No strong relationship between body mass index and clinical hand osteoarthritis - results from a population-based case-control study

Objectives: The aim of this population-based case-control study was to investigate whether a high body mass index (BMI) is a risk factor for clinical hand osteoarthritis (OA). Method: Persons living in Ullensaker municipality in Norway who were aged 20-52 years in 1990 reported height and weight in 1990, 1994, 2004, and 2010 (n = 1276). Cases (clinical hand OA in 2010, n = 59) were compared to controls (participants without self-reported OA or hand pain in 2010, n = 805) with regard to the prospectively measured BMI by means of a generalized estimating equation (GEE) analysis adjusted for age, sex, time, and education. Results: The mean age of hand OA cases was 64 (SD = 7.5) years in 2010 and 78% were women. There was no association between total average BMI over the entire period and later clinical hand OA (p = 0.320). Cases had a higher mean BMI in 1990 [unstandardized B = 0.93, 95% confidence interval (CI) 0.07-1.79] and in 1994 (B = 0.75, 95% CI 0.22-1.28) but there were no differences between the groups in 2004 or 2010. Conclusions: The study lend support to the hypothesis that having a higher BMI when young or middle-aged might be associated with later hand OA.