Weight-loss diet beneficial for obese PsA patients
medwireNews: Targeting weight loss with a very-low-calorie diet may improve measures of disease activity among obese patients with psoriatic arthritis (PsA), researchers report.
The study, published in Arthritis Research & Therapy, included 41 patients with a BMI of at least 33 kg/m2 (median 35.2 kg/m2) who took part in a dietary intervention in which meals were replaced with four daily portions of powder dissolved in water and consumed as soups or shakes, providing a total daily energy intake of 640 kcal, for 12–16 weeks. Participants continued to receive usual treatment with conventional or biologic DMARDs while taking part in the dietary intervention.
All patients lost weight during the study, with a median loss of 18.7 kg over 6 months from a median of 106.3 kg at study entry. The minimum amount of weight lost was 8.5 kg, and the maximum was 40.2 kg.
Eva Klingberg (University of Gothenburg, Sweden) and study co-authors found that the proportion of patients with minimal disease activity increased significantly over the study period, from 29.3% at baseline to 53.7% at the 6-month follow-up.
Minimal disease activity was defined as meeting five of the following seven criteria: tender and swollen joint counts of 1 or lower; psoriasis body surface area of 3% or less; patient pain visual analog scale (VAS) score of 15 mm or lower; patient global disease activity VAS no higher than 20 mm; Health Assessment Questionnaire (HAQ) score of 0.5 points or lower; and no more than one tender entheseal point.
The team also demonstrated that the majority of individual indicators of disease activity – including tender and swollen joint counts, HAQ score, Leeds enthesitis index, and patient VAS for global health, pain, and fatigue – improved significantly over the course of the study.
Moreover, “larger weight loss resulted in more improvement in a dose-response manner,” report Klingberg and team. Indeed, ACR20 response rates were significantly higher among patients who achieved a percentage of weight loss greater than or equal to the median of 18.6% compared with those with a lower degree of weight loss (71 vs 30%). Both percentage weight loss and percentage reduction in waist circumference were significantly correlated with the degree of reduction in DAS28-CRP score.
The researchers say that the weight-loss diet “was generally well tolerated,” with no serious adverse events occurring. When asked to score their experience of the intervention relative to their expectations, 83% of participants said that it was “much easier than expected” or “easier than expected.” However, patients “generally scored their experience of the transition from [very-low-energy diet] to normal food as harder,” note Klingberg et al.
Despite a number of limitations, including the lack of a control group and short study duration, “[t]he study supports the hypothesis of obesity as a promotor of disease activity in PsA,” write the authors.
They add that patients will be followed up for 2 years “to study long-term treatment effects” of the very-low-calorie diet.
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