Change in cardiovascular risk factors in patients who develop psoriatic arthritis: longitudinal data from the Nord-Trøndelag Health Study (HUNT)

OBJECTIVES: The aim of this population-based study was to compare changes in cardiovascular (CV) risk factors over a decade-long period in patients who developed psoriatic arthritis (PsA) and the background population. METHODS: Patients diagnosed with PsA (n=151) between 1998 and 2008 and matched controls (n=755) who participated in both the Nord-Trøndelag Health Study (HUNT) 2 (1995–1997) and HUNT3 (2006–2008) were included. Mixed linear and logistic models were used to analyse the difference in mean change between HUNT2 and HUNT3 in patients and controls for body mass index (BMI), total cholesterol (TC), triglycerides, low-density lipoprotein cholesterol (LDL-c), high-density lipoprotein cholesterol (HDL-c) and blood pressure (BP). RESULTS: At baseline (HUNT2), the patients who developed PsA compared with controls had higher BMI (27.2 vs 25.9 kg/m(2), p<0.001) and lower HDL-c (1.32 vs 1.40 mmol/L, p<0.03) and more were smokers (41.1 vs 28.5%, p<0.01). Seventy-eight per cent had skin psoriasis. The mean PsA disease duration at HUNT3 was 4.8 (+/–3.0) years. The patients who developed PsA gained less weight from HUNT2 to HUNT3 compared with the control group (2.1 vs 3.9 kg, difference in mean change −1.8 kg, 95% CI −3.9 to −0.5, p<0.01). TC, triglycerides, LDL-c or HDL-c values and BP declined in both groups, with no significant differences between groups. CONCLUSION: Longitudinal 10-year data did not show an increase in CV risk factors in patients who developed PsA compared with controls. This study implies that unfavourable CV risk factors in PsA were present before the diagnosis was established.