Age-related deficit accumulation and the diseases of ageing.

With ageing, the potency of individual risk factors traditionally associated with common illnesses declines. Instead, it is becoming clear that the impact of a wide range of age-related deficits not traditionally considered as risk factors for these illnesses increases. These age-related deficits chiefly confer risk as a group, not individually. The many effects of age-related changes can be demonstrated epidemiologically, and in preclinical models, using a frailty index to distinguish between the contributions of traditional and non-traditional risk factors. Quantifying the contribution of age-related deficit accumulation in clinical and preclinical samples offers a powerful new tool for understanding mechanisms of age-related disease. It appears that a range of common late-life illnesses might be targeted by drugs aimed at ageing processes.