Obesity and risk of incident psoriatic arthritis in US women
Annals of Rheumatic Diseases, 05/25/2012

Li W et al. – This study provides further evidence linking obesity with the risk of incident psoriatic arthritis (PsA) among US women.

• 89 049 participants were included from the Nurses Health Study II over a 14–year period (1991–2005).
• Information on body mass index (BMI), weight change and measures of central obesity (waist circumference, hip circumference and waist–hip ratio) was collected during the follow–up.
• The incidence of clinician–diagnosed PsA was ascertained and confirmed by supplementary questionnaires.

• 146 incident PsA cases were identified during 1 231 693 person–years of follow–up.
• Among all participants, BMI was monotonically associated with an increased risk of incident PsA.
• Compared with BMI less than 25.0, the RR was 1.83 for BMI 25.0–29.9 (95% CI 1.15 to 2.89), 3.12 for BMI 30.0–34.9 (95% CI 1.90 to 5.11) and 6.46 for BMI over 35.0 (95% CI 4.11 to 10.16).
• There was a graded positive association between weight change from age 18 years, measures of central obesity and risk of PsA (p for trend <0.001).
• The analysis among participants developing psoriasis during follow–up revealed a similar association (p for trend <0.01), indicating an increased risk of PsA associated with obesity among patients with psoriasis.