motor and cognition impairments. Odds of dependence in ADLs, IADLs and WRAs were estimated using logistic regressions.

RESULTS

Cognitive and motor performance were independently associated with functional capacities, though motor performance showed a stronger association than cognitive performance. Decline of all SelfCog cognitive domains contributed to functional decline, with stronger association with global and executive scores compared to language, visuospatial, and memory domains. Higher global and executive deficits were associated with an increased risk of dependence in ADLs, IADLs, and WRAs.

CONCLUSION

The independent contributions of motor, followed by cognitive-mainly executive-functions to functional decline suggest targeted interventions to preserve autonomy and quality of life in HD.

Effects of population aging on quality of life and disease burden: a population-based study

BACKGROUND

As population aging intensifies, it becomes increasingly important to elucidate the casual relationship between aging and changes in population health. Therefore, our study proposed to develop a systematic attribution framework to comprehensively evaluate the health impacts of population aging.

METHODS

We used health-adjusted life expectancy (HALE) to measure quality of life and disability-adjusted life years (DALY) to quantify the burden of disease for the population of Guangzhou. The HALE and DALY projections were generated using both the Bayesian age-period-cohort models and the population prediction models. Changes in HALE and DALY between 2010-2020 and 2020-2030 were decomposed to isolate the effects of population aging. Three scenarios were analyzed  to examine the relative relationship between disease burden and population aging. In Scenarios 1 and 2, the disease burden rates in 2030 were assumed to  either remain at 2020 levels or follow historical trends. In Scenario 3, it was assumed that the absolute numbers of years of life lost (YLL) and years lived with disability (YLD) in 2030 would remain unchanged from the 2020 levels.

RESULTS

Between 2010 and 2020, 56.24% [69.73%] of the increase in male [female, values in brackets] HALE was attributable to the mortality effects in the population aged 60 and over, while - 3.74% [- 9.29%] was attributable to the disability effects. The increase in DALY caused by changes in age structure accounted for 72.01% [46.68%] of the total increase in DALY. From 2020 to 2030, 61.43% [69.05%] of the increase in HALE is projected to result from the mortality effects in the population aged 60 and over, while - 3.88% [4.73%] will be attributable to the disability effects. The increase in DALY due to changes in age structure is expected to account for 102.93% [100.99%] of the total increase in DALY. In Scenario 1, YLL are projected to increase by 45.0% [54.7%], and YLD by 31.8% [33.8%], compared to 2020. In Scenario 2, YLL in 2030 is expected to decrease by - 2.9% [- 1.3%], while YLD will increase by 12.7% [14.7%] compared to 2020. In Scenario 3, the expected YLL rates and YLD rates in 2030 would need to be reduced by 15.3% [15.4%] and 15.4% [15.6%], respectively, compared to 2020.

CONCLUSIONS

The disability effects among the elderly population hinder improvements in quality of life, while changes in age structure are the primary driver of disease burden accumulation. To mitigate the excess disease burden caused by population aging, it is essential to achieve a reduction of more than 15% in the disease burden by 2030 compared to 2020. Our proposed attribution framework evaluates the health impacts of population aging across two dimensions: quality of life and disease burden. This framework enables comparisons of these effects over time and across different regions.

[How has life expectancy without functional limitations developed in Germany? An analysis with data from the German Ageing Survey (DEAS)]

INTRODUCTION

The long-term increase in life expectancy raises the question of whether the increased life expectancy is accompanied by an extension of years without health limitations. The study analyzes how life expectancy without functional and mobility limitations from the ages of 46 and 65 and their proportions of remaining life expectancy have changed since 2008.

METHODS

We analyze data from the German Ageing Survey of the 2008, 2014, and 2020/21 waves. Life expectancy without functional limitations (disability-free life expectancy-DFLE) was calculated using the Sullivan method. Severe functional limitations (using the Global Activity Limitation Indicator-GALI) and mobility limitations (climbing stairs, walking more than 1 km) were examined.

RESULTS

Compression of morbidity in the GALI has been observed in 46- and 65-year-old men since 2014, but not in women of the same age. In terms of mobility, 46- and 65-year-old men show trends towards compression when climbing stairs and 46-year-old men when walking more than 1 km since 2014. The values for women have stagnated for the first two indicators mentioned, but not for 46-year-old women since 2014 when walking more than 1 km.

DISCUSSION

Our analyses show different trends in DFLE depending on the indicator, age, and gender and do not allow a clear answer to the question of morbidity compression or expansion. We tend to see morbidity compression in men, whereas trends of stagnation or expansion tend to be seen in women. These results signal challenges in maintaining functional health, especially in women, and point to the need for targeted interventions to improve quality of life and healthy life expectancy.

Trends in severe functional limitations among working and non-working adults in Germany: Towards an (un)-healthy working life?

We examined trends in severe functional limitations among working and non-working adults in Germany (ages 40-65). Four population-based samples of 11,615 participants were used, spanning the time periods 2002-2021. The overall prevalence of severe limitations was found to be 12.8% in the sample, but also varied from 10 to 20% according to occupational group. Over time, severe limitations were found to have increased, from 10.6% in 2002 to 13.2% in 2021. Logistic regression analysis showed that severe limitations increased significantly in certain subgroups, including working women with a low skilled white collar occupational group, working men with a low skilled blue collar occupational group and, particularly, among the whole non-working population, whereas limitations remained largely the same in the other groups, including most of the working population. In terms of expectancies, overall working life expectancy increased. Along with this increase, healthy (non-severely limited) working life expectancy increased, but this trend was accompanied by a clear increase in unhealthy working life expectancy (severely limited). Thus, although severe limitations have increased in some groups in the working-age adults, people today can expect to work more years free from severe limitations than before. In the future, potentials to increase working life expectancy may come to an end, as severe limitations increased strongly in the non-working population, which could limit the prospects for a further increase in the proportion of the population in employment. Further studies are needed to investigate the potential impact of the increasing prevalence of severe limitations on the population's ability to work.