Combined High-Intensity Aerobic Training and Resistance Training in Psoriatic Arthritis

• Exercise program (Behavioral): The exercise program includes two supervised sessions per week combining high-intensity interval training and strength training, plus one additional non-supervised aerobic session. The target of the high intensity intervals is 90%-95% of heart rate maximum. The strength training of major muscle groups includes 2-3 sets of 8-10 repetitions.

Primary outcomes

• Cardiopulmonary function [Baseline and 3 month]: Change in maximum oxygen uptake (VO2ml/min/kg). Higher value indicate better cardiorespiratory capacity.
• Cardiopulmonary function [Baseline and 9 month]: Change in maximum oxygen uptake (VO2ml/min/kg). Higher value indicate better cardiorespiratory capacity)

Secondary outcomes

• Waist circumference [Baseline and 3 months]: Change in waist circumference (cm) measured with a tape measure midway between the lower rib and iliac crest. A waist measurement of 80 centimeters or more for women and 94 centimeters or more for men indicate increased risk for diseases related to overweight.
• Waist circumference [Baseline and 9 months]: Change in waist circumference (cm) measured with a tape measure midway between the lower rib and iliac crest. A waist measurement of 80 centimeters or more for women and 94 centimeters or more for men indicate increased risk for diseases related to overweight.
• Body mass index (BMI) [Baseline and 3 months]: Change in Body Mass Index (BMI). Weight and height will be combined to report BMI (kg/m2). A higher score indicate higher relative weight.
• Body mass index (BMI) [Baseline and 9 months]: Change in Body Mass Index (BMI). Weight and height will be combined to report BMI (kg/m2). A higher score indicate higher relative weight.
• Body composition [Baseline and 3 months]: Change in total leanmass (%) and fatmass (%) assessed with Bioelectrical Impedance Analysis. Higher value indicate higher total leanmass and fatmass
• Body composition [Baseline and 9 months]: Change in total leanmass (%) and fatmass (%) assessed with Bioelectrical Impedance Analysis. Higher value indicate higher total leanmass and fatmass
• Triglycerides [Baseline and 3 months]: Change in triglycerides (mmol/L)
• Triglycerides [Baseline and 9 months]: Change in triglycerides (mmol/L)
• High-density lipoprotein cholesterol (HDL-C) [Baseline and 3 months]: Change in high-density lipoprotein cholesterol (HDL-C) (mmol/L)
• High-density lipoprotein cholesterol (HDL-C) [Baseline and 9 months]: Change in high-density lipoprotein cholesterol (HDL-C) (mmol/L)
• Low-density lipoprotein cholesterol (LDL-C) [Baseline and 3 months]: Change in low-density lipoprotein cholesterol (LDL-C) (mmol/L)
• Low-density lipoprotein cholesterol (LDL-C) [Baseline and 9 months]: Change in low-density lipoprotein cholesterol (LDL-C) (mmol/L)
• Total cholesterol [Baseline and 3 months]: Change in total cholesterol (mmol/L)
• Total cholesterol [Baseline and 9 months]: Change in total cholesterol (mmol/L)
• Glycosylation level of hemoglobin (HbA1c) [Baseline and 3 months]: Glycosylation level of hemoglobin (HbA1c) (mmol/mol)
• Glycosylation level of hemoglobin (HbA1c) [Baseline and 9 months]: Glycosylation level of hemoglobin (HbA1c) (mmol/mol)
• Homeostatic model assessment of insulin resistance (HOMA IR) [Baseline and 3 monhts]: Measure of insulin resistance (fasting glucose (mmol/L) and fasting insulin (mIU/ L) will be combined to report Homeostatic model assessment of insulin resistance (HOMA IR).
• Homeostatic model assessment of insulin resistance (HOMA IR) [Baseline and 9 months]: Measure of insulin resistance (fasting glucose (mmol/L) and fasting insulin (mIU/ L) will be combined to report Homeostatic model assessment of insulin resistance (HOMA IR).
• Erythrocyte Sedimentation Rate (ESR) [Baseline and 3 months]: Change in level of erytrocyte rate (ESR) (mm/h). Higher score indicate higher degree of inflammation.
• Erythrocyte Sedimentation Rate (ESR) [Baseline and 9 months]: Change in level of erytrocyte rate (ESR) (mm/h). Higher score indicate higher degree of inflammation.
• C-Reactive Protein (CRP) [Baseline and 3 months]: Change in level of of high sensitivity CRP (mg/L). Higher score indicate higher inflammation.
• C-Reactive Protein (CRP) [Baseline and 9 months]: Change in level of of high sensitivity CRP (mg/L). Higher score indicate higher inflammation.
• Cytokine levels [Baseline and 3 months]: Change in inflammatory cytokines such as Interleukin-6 (pg/mL), interleukin-10 (pg/mL), tumour necrosis factor-alpha (pg/mL).
• Disease activity [Baseline and 3 months]: Change in Disease Activity index for PSoriatic Arthritis (DAPSA) score. Calculated by summing 66/68 joints (swollen, tender), patient global assessment (VAS), pain (VAS)and CRP). A higher value indicates a higher disease activity. (Minimum: 0=no disease activity, >28= high disease activity).
• Disease activity [Baseline and 9 months]: Change in Disease Activity index for PSoriatic Arthritis (DAPSA) score. Calculated by summing 66/68 joints (swollen, tender), patient global assessment (VAS), pain (VAS)and CRP). A higher value indicates a higher disease activity. (Minimum: 0=no disease activity, >28= high disease activity).
• Muscle function lower extremities [Baseline and 3 months]: Change in the one minute sit-to-stand test (STS). Higher numbers of complete rises indicate better muscle function in lower extremities.
• Muscle function lower extremities [Baseline and 9 months]: Change in the one minute sit-to-stand test (STS). Higher numbers of complete rises indicate better muscle function in lower extremities.
• Handgrip strength [Baseline and 3 months]: Change in grip strength measured with a dynamometer (newton). Higher value indicate better grip strength.
• Handgrip strength [Baseline and 9 months]: Change in grip strength measured with a dynamometer (newton). Higher value indicate better grip strength.
• Activity limitations [Baseline and 3 months]: Change in Health Assessment Questionnaire (HAQ) (0-3). A higher score indicates more activity limitations
• Activity limitations [Baseline and 9 months]: Change in Health Assessment Questionnaire (HAQ) (0-3). A higher score indicates more activity limitations.
• Physical function [Baseline and 3 months]: Change in the Bath Ankylosing Spondylitis Functional Index (BASFI) (0-10). Higher score indicate more physical limitations
• Physical function [Baseline and 9 months]: Change in the Bath Ankylosing Spondylitis Functional Index (BASFI) (0-10). Higher score indicate more physical limitations
• Physical activity [Baseline and 3 months]: Change in self-reported weekly physical activity assessed with the International Physical Activity Questionnaire (IPAQ)-Short Form. Time spent in low, moderate, and vigorous activity is summed within each intensity category. (According to WHO guidelines, ≥150 minutes of moderate or ≥75 minutes of vigorous activity per week qualifies as health-enhancing physical activity).
• Physical activity [Baseline and 9 months]: Change in self-reported weekly physical activity assessed with the International Physical Activity Questionnaire (IPAQ)-Short Form. Time spent in low, moderate, and vigorous activity is summed within each intensity category. (According to WHO guidelines, ≥150 minutes of moderate or ≥75 minutes of vigorous activity per week qualifies as health-enhancing physical activity).
• Attitude to exercise [Baseline and 3 months]: Change in exercise believe assessed with the Exercise Health Beliefs questionnaire (20-100), Higher score represents stronger exercise beliefs.
• Attitude to exercise [Baseline and 9 months]: Change in exercise believe assessed with the Exercise Health Beliefs questionnaire (20-100), Higher score represents stronger exercise beliefs.
• Emotional experience of exercise [Baseline and 3 months]: Change in the Physical Activity Enjoyment Scale (PACES) (18-126). Higher score indicate higher degreee of enjoyment and pleasure related to exercising.
• Emotional experience of exercise [Baseline and 9 months]: Change in the Physical Activity Enjoyment Scale (PACES) (18-126). Higher score indicate higher degreee of enjoyment and pleasure related to exercising.
• Sleep quality [Baseline and 3 months]: Change in Pittsburgh Sleep Quality Index (PSQI) (0-21), Higher score indicate worse sleep quality.
• Sleep quality [Baseline and 9 months]: Change in Pittsburgh Sleep Quality Index (PSQI) (0-21), Higher score indicate worse sleep quality.
• Fatigue [Baseline and 3 months]: Change in The Multiple Fatigue Inventory (MFI-20), 4-20 for each subscale, Higher score indicates a higher degree of fatigue.
• Fatigue [Baseline and 9 months]: Change in The Multiple Fatigue Inventory (MFI-20), 4-20 for each subscale, Higher score indicates a higher degree of fatigue
• Pain intensity [Baseline and 3 months]: Visual Analogue Scale (VAS) (0-100), Higher score indicate worse pain.
• Pain intensity [Baseline and 9 months]: Visual Analogue Scale (VAS) (0-100), Higher score indicate worse pain.
• Global health [Baseline and 3 months]: Change in Visual Analogue Scale (VAS) (0-100), Higher score indicate worse health
• Global health [Baseline and 9 months]: Change in Visual Analogue Scale (VAS) (0-100), Higher score indicate worse health
• Health related quality of life [Baseline and 3 months]: Change in the 36-item Short Form Health Survey (SF-36) questionnare (0-100). A higher score indicate better health related quality of life
• Health related quality of life [Baseline and 9 months]: Change in the 36-item Short Form Health Survey (SF-36) questionnare (0-100). A higher score indicate better health related quality of life
• The impact of the disease on quality of life [Baseline and 3 months]: Change in the Dermatology Life Quality Index (DLQI) (0-30). Higher score indicate worse impairment
• The impact of the disease on quality of life [Baseline and 9 months]: Change in the Dermatology Life Quality Index (DLQI) (0-30). Higher score indicate worse impairment
• Mental health [Baseline and 3 months]: Change in the Hospital and Anxiety Depression Scale (HADS) for anxiety and depression (0-21). A higher score refers to a higher degree of distress.
• Mental health [Baseline and 9 months]: Change in the Hospital and Anxiety Depression Scale (HADS) for anxiety and depression (0-21). A higher score refers to a higher degree of distress.
• Disease related symptoms [Baseline and 3 months]: Patient Global Impression of Change (PGIC) scale (0-7) to adress changes in symtoms. Rating from very much improved (7) to very much worse (1).
• Disease related symptoms [Baseline and 9 months]: Patient Global Impression of Change (PGIC) scale (0-7) to adress changes in symtoms. Rating from very much improved (7) to very much worse (1).
• Enthesites [Baseline and 3 months]: Change in the Entesiter MASES entesit index. Palpation of 13 body sites for tenderness. (0= no tenderness, 1= tenderness presented) Higher scores indicate more widespread/tender enthesitis.
• Enthesites [Baseline and 9 months]: Change in the Entesiter MASES entesit index. Palpation of 13 body sites for tenderness. (0= no tenderness, 1= tenderness presented). Higher scores indicate more widespread/tender enthesitis.
• Skin involvement [Baseline and 3 months]: Skin involvement evaluated using the Body surface area (BSA), percentage of total body surface affected by lesions.
• Skin involvement [Baseline and 9 months]: Skin involvement evaluated using the Body surface area (BSA), percentage of total body surface affected by lesions.

Sex: All, ages: 18 Years to 65 Years

Inclusion Criteria:

* Psoriatic arthritis disease according to the CASPAR (Classification Criteria for Psoriatic Arthritis) criteria
* Age range 18-65 years
* Stable medication on anti- rheumatic drugs for >3 months prior to inclusion and throughout the first 3 months of the study

Exclusion Criteria:

* Cardiovascular disease
* Severe hypertension
* Diabetes type I
* Chronic obstructive pulmonary disease or other severe pulmonary diseases
* Arthroplasty of large joints, lower extremities
* Severe functional impairment precluding participation in high-intensity aerobic exercise
* Inability to perform a cardiopulmonary exercise testing (CPET)
* Pregnancy
* BMI ≥35 kg/m²
* Ongoing or planned initiation (within 3 months) of structured weight reduction therapy, pharmacological obesity treatment, or bariatric bypass surgery
* Already participating in regular exercise at high intensity (BORG ≥15) for >1 hour/ week during the past 6 months
* Inability to understand and read Swedish

• Annelie Bilberg, Assoc. Prof., Principal investigator, Sahlgrenska University hospital, Gothenburg