Pregnenolone Decreases Veterans' Chronic Back Pain More than Placebo

Jennifer Naylor, PhD

Use of pregnenolone resulted in a significant reduction in pain intensity rating in veterans with chronic low back pain after 4 weeks of treatment, findings of a recent randomized, double-blind, placebo-controlled clinical trial showed.

Jennifer Naylor, PhD, and a team of North Carolina-based colleagues aimed to learn whether adjunctive pregnenolone had a therapeutic for treatment of Iraq- and Afghanistan-era US military veterans with chronic low back pain. The findings suggested that the steroid hormone may be safe and effective for the treatment of such pain.

Naylor, from the Durham VA Health Care System, enrolled 94 veterans aged 18-65 years old with chronic low back pain who got treated at the Durham VA Health Care System over 6 weeks. To be eligible, the pain needed to exist most days for >6 months and a weekly mean intensity score of >4 at baseline. The pain needed to be restricted to thoracic vertebrae 6 or below or associated with radiation to the proximal part of the lower limb.

Exclusion criteria included neurological radicular signs, presumptive compression of a spinal nerve root on a simple radiogram, or compression of a spinal nerve root confirmed by specific imaging or other diagnostic techniques.

Participants were randomized to treatment condition—45 pregnenolone and 49 placebo patients were included in the results.

The investigators prescribed pregnenolone at fixed escalating dosages up to 500 mg/d.

After a 1-week single-blinded placebo lead-in period, patients in the pregnenolone cohort received 100 mg (50 mg twice daily) for 1 week, 300 mg (150 mg twice daily) for 1 week, and 500 mg (250 mg twice daily) for 2 weeks.

Each veteran filled in a pain diary and completed interviews, which included self-reported assessments and standard laboratory studies.

The team’s primary measure was the change in daily self-reported pain intensity scores on an 11-point numerical rating scale between baseline (visit 3) and visit 6. An additional outcome measure was pain interference scores, which were assessed from the Brief Pain Inventory, Short Form.

The mean age of the participants was 37.5 years old and 84 (89.4%) were male. A majority (56.4%) were Caucasian.

Mean pain diary and recall ratings at the start of the trial were 5.03 and 4.95 on a 0-10 scale. The pregnenolone condition had 8% higher pain ratings at baseline than placebo.

At baseline, unadjusted pain diary scores were 4.83 and 5.24 in the placebo- and pregnenolone-treated groups, and 4.78 and 5.15 for pain recall. Following treatment at visit 6, mean pain ratings were 4.74 in the placebo group and 4.19 in the pregnenolone group. For pain recall after treatment, the ratings were 4.86 for placebo and 4.18 for pregnenolone.

Pain scores significantly improved in the pregnenolone group compared with placebo (Least-square mean [LSM] change in pain diary rating, -.56; P=.02; LSM change in pain recall, -.7; P=.01). Interference scores for work (LSM change, .71; P=.04) and activity (LSM change, .71; P=.03) were also improved in the pregnenolone group.

Pregnenolone could serve as a safe and effective treatment to alleviate chronic low back pain in veterans, the study authors concluded.

The study, “Effect of Pregnenolone vs Placebo on Self-reported Chronic Low Back Pain Among US Military Veterans,” was published online in JAMA Network Open.