Lupus Erythematosus
Conditions
Keywords
Systemic lupus erythematosus, Sleep quality, Sleep hygiene, Lifestyle, Physical activity
Brief summary
Background: Sleep quality is a key determinant of physical and mental health, with important implications for immune regulation, psychological well-being, and overall quality of life. In systemic lupus erythematosus (SLE), sleep disturbances are highly prevalent and have been associated with poorer clinical and psychosocial outcomes. However, the specific contribution of potentially modifiable behavioral and environmental factors to sleep quality in this population has been insufficiently investigated. Objectives: To analyze the association between modifiable lifestyle, behavioral, and environmental factors and sleep quality in adults with systemic lupus erythematosus. Methods: A multicenter cross-sectional observational study will be conducted. Approximately 250 adults with systemic lupus erythematosus from different regions of Spain will be included. The primary outcome will be sleep quality, assessed using the Pittsburgh Sleep Quality Index (PSQI). Independent variables will include physical activity (International Physical Activity Questionnaire-Short Form), substance use, sleep timing and regularity, napping habits, screen exposure, and bedroom environmental conditions. Secondary variables will include risk of obstructive sleep apnea (STOP-Bang questionnaire), daytime sleepiness (Epworth Sleepiness Scale), perceived stress (Perceived Stress Scale-10), as well as clinical, sociodemographic, and anthropometric variables. Expected results: To identify behavioral and environmental factors independently associated with poor sleep quality in individuals with systemic lupus erythematosus and to estimate the prevalence of poor sleep quality in the study sample.
Interventions
OTHERAdults with systemic lupus erythematosus
Patients with systemic lupus erythematosus included in the study will complete validated questionnaires to address the study objectives.
Sponsors
Investigación en Hemofilia y Fisioterapia
Study design
Observational model
COHORT
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Adults aged ≥18 years; * A medical diagnosis of systemic lupus erythematosus (according to current clinical classification criteria); * Both sexes; * Clinically stable condition during the previous 3 months; and * Provision of written informed consent.
Exclusion criteria
* Individuals whose usual occupation involves night or rotating shift work; * A previous diagnosis of a primary sleep disorder receiving specific treatment (e.g., severe obstructive sleep apnea treated with CPAP, narcolepsy, or other central sleep disorders); and * Psychiatric or cognitive impairment that may prevent or substantially limit the accurate completion of the questionnaires
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Measurement of sleep quality | Screening visit | The primary variable will be sleep quality assessed using the Pittsburgh Sleep Quality Index (PSQI), a self-administered questionnaire composed of 19 items grouped into seven components. The global score ranges from 0 to 21 points, with scores \>5 indicating poor sleep quality. This instrument has demonstrated adequate psychometric properties in patients with systemic lupus erythematosus. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Measurement of physical activity | Screening visit | The independent variable will be physical activity assessed using the International Physical Activity Questionnaire-Short Form (IPAQ-SF), an instrument that records the frequency, duration, and intensity of physical activity performed during the previous week and allows results to be expressed in MET·minutes/week. According to the criteria established by the World Health Organization, participants will be classified into low, moderate, or high levels of physical activity. |
| Measurement of caffeine consumption | Screening visit | The independent variable will be caffeine consumption, assessed by recording the average number of daily servings of caffeinated beverages, including coffee, tea, energy drinks, and caffeinated soft drinks. Participants will report the average number of servings consumed per day according to beverage type, as well as the usual time of the last caffeine intake, given that the effect of caffeine on sleep may depend on the timing of consumption. Caffeine intake will be categorized into low, moderate, or high consumption according to standard epidemiological criteria (e.g., \<1 unit/day, 1-2 units/day, ≥3 units/day). For measurement purposes, participants will be asked questions such as: "How many caffeine units do you consume per day? (1 cup of coffee = 1 unit; 1 energy drink = 2 units)" and "At what time do you usually consume your last caffeinated beverage?" |
| Measurement of alcohol consumption | Screening visit | The independent variable will be alcohol consumption, assessed by recording both the frequency and quantity of alcohol intake. Frequency will be categorized as never, monthly, weekly, or daily. Quantity will be measured in standard drink units (1 drink = 10 g of alcohol), and participants will report the number of units consumed during a typical week. Additionally, participants will be asked about evening or nighttime alcohol consumption, specifically whether alcohol is consumed within the 3-4 hours prior to bedtime, as this timing may influence sleep quality. Example questions include: "How many units of alcohol do you consume in a typical week?" and "Do you usually consume alcohol in the evening or at night?" |
| Measurement of tobacco consumption | Screening visit | The independent variable will be tobacco consumption, assessed by recording the number of cigarettes smoked per day. Alternatively, smoking status will be categorized as non-smoker, former smoker, occasional smoker, or daily smoker. Participants will also be asked whether they smoke during the hour before going to bed, given the potential stimulating effects of nicotine on sleep. Example questions include: "How many cigarettes do you smoke per day?" and "Do you smoke during the hour before going to sleep?" |
| Measurement of medications affecting sleep | Screening visit | The independent variable will be the use of medications that may affect sleep, including hypnotics, anxiolytics, antidepressants, and stimulants. Participants will be asked whether they take any of these medications, which specific drugs they use, and the timing of administration. This variable will be primarily categorized as dichotomous (yes/no), and additional information may be collected regarding the pharmacological class and whether the medication is taken under medical prescription or through self-medication. Example questions include: "Do you take any medication to help you sleep, for anxiety, depression, or to stay awake? Please indicate which ones." and "Do you usually take these medications at night?" |
| Measurement of sleep schedule (sleep-wake rhythm) | Screening visit | The independent variable will be sleep schedule, assessed by recording participants' usual bedtime and wake-up time. Information will also be collected regarding potential variability between weekdays and weekends to evaluate the regularity of the sleep-wake rhythm. Example questions include: "What time do you usually go to bed on weekdays?" and "What time do you usually wake up on weekends?" |
| Measurement of sleep regularity (variability in sleep schedule) | Screening visit | The independent variable will be sleep regularity, assessed by evaluating the variability in habitual sleep schedules across different days of the week. Participants will be asked whether their usual bedtime varies by more than one hour between days, a criterion commonly used in circadian rhythm research. This variable will be recorded as a dichotomous measure (yes/no). Example question: "Does the time at which you usually go to bed vary by more than one hour across different days of the week?" |
| Measurement of napping habits | Screening visit | The independent variable will be napping habits, assessed by recording the weekly frequency and typical duration of daytime naps. Nap duration will be categorized into standard intervals commonly used in sleep research: \<30 minutes, 30-60 minutes, and \>60 minutes. Participants will be asked questions such as: "Do you take naps? If yes, how often per week?" and "How long do your naps usually last?" |
| Measurement of screen use before bedtime | Screening visit | The independent variable will be screen use during the hour before bedtime, assessed by recording the frequency, type of device, and duration of exposure. Frequency will be categorized as never, less than 2 days per week, several days per week, or daily. Participants will also report the type of device used (e.g., smartphone, computer, television, or tablet) and the typical duration of screen exposure (\<30 minutes, 30-60 minutes, or \>60 minutes). Example question: "During the hour before going to sleep, do you use screens? Please indicate the frequency and duration of use." |
| Measurement of bedroom environment | Screening visit | The independent variable will be bedroom environment, assessed through self-reported evaluation of environmental conditions during sleep, including light, noise, temperature, and comfort. These factors will be measured using a Likert scale ranging from 1 to 5. Participants will also be asked about the presence of potentially disruptive stimuli in the bedroom, such as the presence of a mobile phone, television, or pets in the bed. Example questions include: "Rate from 1 to 5 how much light is present in your bedroom while sleeping." and "Are there frequent noises during the night?" |
| Measurement of pre-sleep stress or cognitive arousal | Screening visit | The independent variable will be pre-sleep stress or cognitive arousal, assessed by asking participants about the presence of stress, worry, or intrusive thoughts during the period before bedtime. This variable will be measured using a Likert scale ranging from 1 to 5, where higher scores indicate greater levels of stress or cognitive activation prior to sleep. Example question: "During the hour before going to sleep, how often do you experience stress, worry, or mental rumination?" |
| Measurement of pre-sleep activities | Screening visit | The independent variable will be pre-sleep activities, assessed by recording the frequency of behaviors performed before bedtime that may negatively or positively influence sleep. Participants will report the frequency (never, rarely, sometimes, often, always) of specific activities, including heavy evening meals, vigorous nighttime physical exercise, hot showers or relaxation rituals, and relaxing activities such as reading, meditation, or listening to soft music. |
Countries
Spain
Contacts
CONTACTRubén Cuesta-Barrius, PhD
Outcome results
None listed