Efficacy of inhaled Lavandula angustifolia Mill. Essential oil on sleep quality, quality of life and metabolic control in patients with diabetes mellitus type II and insomnia

Ethnopharmacologic relevance: Lavandula angustifolia Mill (lavender) odor was traditionally used as sleep enhancer. Previous studies have shown interaction between insomnia, quality of life and control of diabetes mellitus (DM). Insomnia is suggested to increase the risk of depression and decrease the quality of life in diabetic patients. The aim of this study was to evaluate the efficacy of inhaled Lavandula angustifolia Mill. as a complementary therapy for insomnia in diabetic patients. Methods: In a randomized crossover placebo-controlled clinical trial, 52 patients with type II diabetes mellitus (DM) and insomnia, defined as Pittsburgh Insomnia Rating Scale-20(PIRS-20)>5,were treated with inhaled lavender or placebo for two periods of 4 weeks duration with one week interval as washing period. Sleep quality, quality of life and mood status were assessed by PIRS-20, WHO Quality of Life-BREF(WHOQOL-BREF) Questionnaire and Beck Depression Inventory (BDI) scale respectively, at baseline and end of each period of study. Fasting blood glucose (FBS), calorie intake and physical activity were measured before and after the interventions. Results: At the end of study, data of 37 patients (all received both lavender and placebo in cross-over design) were analyzed. Based on crossover analysis the first treatment was not effective on the second treatment. Inhaled lavender resulted in a significant better outcome compared to placebo according to mean PIRS-20, WHOQOL-BREF and Beck Depression Inventory scores in both crossover arms. Likewise there was a significant better outcome in PIRS-20 domains for quality and quantity of sleep after Inhaled lavender compared to placebo. No significant improvement was observed in fasting glucose in lavender compared to placebo administration period. Conclusion: Inhaled lavender can improve sleep quality and quantity, quality of life and mood in diabetic patients suffering from insomnia with no significant effect on metabolic status.