High levels of glycated haemoglobin (HbA1c) are associated with lower knee joint cartilage quality and higher knee joint symptoms in healthy individuals.

In an asymptomatic population, we investigated the relationships between glycated haemoglobin (HbA1c) and cartilage T2 relaxation time at the knee joint level. Fourteen and 17 participants with high and normal levels of HbA1c were recruited, respectively. A blood sample was used to determine the HbA1c level. T2 relaxation time (T2) of the superficial and deep parts of the femoral cartilage in the anterior, central, and posterior topographical sites was calculated using magnetic resonance (1.5 T) images. Each participant completed a knee injury and osteoarthritis outcome score questionnaire (KOOS) and a series of biomechanical analyses while running at their self-selected speed. The group with a high level of HbA1c had a lower score of KOOS symptoms than the other group (P < 0.05). HbA1c was found to be negatively related to the KOOS symptoms score. The group with a high level of HbA1c had low T2 values in all of the investigated topographical sites of the knee femoral cartilage (P < 0.05 in all cases). T2 was negatively correlated with HbA1c levels in all investigated knee femoral cartilage regions. Our data suggest that the subjects with high levels of HbA1c were those with low knee joint symptoms and lower values of T2. These results indicate that HbA1c could be correlated with cartilage deterioration due to its ability to dehydrate collagen fibre, possibly acting as a risk factor for the development of osteoarthritis.