Association of glucose homeostasis and metabolic syndrome with knee cartilage defects and cartilage volume in young adults.
To describe the associations of glucose homeostasis and metabolic syndrome (MetS) measures with knee cartilage defects and cartilage volume in young adults. Fasting blood biochemistry, waist circumference and blood pressure measures were collected 4-5 years prior to knee magnetic resonance imaging (MRI) scans. Blood measures included levels of glucose, insulin, triglyceride and high-density lipoprotein cholesterol (HDL-C). Homeostatic model assessment 2-insulin resistance (HOMA2-IR), HOMA2-beta cell function (HOMA2-β), HOMA2-insulin sensitivity (HOMA-S) and MetS were calculated or defined. Knee cartilage defects and cartilage volume were measured from MRI scans. Data were analysed using log binomial or linear regressions. Among 328 participants (47.3% were females, aged 26-36 years at baseline), 40 (12.7%) had hyperglycaemia and 21 (6.7%) had MetS. Glucose homeostasis measures (except fasting glucose) were associated with tibiofemoral cartilage defects (fasting insulin: relative risk (RR) 1.05, 95% confidence interval (CI) 1.01 to 1.08; HOMA2-IR: 1.44, 1.08 to 1.92; HOMA2-β: 2.59, 1.33 to 5.07; HOMA2-S: 0.36, 0.18 to 0.72), but not patellar cartilage defects. There were no associations between glucose homeostasis measures and knee cartilage volume. High waist circumference (RR 2.32, 95% CI 1.18 to 4.54) and low HDL-C (RR 1.99, 95% CI 1.08 to 3.69) were associated with tibiofemoral cartilage defects, but no other associations were observed between MetS or its components and cartilage defects or volume. Insulin resistance, high waist circumference and low HDL-C were associated with higher risk of tibiofemoral cartilage defects, suggesting glucose homeostasis and some MetS components may affect early cartilage damage in young adults.