In patients with systemic lupus erythematosus (SLE), physical inactivity is common and associated with a significant independent risk for incident depression, according to study results published in Arthritis Care & Research (Hoboken).
Researchers sought to determine whether physical inactivity predicted incident depression in patients with SLE, and the magnitude of the associated risk.
In the current analysis, the researchers used data derived from the California Lupus Epidemiology Study (CLUES), a prospective, longitudinal cohort with confirmed SLE diagnoses. They used the data from the racially/ethnically diverse lupus cohort to evaluate whether patients without depression at baseline but with low levels of physical activity had an elevated risk of developing depression over time.
Study physicians confirmed SLE diagnoses based on the following definitions of SLE: meeting 4 or more of the 11 American College of Rheumatology (ACR) revised criteria for the classification of SLE; meeting 3 of the 11 ACR criteria with a documented rheumatologist’s diagnosis of SLE; or a confirmed diagnosis of lupus nephritis. All participants were evaluated annually either by phone or in person.
Researchers assessed physical inactivity among the participants using a single item: “I rarely or never do any physical activities”; depressive symptoms were evaluated using the Patient Health Questionnaire (PHQ-8). Researchers analyzed data of patients without depression at baseline (PHQ-8 score <10), who completed an in-person baseline assessment, and had 1 or more follow-up visits. Incident depression was defined as a PHQ-8 score of 10 or more at follow-up.
Among the 225 study participants (mean participant age, 45±15 years; 88.4% women), 184 were considered to be physically active and 41 were considered to be physically inactive. Study participants were found to be racially and ethnically diverse, with 35.1% Asian, 30.2% White, 22.2% Hispanic, 10.2% African American, and 2.2% of unspecified/other races. Overall, the 18% of the participants who reported having no physical activity (being sedentary) were more likely to be Hispanic or African American, live on or below poverty-level income, and have less educational attainment. Further, the participants from the physically inactive group were more likely to have a higher body mass index and a history of lupus nephritis.
Overall 16% of the cohort (n=37) developed depression during the 26-month follow-up. Study results showed that mean PHQ-8 scores for patients without depression at baseline did not differ according to activity status. However, patients who were inactive at baseline were significantly more likely to develop depression during the following 2 years (hazard ratio [HR], 2.89; 95% CI, 1.46-5.71). After adjustment for covariates, the association remained strong, with the sedentary group experiencing a greater than 3-fold increased risk for incident depression (HR, 3.88; 95% CI, 1.67-9.03) during the follow-up.
Study limitations included the use of patient-reported instruments to determine predictor and outcome variables; the use of depression score cut point due to which inactive study participants may have been below the cutoff for depression during the baseline assessment; and the risk for unmeasured confounding.
“Results support the importance of even low levels of physical activity and suggest an urgent need for approaches — such as health care providers’ physical activity prescriptions and referrals to appropriate community-based exercise programs — to increase physical activity in this high-risk patient population. In addition to reducing the risk [for] important physical comorbidities such as cardiovascular disease, our data [suggest] that a small increase in physical activity may also reduce the risk [for] major mental health challenges experienced disproportionally in SLE,” the researchers concluded.
Patterson SL, Trupin L, Yazdany J, et al. Physical inactivity independently predicts incident depression in a multi-racial/ethnic systemic lupus cohort. Arthritis Care Res (Hoboken). Published online January 9, 2021. doi:10.1002/acr.24555