Obesity, waist circumference, weight change and the risk of psoriasis in US women

Abstract

Background Psoriasis is a common chronic inflammatory skin disorder. Higher adiposity may increase the risk of psoriasis, but prospective data on this association are scarce. One prospective study showed that increased adiposity increased the risk of incident psoriasis in younger women, but no data are available in older women. Methods We prospectively examined the associations between body mass index (BMI), weight change, waist and hip circumference and risk of incident psoriasis in 67,300 women over a 12-year period (1996-2008) in the Nurses’ Health Study. The primary outcome was self-reported, physician-diagnosed psoriasis. Results During the 12 years of follow-up, there were a total of 809 incident psoriasis cases. There was a graded positive association between BMI (both baseline and updated) and the risk of psoriasis (both P values for trend <0.0001). Compared to women with updated BMI of <25, the multivariate RRs (relative risks) of incident psoriasis were 1.21 (95% CI, 1.03-1.43) for a BMI of 25.0 to 29.9, 1.63 (95% CI, 1.33-2.00) for a BMI of 30.0 to 34.9, and 2.03 (95% CI, 1.58-2.61) for a BMI of 35.0 or greater. Higher waist circumference, hip circumference, and waist-hip ratio were associated with a higher risk of incident psoriasis, but became non-significant after additionally adjusting for BMI. The BMI at age of 18 years was not associated with the risk of psoriasis. Weight gain since the age of 18 years was associated with an increased risk of psoriasis and RR of 10 lb gain was 1.08 (95% CI, 1.06-1.11; p<0.0001). Conclusion This large prospective study indicates that higher BMI and weight gain are risk factors for incident psoriasis in older US women.

Diet and psoriasis, part I: Impact of weight loss interventions

“…The prospective longitudinal data from incident case analysis implies that increased BMI precedes the onset of psoriasis. 7 …”

Impact of metabolic status on the incidence of psoriasis: A Korean nationwide cohort study

“…Moreover, prospective cohort studies have demonstrated that higher BMI is associated with incident psoriasis and weight gain 13,14 , along with incident psoriatic arthritis 15 . Furthermore, a prospective randomized trial reported that diet-induced weight loss for 8 weeks reduced the disease severity in 60 overweight patients with psoriasis 16 .…”

Psoriasis and comorbid diseases

“…In studies of incident psoriasis, 68–70 the risk of psoriasis was found to increase with higher BMI. 69 A meta-analysis of 16 observational studies found a pooled odds ratio [OR] for the association between psoriasis and obesity to be 1.66 (95% confidence interval [CI] 1.46–1.89) (Table II). 71 Among studies that accounted for psoriasis severity, generally defined by treatment patterns, the pooled ORs for the association between obesity and mild and severe psoriasis were 1.46 (95%CI 1.17–1.82) and 2.23 (95% CI 1.63–3.05), respectively.…”