Effect of UVB Therapy on Inflammatory Markers in Psoriasis
Effect of UVB Therapy on Inflammatory Markers in Psoriasis
We studied the anthropometric, metabolic and atherogenic profile of a group of Spanish patients with moderate and severe psoriasis treated with NB-UVB phototherapy, compared with controls matched by gender, age and BMI, and excluding subjects with a list of other inflammatory diseases. We further studied possible changes in those values due to UVB phototherapy.
From January 2010 to May 2011, and excluding the months with higher solar irradiance (April–September), we recruited patients with moderate and severe psoriasis admitted for NB-UVB therapy to the Phototherapy Unit of Hospital Parc Taulí. During the same period, we recruited controls without psoriasis matched for gender, age and BMI.
The hospital Research Committee approved the study.
Inclusion and exclusion criteria are specified in Table 1. Controls matching the anthropometric characteristics of the patients were recruited among hospital workers and patients admitted to the dermatology department for treatment or follow-up of diseases other than psoriasis. We wanted to study a real population, and therefore did not exclude patients or controls with diabetes, hypertension or dyslipidaemia. The subjects displayed a pathological profile matching their age, gender and BMI. Matched controls provided a control population that was similar to the patients, with the main difference being the presence of cutaneous psoriasis.
Patients admitted to the phototherapy unit had to have no history of photosensitivity and had to be available for treatment 2 or 3 days a week. They were advised to not make any nutritional or lifestyle changes that could interfere with the results during the treatment period.
NB-UVB radiation (311 nm) was administered using a Waldmann 7002 cabin (Waldmann Medizintechnik, Villingen-Schwenningen, Germany). Energy output was measured with a standard intrinsic UV meter. Initial dose was dependent on phototype, and dosage increases followed the guidelines of the Spanish Photobiology Group.
Weight, BMI, waist circumference (measured at the midpoint between the lower border of the rib cage and the iliac crest) and arterial pressure were recorded in all subjects at the time of inclusion. Body fat content was analysed by bioelectrical impedance with a tetrapolar foot-to-foot device (Tanita TBF-300; Tanita Corporation, Tokyo, Japan). Phototype was recorded following the Fitzpatrick scale. Sun exposure was recorded estimating the mean number of hours spent outdoors, and dividing the subjects into three groups: (i) low (1 h or less daily); (ii) moderate (1–3 h daily); and (iii) high (> 3 h daily).
Fasting blood and urine samples were taken for assessment of the parameters shown in Table 2. Clinical and laboratory evaluations were repeated on patients after completion of the phototherapy course, no later than 1 week after the last therapeutic session.
The Psoriasis Area and Severity Index (PASI) was calculated by the same dermatologist for patients before and after treatment, together with a Dermatology Life Quality Index (DLQI) questionnaire.
Data sets were tested for normality with the Kolmogorov–Smirnov test. All parameters were normally distributed. Student's paired t-test for quantitative variables and the McNemar test for qualitative variables were used. Linear regression analysis further determined multivariate relationships. Statistical calculations were performed with SPSS 17.0 software (SPSS Inc., Chicago, IL, U.S.A.). All P-values were two-sided and P < 0·05 was considered statistically significant. Results are presented as mean ± SD.
Materials and Methods
We studied the anthropometric, metabolic and atherogenic profile of a group of Spanish patients with moderate and severe psoriasis treated with NB-UVB phototherapy, compared with controls matched by gender, age and BMI, and excluding subjects with a list of other inflammatory diseases. We further studied possible changes in those values due to UVB phototherapy.
Recruitment
From January 2010 to May 2011, and excluding the months with higher solar irradiance (April–September), we recruited patients with moderate and severe psoriasis admitted for NB-UVB therapy to the Phototherapy Unit of Hospital Parc Taulí. During the same period, we recruited controls without psoriasis matched for gender, age and BMI.
The hospital Research Committee approved the study.
Inclusion and Exclusion Criteria
Inclusion and exclusion criteria are specified in Table 1. Controls matching the anthropometric characteristics of the patients were recruited among hospital workers and patients admitted to the dermatology department for treatment or follow-up of diseases other than psoriasis. We wanted to study a real population, and therefore did not exclude patients or controls with diabetes, hypertension or dyslipidaemia. The subjects displayed a pathological profile matching their age, gender and BMI. Matched controls provided a control population that was similar to the patients, with the main difference being the presence of cutaneous psoriasis.
Patients admitted to the phototherapy unit had to have no history of photosensitivity and had to be available for treatment 2 or 3 days a week. They were advised to not make any nutritional or lifestyle changes that could interfere with the results during the treatment period.
Treatment
NB-UVB radiation (311 nm) was administered using a Waldmann 7002 cabin (Waldmann Medizintechnik, Villingen-Schwenningen, Germany). Energy output was measured with a standard intrinsic UV meter. Initial dose was dependent on phototype, and dosage increases followed the guidelines of the Spanish Photobiology Group.
Clinical Evaluation and Laboratory Studies in Patients and Controls
Weight, BMI, waist circumference (measured at the midpoint between the lower border of the rib cage and the iliac crest) and arterial pressure were recorded in all subjects at the time of inclusion. Body fat content was analysed by bioelectrical impedance with a tetrapolar foot-to-foot device (Tanita TBF-300; Tanita Corporation, Tokyo, Japan). Phototype was recorded following the Fitzpatrick scale. Sun exposure was recorded estimating the mean number of hours spent outdoors, and dividing the subjects into three groups: (i) low (1 h or less daily); (ii) moderate (1–3 h daily); and (iii) high (> 3 h daily).
Fasting blood and urine samples were taken for assessment of the parameters shown in Table 2. Clinical and laboratory evaluations were repeated on patients after completion of the phototherapy course, no later than 1 week after the last therapeutic session.
The Psoriasis Area and Severity Index (PASI) was calculated by the same dermatologist for patients before and after treatment, together with a Dermatology Life Quality Index (DLQI) questionnaire.
Statistical Analyses
Data sets were tested for normality with the Kolmogorov–Smirnov test. All parameters were normally distributed. Student's paired t-test for quantitative variables and the McNemar test for qualitative variables were used. Linear regression analysis further determined multivariate relationships. Statistical calculations were performed with SPSS 17.0 software (SPSS Inc., Chicago, IL, U.S.A.). All P-values were two-sided and P < 0·05 was considered statistically significant. Results are presented as mean ± SD.
