Key result
Low-normal ABI linked to ~7% lower post-exercise phosphocreatine recovery rate constant vs higher ABI.
Why the study?
Lower muscle mitochondrial energy production may contribute to impaired walking endurance in patients with peripheral arterial disease, and the association of lower ABI within the normal range with mitochondrial energy production is unclear.
Is a low-normal ankle-brachial index (0.90-1.10) associated with lower muscle mitochondrial energy production compared to higher ABI (1.11-1.40) in older adults?
Cross-Sectional (n=363)
Is a low-normal ankle-brachial index (0.90-1.10) associated with lower muscle mitochondrial energy production compared to higher ABI (1.11-1.40) in older adults?
Absolute Event Rate: 19.3% vs 20.8%
p-value: p=0.015
Even within the clinically accepted normal range, a lower ABI (0.90-1.10) is associated with impaired muscle mitochondrial energy production, potentially explaining functional decline.
Borderline ABI may flag subclinical mitochondrial impairment; extends endurance observations but leaves open causal links and intervention targets.
Background Lower muscle mitochondrial energy production may contribute to impaired walking endurance in patients with peripheral arterial disease. A borderline ankle‐brachial index (ABI) of 0.91 to 1.10 is associated with poorer walking endurance compared with higher ABI . We hypothesized that in the absence of peripheral arterial disease, lower ABI is associated with lower mitochondrial energy production. Methods and Results We examined 363 men and women participating in the Baltimore Longitudinal Study of Aging with an ABI between 0.90 and 1.40. Muscle mitochondrial energy production was assessed by post‐exercise phosphocreatine recovery rate constant ( k PC r) measured by phosphorus magnetic resonance spectroscopy of the left thigh. A lower post‐exercise phosphocreatine recovery rate constant reflects decreased mitochondria energy production.The mean age of the participants was 71±12 years. A total of 18.4% had diabetes mellitus and 4% were current and 40% were former smokers. Compared with participants with an ABI of 1.11 to 1.40, those with an ABI of 0.90 to 1.10 had significantly lower post‐exercise phosphocreatine recovery rate constant (19.3 versus 20.8 ms −1 , P =0.015). This difference remained significant after adjusting for age, sex, race, smoking status, diabetes mellitus, body mass index, and cholesterol levels ( P =0.028). Similarly, post‐exercise phosphocreatine recovery rate constant was linearly associated with ABI as a continuous variable, both in the ABI ranges of 0.90 to 1.40 (standardized coefficient=0.15, P =0.003) and 1.1 to 1.4 (standardized coefficient=0.12, P =0.0405). Conclusions An ABI of 0.90 to 1.10 is associated with lower mitochondrial energy production compared with an ABI of 1.11 to 1.40. These data demonstrate adverse associations of lower ABI values with impaired mitochondrial activity even within the range of a clinically accepted definition of a normal ABI . Further study is needed to determine whether interventions in persons with ABIs of 0.90 to 1.10 can prevent subsequent functional decline.
No takes yet. Share an insight, caveat, or question.
AlGhatrif et al. (2017) conducted a cross-sectional in Low-Normal Ankle-Brachial Index (n=363). Ankle-brachial index of 0.90 to 1.10 vs. Ankle-brachial index of 1.11 to 1.40 was evaluated on Post-exercise phosphocreatine recovery rate constant (kPCr) (p=0.015). An ankle-brachial index of 0.90 to 1.10 was associated with a lower post-exercise phosphocreatine recovery rate constant compared with an ABI of 1.11 to 1.40 (19.3 vs 20.8 ms-1, P=0.015).
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: