Rheum Round-up: CBD Yields Positive Drug Test, Race Affects TKA Discharge, and more

Here are the top stories covered by DocWire News this week in the Rheumatology section. In this edition, read about the risk of testing positive on a drug test after taking cannabidiol products, how race affects disposition after knee replacement surgery, why sleep is important to preserve bone health in women, and how exercise improves cognitive function in arthritis patients.

Cannabidiol (CBD) has become popular among patients with arthritis and other painful conditions as an alternative, sometimes ineffective treatments. CBD is not supposed to contain THC, the psychoactive ingredient in marijuana; however, some patients who take these products may screen positive for marijuana. Oral intake yielded a higher urinary concentration of CBD (mean C_max: 776 ng/mL) than vaporized intake (mean C_max: 261 ng/mL); CBD concentrations took longer to peak after oral ingestion than inhaled ingestion (five hours vs. one hour). Among 218 urine samples of patients receiving pure administration, one screened positive for ∆9-THCCOOH (20-ng/mL IA cutoff); none exceeded the 15-ng/mL confirmatory cutoff. Inhaled CBD-dominant cannabis vapor from medicines like the new CBD oil for pain resulted in nine positive screening samples at the 20-ng/mL IA cutoff, two of which screened positive at the 50-ng/mL IA cutoff. Four of these positively screened samples—two at each cutoff—also tested positive for concentrations of ∆9-THCCOOH greater than 15 ng/mL.

Black patients who undergo elective total knee arthroplasty (TKA) are more likely than white patients to be discharged to an inpatient rehabilitation facility (IRF) or skilled nursing facility (SNF) instead of home. When stratified by age and race, black patients aged <65 years, compared to white patients, were more likely to be discharged to an IRF (adjusted relative risk ratio [aRRR], 2.49 [95% CI, 1.42-4.36]; P=0.001) or SNF (aRRR, 3.91 [95% CI, 2.17-7.06]; P<0.001). Younger black patients were also more likely to require 90-day hospital readmission (adjusted odds ratio [aOR], 1.30 [95% CI, 1.02-1.67]; P=0.04) than white patients. Among the older cohort, black patients were more likely than white patients to be discharged to an SNF (aRRR, 3.30 [95% CI, 1.81-6.02]; P<0.001). Across both age groups, 90-day readmission risk was greater among patients discharged to an IRF (age <65 years: aOR, 3.62 [95% CI, 2.33-5.64]; P<0.001; age ≥65 years: aOR, 2.85 [95% CI, 2.25-3.61]; P<0.001) or SNF (age <65 years: aOR, 1.91 [95% CI, 1.37-2.65]; P<0.001; age ≥65 years: aOR, 1.55 [95% CI, 1.27-1.89]; P<0.001).

Women who do not get enough sleep may be putting themselves at risk for reduced bone mineral density (BMD) and osteoporosis. Women who slept five hours or less per night had about 0.012 to 0.018 g/cm² significantly lower whole body, total hip, femoral neck, and spine BMD than women who slept at least seven hours each night. Women with fewer hours of nightly sleep also had greater odds of low bone mass (odds ratio [OR] 1.22, 95% CI 1.03–1.45) and osteoporosis of the hip (OR 1.63, 95% CI 1.15–2.31); similar outcomes presented for spine BMD: women with little nightly sleep were more likely to have osteoporosis (adjusted OR 1.28; 95% CI 1.02–1.60). Sleep quality and DXA BMD were not significantly correlated.

Lifestyle factors may affect cognitive function in patients with rheumatoid arthritis (RA). Researchers in a new study concluded that RA patients who take part in regular physical activity are less likely to report a decline in cognitive function. Of 1,219 RA patients, 127 (10.4%) self-reported poor memory, poor concentration, or word-finding difficulties graded as “often” at the start of the study. RA patients (n = 1092, mean age = 56.5 years, 82% female, 58% college educated) who were physically active were less likely to report word-finding difficulties (P=0.0001), poor memory (P=0.01), and poor concentration (P<0.0001). Female patients were more likely than males to complain of concentration difficulties (P=0.03), and patients who were taking an anti-tumor necrosis factor therapy had lower rates of poor memory complaints (P=0.01). No independent association was observed between declining cognitive function and sleep, BMI, fatigue, depression, DAS28-CRP3, methotrexate, and corticosteroid use.