How combinations of chronic diseases influence frailty progression in older adults
Many older adults live with multiple chronic diseases. This is often described as multimorbidity, usually defined as having two or more chronic conditions.
But the number of diseases alone may not fully explain how health declines with age. A study using LifeLines cohort data investigated whether specific combinations of diseases influence how frailty develops and how health changes over time in older adults.
Looking beyond the number of diseases
Most research measures multimorbidity by simply counting the number of chronic diseases. However, different diseases often occur together in recognizable patterns.
In this study, researchers identified multimorbidity configurations—groups of chronic conditions that tend to co-occur—and examined whether these configurations are linked to different frailty trajectories and mortality risks.
Using Lifelines data to study ageing
The study analysed 14,511 Lifelines participants aged 60 years and older.
Researchers followed participants over several years and examined:
- transitions between frailty states (robust, pre-frail, frail)
- changes in frailty levels over time
- mortality risk
Frailty was measured using a 32-item frailty index, which captures health deficits across multiple physiological systems.
Disease combinations influence frailty trajectories
The study found that different disease configurations were associated with distinct frailty patterns.
In particular:
- Cardiovascular-related configurations, such as Heart & Vascular and CVD & Vascular, were linked to less favourable frailty transitions and higher mortality risk.
- Participants in these groups were more likely to experience worsening frailty and had lower chances of recovery compared with individuals without multimorbidity.
By contrast:
- Vascular and metabolic configurations generally showed lower frailty levels than the higher-risk cardiovascular groups, although patterns of recovery differed between configurations.
The Complex Treatment configuration showed the highest frailty levels at baseline, although transitions in this group were difficult to estimate due to the small number of participants and their already high frailty levels.
Why disease patterns matter
The results suggest that the composition of multimorbidity matters, not only the number of chronic conditions.
People with a similar number of diseases may still have different health trajectories, depending on which diseases occur together.
Understanding these patterns can help researchers better identify risk profiles for frailty progression and mortality in ageing populations.
What this means for researchers using Lifelines
This study illustrates how LifeLines data can be used to study complex ageing processes, such as the interaction between chronic diseases and frailty.
By analysing disease patterns rather than disease counts, researchers can gain more detailed insight into:
- how frailty develops
- which groups may be at higher risk of health decline
- how multimorbidity shapes ageing trajectories
These insights may support future research on frailty prevention and healthy ageing.