Knee Osteoarthritis Predicted by Finger Length Ratios
Mechanism of elevated risk unclear
MONDAY, Jan. 7 (HealthDay News) -- Individuals whose index finger is shorter than their ring finger appear to have an increased risk of osteoarthritis of the knee, according to an article published in the January issue of Arthritis & Rheumatism.
Weiya Zhang, Ph.D., of the University of Nottingham in Nottingham, U.K., and colleagues compared the index to ring finger length (2D:4D) ratio in 2,049 individuals with symptomatic, radiographically confirmed knee or hip osteoarthritis to that of 1,123 control patients without osteoarthritis. Hand radiographs were classified into three patterns: type 1 (index finger longer than the ring finger), type 2 (index and ring finger lengths equal), and type 3 (index finger shorter than the ring finger).
The type 3 pattern was associated with an increased risk of knee osteoarthritis (odds ratio 1.94), especially in women (OR, 3.05) compared to men (OR, 1.45), and the risk was independent of other well-established osteoarthritis risk factors.
"The mechanism that accounts for this association is unknown," the authors write. "Apart from an indirect sex hormone effect mediated by biomechanical factors and effects on joint connective tissue metabolism, the 2D:4D length ratio could also associate with osteoarthritis if it were a phenotypic marker for genetic variation in non-endocrine mechanisms."
This study was supported by AstraZeneca, Macclesfield, U.K.