Inflammatory biomarkers and physical function in older, obese adults with knee pain and self-reported osteoarthritis after intensive weight-loss therapy

J Am Geriatr Soc. 2008 Apr;56(4):644-51. doi: 10.1111/j.1532-5415.2007.01636.x. Epub 2008 Feb 28.


Objectives: To describe the relationships between proinflammatory biomarkers and self-reported and performance-based physical function and to examine the effect of weight loss on these markers of inflammation.

Design: Randomized, longitudinal, clinical study comparing subjects eating an energy-restricted diet and participating in exercise training with a control group.

Setting: Community-base participants for the Physical Activity, Inflammation and Body Composition Trial.

Participants: Eighty-seven obese (body mass index (BMI) >30.0 kg/m(2)) adults aged 60 and older with knee pain and self-report of osteoarthritis.

Measurements: Inflammatory biomarkers (interleukin 6 (IL-6), tumor necrosis factor alpha (TNFalpha), C-reactive protein, and soluble receptors for TNFalpha (sTNFR1 and sTNFR2)) and self-reported (Western Ontario and McMaster University Osteoarthritis Index questionnaire) and performance-based (6-minute walk distance and stair climb time) measures of physical function at baseline and 6 months.

Results: Mean (standard error of the mean) weight loss was 8.7% (0.8%) in the intervention group, compared with 0.0% (0.7%) in the control group. sTNFR1 was significantly less in the intervention group than in the control group at 6 months. sTNFR1 and sTNFR2 predicted stair climb time at baseline. Change across the 6-month intervention for sTNFR2 was an independent predictor for change in 6-minute walk distance.

Conclusion: These results indicate that an intensive weight-loss intervention in older obese adults with knee pain can help improve inflammatory biomarkers and that changes in these concentrations showed associations with physical function.

Publication types

  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Arthralgia / etiology*
  • Arthralgia / physiopathology
  • Arthralgia / rehabilitation
  • Biomarkers / blood
  • Body Mass Index
  • C-Reactive Protein / metabolism*
  • Cytokines / blood*
  • Enzyme-Linked Immunosorbent Assay
  • Exercise Therapy / methods
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Middle Aged
  • Motor Activity / physiology*
  • Obesity / blood*
  • Obesity / complications
  • Obesity / physiopathology
  • Osteoarthritis, Knee / blood
  • Osteoarthritis, Knee / complications*
  • Osteoarthritis, Knee / physiopathology
  • Pain Measurement
  • Prognosis
  • Severity of Illness Index
  • Surveys and Questionnaires
  • Weight Loss / physiology*


  • Biomarkers
  • Cytokines
  • C-Reactive Protein