The aim of this study was to determine which mitochondrial DNA (mtDNA) haplogroup is associated with new development of knee osteoarthritis (OA).
Epidemiologic data and knee radiographs with the Kellgren-Lawrence (K/L) score of the Ansung cohort study were prospectively obtained from the 2nd (2005-2006) and 6th follow-up periods (2013-2014). The mtDNA was analyzed by multiplex mutagenetically separated polymerase chain reaction to determine Asian mtDNA haplogroups (M, G, D, D4, D5, M7, M8, M9, M10, N, A, N9, R, F and B). The frequency of the mtDNA haplogroup was compared between participants with knee OA (K/L score ≥2 or total knee replacement arthroplasty [OA group]) and those without knee OA (K/L < 2 [control group]) at the 6th follow-up. Multiple logistic regression was used to determine the relative risk (RR) of mtDNA haplogroups for OA by adjusting for sex, age, body mass index, smoking and metabolic syndrome.
There were 1115 participants with epidemiological data, knee radiographs and DNA samples. Of these, 572 participants had a K/L score of 0 at the 2nd follow up, and 438 underwent knee radiography at the 6th follow up. Among the 438 participants, 160 were classified as having knee OA, and 278 were classified as the control group. The haplogroup B showed a significantly higher frequency in the OA group than in the control group (unadjusted RR = 1.794, P = 0.030; adjusted RR = 2.389, P = 0.004).
Our data suggest that mtDNA haplogroup B contributed to the new development of knee OA in Koreans.