Disparate effects of ankle-brachial index on mortality in the 'very old' and 'younger old' populations-the PolSenior survey

To assess the relationship between ankle-brachial index (ABI) and up to 10-year mortality in older individuals below and above the age of 80 years. In a multicenter survey of health status in the community dwelling subjects aged 55-59 and 65 + years in Poland, we assessed baseline medical history including risk-factors. We measured ABI, and serum creatinine, cholesterol, NT-proBNP, and interleukin-6 (IL-6) concentrations. We assessed mortality based on public registry. Between 2009 and 2019, 27.3% of 561 participants < 80 years, and 79.4% of 291 participants >= 80 years, died (p < 0.001); 67.8, 41.5, and 40.3% in the ABI groups < 0.9, 0.9-1.4, and > 1.4, respectively (p < 0.01). In the unadjusted Cox models, ABI was associated with mortality in the entire group, and < 80 years. In the entire group, analysis adjusted for age and sex showed mortality risk increased by 11% per year, and 50% with male sex. Mortality decreased by 37% per 1 unit ABI increase. In the group of people >= 80 years, only age was significantly associated with mortality (p < 0.001). In stepwise regression ABI < 0.9, male sex, active smoking, and NT-proBNP level were associated with risk of death < 80 years. In the >= 80 years old, mortality risk was associated with older age, and higher levels of IL-6, but not ABI. The ABI < 0.9 is associated with higher mortality in older people, but not among the oldest-old. In the oldest age group, age is the strongest predictor of death. In this age group, inflammageing is of importance.

Automated summary

The ankle-brachial index (ABI) is associated with long-term mortality risk in older individuals, particularly when ABI is less than 0.9. In the 80 years and older age group, mortality is mainly influenced by age and IL-6 levels, rather than ABI.