A study of more than 2,000 people suggests that people whose index finger is shorter than their ring finger are up to twice as likely to suffer from the condition, which is the most common form of arthritis.
Index to ring finger length ratio (referred to as 2D:4D) is a trait known for its differences between the sexes. Men typically have shorter second than fourth digits; in women, these fingers tend to be about equal in length. Smaller 2D:4D ratios have intriguing hormonal connections, including higher prenatal testosterone levels, lower oestrogen concentrations, and higher sperm counts. Reduction in this ratio has also been linked to athletic and sexual prowess.
Researchers at The University of Nottingham now conducted a case-control study to assess the relationship between the 2D: 4D ratio and the risk of knee and hip osteoarthritis (OA). Their findings suggest that having a relatively long ring finger to index finger ratio raises the risk for developing OA of the knee, independent of other risk factors and particularly among women.
For the study, 2,049 case subjects were recruited from hospital orthopaedic surgery lists and a rheumatology clinic in Nottingham. All had clinically significant symptomatic OA of the knees or hips, requiring consideration of joint replacement surgery. Recruited from hospital lists of patients who had undergone intravenous urography (IVU) within the past five years, 1,123 individuals with no radiographic evidence of hip or knee OA, no present hip or knee symptoms, and no history of joint disease or joint surgery served as a control group.
The study population was comprised of both men and women, with an average age of approximately 67 years for cases and 63 years for controls.
As the first study to examine the relationship between 2D:4D length ratio and OA, it also raises questions. “The underlying mechanism of the risk is unclear,” Professor Michael Doherty, lead researcher, stressed, “and merits further exploration.”
MEDICA.de; Source: University of Nottingham