Seasonal Variation of Psoriasis and Its Impact in the Therapeutic Management: A Retrospective Study on Chinese Patients

Figures & data

Table 1 Characteristics of the Patients by Different Psoriasis Condition in Winter/Autumn

Characteristics	Psoriasis Aggravated in Winter/Autumn
	Yes (n=1207)	No (n=1063)	P
Age (mean ± SD)	41.2±13.3	43.3±14.8	0.001
Female, n (%)	410 (34.0)	365 (34.3)	0.854
Education level, n (%)			0.007
Primary	128 (10.6)	149 (14.0)
Secondary	615 (50.9)	561 (52.8)
Higher	464 (38.5)	353 (33.2)
Age at onset (mean ± SD)	29.6±12.8	35.1±14.9	<0.001
Disease duration (mean ± SD)	11.5±8.9	8.2±8.3	<0.001
BMI (kg/m^2) (mean ± SD)	23.5±3.6	23.9±3.8	0.009
WHR (mean ± SD)	0.89±0.07	0.90±0.08	0.137
Occupation with more sunlight exposure	193 (16.0)	217 (20.4)	0.006
Comorbidities, n (%)
Hypertension	87 (7.2)	99 (9.3)	0.068
Hyperlipidemia	44 (3.6)	27 (2.5)	0.131
Diabetes	55 (4.6)	51 (4.8)	0.786
Smoking	447 (37.0)	354 (33.3)	0.063
Alcohol drinking	412 (34.1)	389 (36.6)	0.231

Note: P value by univariate logistic regression model.

Abbreviations: BMI, body mass index; WHR, waist-to-height ratio.

Table 2 Comparison of Both Psoriasis Condition in Winter/Autumn

Item	Psoriasis Aggravated in Winter/Autumn
	No	Yes
	OR	OR (95% CI)	AOR (95% CI) ^a	P
Age	1	0.99 (0.98, 0.99)	0.98 (0.97, 0.99)	<0.001
Female	1	0.98 (0.83, 1.17)	0.93 (0.75, 1.16)	0.516
Disease duration	1	1.05 (1.04, 1.06)	1.06 (1.05, 1.07)	<0.001
BMI (kg/m^2)	1	0.97 (0.95, 0.99)	0.98 (0.96, 1.00)	0.127
Occupation with more sunlight exposure	1	0.74 (0.60, 0.92)	0.78 (0.61, 0.99)	0.039
Comorbidities
Hypertension	1	0.76 (0.56, 1.02)	0.90 (0.64, 1.26)	0.536
Hyperlipidemia	1	1.45 (0.89, 2.36)	1.77 (1.06, 2.98)	0.030
Diabetes	1	0.95 (0.64, 1.40)	1.18 (0.77, 1.81)	0.461
Smoking	1	1.18 (0.99, 1.40)	1.40 (1.17, 1.68)	<0.001
Alcohol drinking	1	0.90 (0.76, 1.07)	0.93 (0.76, 1.12)	0.426

Notes: ^aAdjusted for age, educational level, disease duration, BMI and smoking. P value for adjusted OR, estimated from multivariable logistic regression model.

Abbreviations: OR, unadjusted odds ratio; AOR, adjusted odds ratio; CI, confidence interval; BMI, body mass index.

Table 3 Subgroup Analyses by Both Early and Late-Onset Psoriasis

Variables	Early-Onset Psoriasis		Late-Onset Psoriasis
	AOR (95% CI) ^a	P	AOR (95% CI) ^a	P
Age	0.99 (0.97, 1.00)	0.107	0.97 (0.95, 0.99)	0.009
Female	0.95 (0.73, 1.23)	0.696	0.91 (0.59, 1.41)	0.682
Disease duration	1.06 (1.04, 1.07)	<0.001	1.08 (1.05, 1.12)	<0.001
BMI (kg/m^2)	0.98 (0.95, 1.00)	0.099	0.99 (0.94, 1.03)	0.557
Occupation with more sunlight exposure	0.88 (0.64, 1.20)	0.403	0.64 (0.43, 0.94)	0.024
Comorbidities
Hypertension	1.06 (0.62, 1.79)	0.841	0.80 (0.50, 1.28)	0.351
Hyperlipidemia	1.70 (0.78, 3.68)	0.182	1.79 (0.88, 3.64)	0.109
Diabetes	1.16 (0.55, 2.48)	0.697	1.18 (0.69, 2.01)	0.541
Smoking	1.39 (1.11, 1.74)	0.004	1.34 (0.96, 1.86)	0.087
Alcohol drinking	0.87 (0.69, 1.10)	0.243	1.01 (0.71, 1.42)	0.965

Notes: ^aAdjusted for age, educational level, disease duration, BMI and smoking. P value for adjusted OR, estimated from multivariable logistic regression model.

Abbreviations: AOR, adjusted odds ratio; CI, confidence interval; BMI, body mass index.