Bridging the age gap: improving representation of older adults in clinical trials for type 2 diabetes and chronic kidney disease

Chronic kidney disease (CKD) is common among older adults, with more than a third of individuals older than 65 years having moderate to severe CKD globally. Management of CKD in older adults is often complex because of multiple comorbidities, polypharmacy, and frailty. However, older adults remain under-represented in clinical trials for both type 2 diabetes (T2D), which is the leading risk factor for CKD, and CKD itself. Recent analyses show consistent low representation of older adults in T2D trials. Similarly, participants of dialysis trials tend to be younger, healthier, and have a lower mortality rate than individuals in the real-world dialysis population, and even greater age disparities are reported in trials for non-dialysis-dependent CKD. This under-representation limits the evidence base for treating older adults and often compels clinicians to extrapolate findings from younger populations or rely on observational data. Consequently, both undertreatment and overtreatment of T2D and CKD might occur. Excluding older adults from trial participation leads to society bearing the costs of avoidable harms from preventable adverse events, inappropriate medication use, and missed opportunities to improve functional outcomes in an ageing population. Addressing this age gap in trial population and target treatment population is crucial to ensure evidence-based, equitable care for older adults. In this Personal View, we explore the barriers of under-representation of older adults and propose strategies to enhance their inclusion in future trials for T2D and CKD.