Prediction of Pregabalin-Mediated Pain Response by Severity of Sleep Disturbance in Patients with Painful Diabetic Neuropathy and Post-Herpetic Neuralgia

OBJECTIVE: To evaluate the predictive value of disturbed sleep on the ability of pregabalin to reduce pain associated with diabetic peripheral neuropathy (DPN) and post-herpetic neuralgia (PHN). DESIGN: A post-hoc analysis of data pooled from 16 placebo-controlled trials of pregabalin in patients with DPN or PHN. METHODS: Pain relief at endpoint was compared in patients with mild, moderate, or severe levels of baseline sleep disturbance. Sleep disturbance was based on a scale from 0-10 and scores <4, 4 to 7, and ≥7 were classified as mild, moderate, and severe, respectively. RESULTS: Pregabalin significantly reduced mean pain scores in the DPN (N = 3,056) and PHN (N = 1,471) cohorts (mean placebo-adjusted reductions were -0.73 and -1.08 for patients with DPN/PHN, respectively; both P < 0.05). The greatest extent of pain relief occurred in patients with severe sleep interference scores at baseline. Data analyses using the pooled DPN/PHN population identified a subset of patients (N = 707) exhibiting marked levels of pain relief at endpoint (mean placebo-adjusted reduction of -2.88), all of whom had severe sleep interference scores at baseline. Baseline sleep interference scores were a moderately good predictor of global patient improvement in response to pregabalin treatment in both patient cohorts. Finally, path analysis showed a high degree of association between improvements in sleep and pain relief in patients with DPN/PHN. CONCLUSION: Overall, these data suggest that the presence of comorbid sleep disturbance in patients with DPN/PHN might, in part, predict substantial pain relief in response to pregabalin treatment.