title: Dyslipidemia in Achilles tendinopathy is characteristic of insulin resistance.
abstract: Overuse is considered to be a main causative factor for tendinopathies; however, recent reports indicate that tendinopathy is also common among both overweight and inactive individuals. These factors are associated with abdominal obesity, dyslipidemia, hypertension, and insulin resistance. We hypothesized that these features would be associated with tendinopathy.
  
  
  OBJECTIVE
  To compare lipid profile between participants with Achilles tendinopathy and matched controls.
  
  
  METHODS
  Fasting serum lipids were measured among 60 participants with chronic painful midportion Achilles tendinopathy (54% male) and 60 control subjects matched for gender, age (+/-10 yr), and body mass index (+/-2 kg x m(-2)).
  
  
  RESULTS
  The participants with Achilles tendinopathy showed evidence of underlying dyslipidemia. They had higher triglyceride (TG) levels (P = 0.039), lower %HDL-C (P = 0.016), higher TG/HDL-C ratio (P = 0.036), and elevated apolipoprotein B concentration (P = 0.017) in comparison to the well-matched control group.
  
  
  CONCLUSIONS
  This pattern of dyslipidemia is characteristic of the dyslipidemia displayed by individuals with insulin resistance and is common in the metabolic syndrome. Two additional aspects of tendinopathy research support a connection with the metabolic syndrome. First, tendinopathy has been associated with greater waist circumference, as has the metabolic syndrome. Second, insulin resistance has been associated with fat deposition in muscle (primarily intracellular), whereas fat deposition in tendon has been found among those with tendon pain.If tendinopathy is confirmed to be associated with dyslipidemia and the metabolic syndrome in larger studies, it may be appropriate to redefine our concept of tendinopathy to that of a cardiovascular disease (CVD). In this case, we may be able to draw considerably on CVD research to improve our understanding of tendinopathy, and perhaps treating CVD risk factors will improve the treatment of tendinopathy.
authors.affiliation: School of Exercise and Nutrition Sciences, Deakin University, Burwood, Victoria, Australia. jega@deakin.edu.au
authors.forename: James Edmund
authors.initials: JE
authors.lastname: Gaida
authors.forename: Lotta
authors.initials: L
authors.lastname: Alfredson
authors.forename: Zoltan Steven
authors.initials: ZS
authors.lastname: Kiss
authors.forename: Andrew Michael
authors.initials: AM
authors.lastname: Wilson
authors.forename: Håkan
authors.initials: H
authors.lastname: Alfredson
authors.forename: Jill Leigh
authors.initials: JL
authors.lastname: Cook
mesh_terms: D000125:Achilles Tendon / Q000000981:diagnostic imaging / Q000293:injuries*; D000328:Adult; D001786:Blood Glucose; D015992:Body Mass Index; D016022:Case-Control Studies; D050171:Dyslipidemias / Q000503:physiopathology*; D005215:Fasting; D005260:Female; D006801:Humans; D007333:Insulin Resistance; D008055:Lipids / Q000097:blood*; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D052256:Tendinopathy / Q000209:etiology* / Q000503:physiopathology; D018608:Ultrasonography, Doppler
chemical_list: D001786:Blood Glucose; D008055:Lipids