Obesity alone does not cause knee osteoarthritis
September 29th, 2009 - 5:11 pm ICT by ANIWashington, Sep 29 (ANI): In a study on mice, Duke University researchers have found that obesity alone cannot lead to osteoarthritis, a progressive musculoskeletal disorder that is characterized by loss of joint cartilage.
The researchers studied leptin-deficient mice to determine the role of obesity in developing knee osteoarthritis (OA).
In their opinion, obesity caused by a leptin deficiency would result in a higher incidence of knee OA.
Mice with a disruption of leptin signalling showed a 3-fold increase in body mass and 10-fold increase in body fat, but surprisingly did not display effects of knee OA.
The researchers compared leptin-deficient and leptin receptor-deficient female mice with wild-type mice to further understand the role this deficiency may play in increasing risk of knee OA.
At 10-12 months of age, mice were measured for body fat content and blood samples were taken to determine the level of inflammation in the animals.
Knee joints were analysed to determine bone thickness and to look for degenerative changes in the lateral femur, lateral tibia, medial femur, and medial tibia.
Though higher levels of leptin are present in obese individuals, they apparently have a resistance to the effects of the hormone where the body does not receive the signal it is full after eating.
According to Dr. Farshid Guilak and colleagues, the leptin-deficient mice showed a 10-fold increase in adiposity (body fat) but not a higher incidence of OA compared with wild-type mice.
“It was surprising that knee OA was not present given the severity of obesity in the leptin-impaired mice,” said Guilak.
The study implies that leptin could be directly involved in OA because without that hormone, obesity did not influence the occurrence of OA in the mice.
Mice with loss of leptin function also had reduced bone thickness beneath the cartilage and increased tissue volume at the end of the tibia, suggesting that obesity, other obesity-dependent factors, or the absence of leptin signalling independently diminishes bone structure.
The findings of the study have been published in Arthritis and Rheumatism. (ANI)
- Site in brain where leptin may trigger puberty identified - Dec 23, 2010
- New discovery opens way to fat busting pill - Mar 08, 2011
- New discovery paves way for anti-obesity pill - Mar 08, 2011
- Found! Hormone that makes you pile on pounds - Oct 16, 2011
- Existing osteoporosis drug may keep joint injuries from causing long-term osteoarthritis - Sep 13, 2009
- How the brain may fail to tell the body 'it is full' after a meal - Mar 02, 2011
- Dinos 'considerably taller than previously thought' - Oct 01, 2010
- New findings may lead to a novel treatment for obesity - Jan 12, 2011
- Hormone could be key to keeping osteoarthritis at bay - Sep 14, 2009
- Leptin-controlled gene may help control diabetes - Jan 06, 2010
- Lower back, foot pain linked to more severe knee osteoarthritis symptoms - Nov 18, 2010
- Hormone pits fat against fat to reverse obesity - Oct 05, 2011
- Special mobility shoes can help ease knee pain, slow down osteoarthritis - Nov 08, 2010
- Shed those extra kilos before pregnancy for a healthy baby - Feb 03, 2011
- New brain pathway for regulating weight, bone mass identified - Sep 24, 2009
Tags: blood samples, body fat content, deficient mice, degenerative changes, duke university, farshid guilak, female mice, femur, joint cartilage, knee joints, knee oa, knee osteoarthritis, leptin deficiency, leptin receptor, musculoskeletal disorder, obese individuals, osteoarthritis, tibia, type mice, university researchers