Metabolic Risk Factors Relate to Worse Tendon Health in Individuals With Achilles Tendinopathy

A high proportion of individuals with Achilles tendinopathy continue to demonstrate long-term symptoms and functional impairments after exercise treatment. Thus, there is a need to delineate patient presentations that may require alternative treatment. The objective of this study was to evaluate if the presence of metabolic risk factors relates to tendon symptoms, psychological factors, triceps surae structure, and lower limb function in individuals with Achilles tendinopathy. One hundred and fifty-eight individuals (88 female) with diagnosed midportion Achilles tendinopathy were divided into three groups based on the number of metabolic risk factors linked to cardiovascular disease present at baseline: two or more factors, one factor, no factors. Metabolic risk factors were determined by clinical evaluation and past medical history. Achilles tendinopathy symptoms (Victorian Institute of Sport Assessment-Achilles, Patient Reported Outcome Measurement Information System, movement-evoked pain ratings), psychological factors (Tampa Scale for Kinesiophobia), triceps surae structure (B-mode ultrasound of tendon and muscle morphology, continuous shear wave elastography of tendon mechanical properties), and lower limb function (test battery) were compared among groups. Individuals with two or more metabolic risk factors had worse symptoms with loading (p = 0.011), smaller Achilles tendon size relative to body mass (p = 0.002), and worse lower limb function compared to individuals without metabolic risk factors (p < 0.02). No differences were observed between individuals with one metabolic risk factor and those without metabolic risk factors. Future consideration of multiple metabolic risk factors for individuals with Achilles tendinopathy could facilitate understanding the underlying impairments of tendon pathology and recovery that may be addressed with treatment.