Adiposity may be a risk factor for psoriasis

Takeaway

• BMI, waist circumference, waist-to-hip ratio and weight gain had a positive association with psoriasis risk.
• Maintaining normal BMI, a lean body structure and controlling excess weight gain during adulthood may help in reducing the risk for psoriasis.

Why this matters

• Psoriasis is known to be associated with increased risk for coronary heart disease, Afib, stroke, thromboembolism, and cancer.
• Adiposity results in low-grade inflammation because of overproduction of inflammatory cytokines, which may play a role in the pathogenesis of psoriasis.

Study design

• Systematic review and meta-analysis of 7 prospective studies which includes 17,636 cases and 6,95,471 participants assessing the risk for psoriasis.
• Funding: Imperial College National Institute of Health Research.

Key results

• Increasing BMI was associated with an increase in the risk for psoriasis (RR, 1.19; 95% CI, 1.10-1.28 for an increment of 5 units; P_{heterogeneity}<.0001).
• A nonlinear association was seen between BMI and psoriasis (P_nonlinearity<.0001).
• Risk for psoriasis increased with every 10 cm increase in waist circumference (RR, 1.24; 95% CI, 1.17-1.31; P_{heterogeneity}=.72), a 0.1 unit increase in waist-to-hip ratio (RR, 1.37; 95% CI, 1.23-1.53; P_{heterogeneity}=.93) and a 5 kg increase in weight (RR, 1.11; 95% CI, 1.07-1.16; P_{heterogeneity}=.15).

Limitations

• Small number of prospective studies.
• Risk for bias.