Milk consumption and progression of medial tibiofemoral knee osteoarthritis: data from the Osteoarthritis Initiative

Lu B, Driban JB, Duryea J, McAlindon T, Lapane KL, Eaton CB · Arthritis Care & Research (Hoboken)

A dose-response in women and nothing in men. Across none, ≤3, 4-6 and ≥7 glasses per week, adjusted mean loss of medial joint space width over four years was 0.38, 0.29, 0.29 and 0.26 mm (p = 0.014 for trend). In men there was no association at any level of intake. Adjusted for baseline severity, BMI and other dietary factors. Time to progression on the OARSI joint-space score pointed the same way, and the highest quartile of dietary calcium tracked with milk.

Population

2,148 Osteoarthritis Initiative participants (3,064 knees) with radiographic knee OA, followed to 48 months

Intervention

Baseline milk intake by Block Brief food-frequency questionnaire

Comparator

No milk

Limitations

Observational, single baseline food-frequency questionnaire, and the total spread across the whole exposure range is 0.12 mm of joint space over four years — real on a trend test, small against measurement error. The sex-specific finding has no stated mechanism, and a result present in women and absent in men is the shape a chance finding takes as often as a biological one. The authors call for replication; it has not been replicated. The abstract counts 3,064 knees and the results 3,087 eligible. NHLBI-funded; no conflicts.