A healthy dietary pattern may be associated with primary insomnia among Iranian adults: A case-control study

Objective: While it has been reported that both foods and nutrients for individuals are connected with sleep, there is no evidence regarding the association of dietary patterns, identified by factor analysis, with primary insomnia. The present study sought to evaluate the association between major dietary patterns and the chance of having primary insomnia. Methods: The present case-control study was performed using 444 people (111 cases and 333 control), aged 18 to 60 years, referred to Isfahan health centers. Dietary intake was assessed via a food frequency questionnaire in a case-control study in Isfahan, Iran. Principal component analysis was used to determine major dietary patterns. The presence of primary insomnia was measured via the insomnia severity index questionnaire, and the subjects were grouped as healthy or insomniac. Results: Three major dietary patterns were recognized, and named; Western, Iranian Traditional and Healthy, respectively. The cumulative percentage of variance explained by three dietary patterns was 48.2%. Those in second (OR = 0.30; 95%CI: 0.2-0.46) and third (OR = 0.22; 95%CI: 0.15-0.35) tertiles of healthy dietary pattern were less likely suffer with insomnia. This association remained significant only in the highest tertile after adjusting potential confounders (OR = 0.45; 95%CI: 0.32-0.95). We found no significant association between greater adherence to Western or Iranian traditional dietary patterns and primary insomnia. Conclusions: The findings showed that although no statistically significant association was observed between both Western and Iranian traditional dietary patterns with primary insomnia, people with greater adherence to the healthy dietary pattern are less likely to have primary insomnia.