The Assessment of Risk and Predictors of Sleep Disorders in Patients with Psoriasis-A Questionnaire-Based Cross-Sectional Analysis

Abstract

Psoriasis is a chronic, inflammatory skin disease affecting 2-4% of the general population. Accompanying subjective symptoms (pruritus or pain) may cause decreased life quality including sleep disorders (SD). Sixty psoriatic patients fulfilled the following questionnaires: Pittsburgh Sleep Quality Index (PSQI), STOP BANG for the obstructive sleep apnea syndrome (OSAS) assessment, and Restless Legs Syndrome (RLS) Severity Scale. Patients' laboratory and clinical data were also investigated. All data obtained were compared to 40 participants without dermatoses. Mean PSQI, risk of OSAS, and RLS severity of psoriatics were significantly higher than in controls (p < 0.0001, p < 0.05, p < 0.05 respectively). There was a positive correlation between the time of suffering from psoriasis and the risk of OSAS (R = 0.286, p < 0.05). We did not observe any significant relationship between PSQI, risk of OSAS, or RLS and psoriasis severity assessed with PASI (Psoriasis Area and Severity Index). We identified four possible predictors of RLS: glucose, CRP and total cholesterol concentrations, and PSQI. SD are significantly more frequent in psoriatics than in people without chronic dermatological diseases but surprisingly they are not correlated with psoriasis severity. SD decrease patients' life quality and may result in serious consequences. Therefore, establishing recommendations concerning screening for SD and their predictors should be considered.

Keywords: PSQI; Pittsburgh sleep quality index; RLS; STOP BANG; obstructive sleep apnea syndrome; psoriasis; restless legs syndrome; sleep disorders.

Figure 1

Assessment of PSQI (A) and subjective sleep assessment (B) in psoriatics and control groups. Graphs A-B present data shown as Mean ± SD and values are normally distributed. ***—means the existence of a statistically significant difference between values treatment with p < 0.0001. PSQI, Pittsburgh Sleep Quality Index. Data are shown as Mean ± SD or Contingency Graph.

Figure 2

Spearman’s rank correlations between chosen basic clinical data and sleep patterns scores in psoriatic patients’ group (A), PASI I subgroup (B), and PASI II subgroup (C). Numbers on the graphs present R rank values. The blue color indicates the existence of a positive correlation between analyzed parameters, whereas the red color stands for the negative dependencies. BMI, body mass index; PASI, psoriasis area and severity index; TGs, triglycerides; HDL, high-density lipoproteins; LDL, low-density lipoproteins; CRP, C-reactive protein; ALT, alanine transaminase; AST, asparagine transaminase; PSQI, Pittsburgh Sleep Quality Index; RLS, restless legs syndrome.

Figure 3

Differences in sleep duration (A), daytime dysfunction self-assessment (B), overall impairment of daily activities (C), and usage of sleep medicines (D) between controls and psoriatic patients. **/***—means the existence of statistically significant difference between values treatment with p < 0.01; <0.0001 respectively. Data are shown as Mean ± SD or Contingency Graph.

Figure 4

Assessment of risk of OSAS in psoriatics and control groups. The graph presents data shown as Mean ± SD and values are normally distributed. *—means the existence of a statistically significant difference between values treatment with p < 0.05. OSAS, obstructive sleep apnea syndrome. Data are shown as Mean ± SD or Contingency Graph.

Figure 5

Assessment of frequency (A) and severity of RLS (B) in psoriatics and control groups. Graph B presents data shown as Mean ± SD and values are normally distributed. **—means the existence of a statistically significant difference between values treatment with p < 0.01. RLS, restless legs syndrome. Data are shown as Mean ± SD or Contingency Graph.