High levels of saturated fatty acids associated with greater psoriasis severity

Key takeaways:

• Patients with a BMI of at least 25 kg/m² had higher levels of alanine aminotransferase and aspartate aminotransferase.
• Those with severe psoriasis had lower levels of anti-inflammatory-promoting fatty acids.

Patients with psoriasis, specifically those with a high BMI, had lower concentrations of polyunsaturated fatty acids and elevated concentrations of saturated fatty acid, which correlate to greater disease severity, according to a study.

“Although the systemic nature of the disease is not always recognized, it has been suggested that the development of psoriasis comorbidities, which significantly affect patients’ health and quality of life, may be due to inflammation,” Mariola Marchlewicz, PhD, head of the department and clinic of skin and venereal diseases at the Pomeranian Medical University in Szczecin, Poland, and colleagues wrote. “It has been suggested that an appropriate ratio of omega-3 to omega-6 fatty acids, and consequent changes in the ratio of anti-inflammatory to pro-inflammatory eicosanoids, may modulate the symptoms of inflammatory diseases, including psoriasis.”

In this study, the authors analyzed the fatty acid profile in the erythrocyte membranes of 58 adults aged 18 to 65 years with psoriasis while accounting for their BMI and disease severity. At baseline, these patients had a mean PASI score of 8.28, mean DLQI score of 8.98 and mean BMI of 27.26 kg/m². All patients received either topical (n = 30) or systemic (n = 28) psoriasis treatment, including cyclosporine A at 3 mg/kg to 5 mg/kg of body weight per day or oral methotrexate at 15 mg once a week.

After 3 months of treatment, results showed that patients with psoriasis had high levels of palmitoleic acid with a mean content of 35.93% ± 1.8% and stearic acid with a mean content of 30.9% ± 3.12%. On the other hand, these patients exhibited low levels of eicosapentaenoic acid (EPA), alpha-linolenic acid (ALA) and docosahexaenoic acid (DHA), with mean contents of 0.49% ± 0.28%, 0.63% ± 0.31% and 0.92% ± 0.64%, respectively.

The patients were also split into subgroups based on BMI, with 45% placed into the normal BMI group (BMI < 25 kg/m²) and 55% in the high BMI group (BMI 25 kg/m²). Based on these categorizations, results showed patients with high BMI had higher levels of alanine aminotransferase (40 U/L vs. 15.38 U/L; P = .0007) and aspartate aminotransferase (32.69 U/L vs. 20.13 U/L; P = .012) vs. those with normal BMI. Those with high BMI also had a significantly increased mean percentage of fatty acid content, specifically arachidonic acid at 4.08% ± 0.99% vs. those with normal BMI at 3.43% ± 0.99%.

Those in the systemic treatment group, which is associated with more severe psoriasis, had much higher BMI vs. the topical treatment group with a mean of 30.33 kg/m² ± 7.54 kg/m² vs. 24.4 kg/m² ± 7.77 kg/m²; P = .01). As a result, those in the systemic treatment group had higher concentrations of saturated fatty acids in erythrocyte membranes than those receiving topical therapy (34.19% ± 3.14% vs. 31.45% ± 2.61%; P = .01) and lower concentrations of polyunsaturated fatty acids (12.14% ± 1.91% vs. 13.07% ± 1.89%; P = .07).

DHA and EPA levels were also reduced in the systemic therapy group vs. the topical therapy group, whereas oleic acid in erythrocyte membranes was significantly elevated (14.47% ± 2.44% vs. 13.36% ± 2.19%; P = .04).

“Polysaturated fatty acids have a strong immunomodulatory effect, with EPA and DHA being primarily involved in attenuating inflammation,” the authors concluded. “Therefore, their reduced levels may be associated with an impaired anti-inflammatory mechanism, which may result in a more severe course of psoriasis.”

“This phenomenon appears to explain the observed statistical trend towards lower levels of polyunsaturated fatty acids,” the authors added, “including those of the omega-3 family, in people eligible for systemic treatment, ie, with more severe psoriasis.”