Major Finding: People who developed osteoarthritis in both knees during 30 months of follow-up had a twofold increased rate of vitamin K deficiency at baseline, compared with people who did not develop osteoarthritis, and a nearly threefold increased risk of vitamin K deficiency compared with those who developed osteoarthritis in one knee.
Data Source: The 1,180 people enrolled in the MOST study who did not have osteoarthritis at baseline.
Disclosures: Dr. Neogi had no disclosures.
BRUSSELS – Vitamin K deficiency may increase the risk for developing knee osteoarthritis and for forming knee cartilage lesions, judging from the findings of a 30-month study of nearly 1,200 people at risk for knee osteoarthritis.
This apparent role of vitamin K in susceptibility to knee pathology raised the question of whether vitamin K supplementation for deficient individuals might be a “simple, effective preventive agent,” said Dr. Tuhina Neogi, a rheumatologist at Boston University.
Results from prior studies showed that low vitamin K intake and low blood levels were linked with prevalent radiographic features of hand and knee osteoarthritis. The new study made the first longitudinal examination of a potential link between plasma levels of vitamin K at baseline and incident osteoarthritis (OA) and associated pathology.
The investigators examined data that was collected from more than 3,000 people enrolled in the Multicenter Osteoarthritis (MOST) study who had an elevated risk for knee osteoarthritis at entry but had not yet developed the disease. The 1,180 people included in the current study averaged 62 years of age; 62% were women. Dr. Neogi and her associates defined vitamin K deficiency as a plasma level of phylloquinone less than 0.5 nmol/L. (Normal is 0.5-1.2 nmol/L.) At baseline, 9% of the study participants without OA had vitamin K deficiency.
The researchers made incident OA the primary end point, defined as development of a knee Kellgren-Lawrence (KL) grade of 2 or higher (including knee replacement). All people included in the analysis had a KL grade less than 2 at baseline. During 30 months of follow-up, 15% of the participants developed osteoarthritis.
In an analysis of whether or not participants developed knee OA, those with vitamin K deficiency at baseline had a 43% increased risk after adjustment. This increased risk just missed statistical significance, Dr. Neogi noted.
An additional analysis that took into account the extent of knee osteoarthritis showed that those who developed OA in both knees had a significant, nearly threefold increased risk of having vitamin K deficiency at baseline, compared with those who developed OA in one knee during follow-up. Those who had both knees affected at follow-up had a significant, twofold increased risk of vitamin deficiency, compared with people who did not develop any knee OA, she said at the congress, organized by the Osteoarthritis Research Society International.
The vitamin K–deficient participants also had a statistically significant, nearly threefold increased risk of developing new cartilage lesions on their knee MRI scans that were consistent with developing OA. They also had a 77% increased risk for showing osteophytes on their follow-up MRI scans, but this difference was not statistically significant.
Those with vitamin K deficiency had a 43% increased risk of developing knee OA, after adjustment.
Source DR. NEOGI