Weight-Loss Interventions Improve Psoriasis Severity, Quality of Life

Weight-loss interventions may improve the severity and quality of life of patients with psoriasis, new findings suggest, and such interventions may be considered for routine treatment plans.1

These recent findings were authored by a team of investigators led by Sarah Morrow, MSc, a Dermatology Specialist Registrar at Oxford University Hospitals in the UK. In this study, Morrow et al noted previous meta-analyses had only looked at behavioural weight-loss interventions and not quality-of-life.2

Additionally, Morrow and colleagues noted such reviews had not previously been conducted to assess the full weight-loss intervention range. They noted such reviews may also have not had sufficient data to meta-analyse necessary patient-reported outcomes such as dermatology life quality index (DLQI).

“This systematic review and meta-analysis aimed to address this evidence gap by synthesising and quantifying the impact of any weight-loss intervention on psoriasis severity and/or patient quality of life,” Morrow and coauthors wrote.1

Design and Findings on Weight Loss

The investigative team utilized 5 bibliographic databases and 2 clinical study registries from inception through to March 9, 2025 for their comprehensive literature search. The selection of outcomes used by the team was guided by insights gathered from previous patient focus group discussions. Ovid MEDLINE, Ovid PsycINFO, Ovid Embase, EBSCOhost CINAHL, the Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, and Web of Science Core Collection were all searched by an information specialist (EH).

This specialist used the Cochrane randomized controlled trial filter. The search strategies used in Morrow and colleagues' research were informed by prior systematic reviews in the dermatology field. Studies deemed eligible by the investigators were randomized controlled trials (RCTs) enrolling adult subjects with psoriasis. These studies, in order to be eligible, would also have looked at any form of weight-loss intervention and compared it to usual care or a less intensive weight-loss approach.

The investigative team also required such RCTs to report any shifts in patients' body weight along with at least a single measure of psoriasis disease severity or health-related quality of life. The generation of pooled estimates took place using random-effects meta-analytic models. Morrow et al's screening of RCTs carried out independently by pairs of reviewers, with data extraction being performed via Covidence. Resolution of any disagreements took place through discussion, and corresponding authors were contacted when clarification or additional information was warranted.

There were 13 RCTs in total, encompassing 1145 study subjects and contributing 14 intervention–control comparisons, which Morrow and coauthors said met their criteria for inclusion. Among the included interventions, there were 3 studies assessing pharmacologic weight-loss therapies and 11 assessing dietary modification, with 4 of the latter group also incorporating physical activity components. Across all 14 comparisons, the investigative team noted the mean difference in weight change between intervention and control groups was −6.7 kg.

The team found weight-loss interventions were linked with a significantly greater reduction in subjects' Psoriasis Area and Severity Index (PASI) scores compared with control conditions.1 They specifically highlighted a mean difference of −2.5 (95% CI, −3.8 to −1.1) and substantial heterogeneity (I² = 85.2%). Interventions for weight-loss were also shown to have substantially increased patients' probability of attaining PASI75.

Based on 6 comparisons including 681 participants, all of which saw a mean difference in weight change of −7.3 kg, Morrow et al noted the relative risk for attainment of PASI75 was 1.6 (95% CI, 1.1–2.2), with low to moderate heterogeneity (I² = 22.6%).1 Conversely, they found no statistically significant effects for participants' PASI50 or PASI100 responses.

For PASI50, there were 4 comparisons highlighted by the investigators involving 509 participants and a mean weight change difference of −4.0 kg yielded a relative risk of 1.5 (95% CI, 0.9–2.4) with considerable heterogeneity (I² = 72.8%).1 For PASI100, there were 2 comparisons comprising 334 participants and a mean weight change difference of −5.2 kg, which the team noted had a relative risk of 1.6 (95% CI, 0.3–9.7). There was no observed heterogeneity (I² = 0.0%). Both of these studies were constrained by the small number of contributing analyses.

Dermatology-specific quality of life improvements were also noted by the investigative team.1 Across the 7 comparisons highlighted by Morrow et al, including 364 participants, the mean difference in weight change was −7.8 kg and weight-loss interventions were linked with a significantly greater improvement in patients' DLQI scores compared with control groups. There was a mean difference of −5.0 (95% CI, −9.7 to −0.3) and a high level of heterogeneity (I² = 96.0%).

“Weight-loss interventions may improve skin disease and quality of life for people with psoriasis and excess weight,” the investigators concluded.1 “Clinicians should consider using these findings to counsel patients and refer them for weight-loss support when appropriate. Future research should bridge the gap between evidence and patient awareness, while addressing clinician hesitancy.”

References

1. Morrow S, Hawkins P, Scragg J, et al. Impact of weight-loss interventions on psoriasis severity: A systematic review and meta-analysis. J Eur Acad Dermatol Venereol. 2025; 00: 1–14. https://doi.org/10.1111/jdv.70247.

2. Mahil SK, McSweeney SM, Smith CH. Does weight loss reduce the severity and incidence of psoriasis or psoriatic arthritis? A Critically Appraised Topic. Br J Dermatol. 2019 Nov;181(5):946-953. doi: 10.1111/bjd.17741. Epub 2019 May 2. PMID: 30729517.