Prospective cohort study on change in weight status and occurrence of habitual snoring in children.

Objective: To determine the association between the change in weight status and newly developed snoring in children.

Design: This was a prospective cohort study.

Setting: Structured interviews were conducted at participants' homes, and physical examinations were performed at The-pa Community Hospital in Southern Thailand.

Participants: Cohort subjects (n = 1076) were recruited from children born over a 1-year period between November 2000 and October 2001 in The-pa District of Songkhla Province, Southern Thailand. Data collection was performed when the child was 5 and 8.5 years old.

Main Outcome Measures: The child's snoring, weight, height and tonsillar size were examined. The change in weight status was categorised into four groups: not obese, became not obese, became obese and persistently obese.

Results: Of 1076, 983 subjects (91.4%) completed both surveys. The overall prevalence of habitual snoring decreased from 13% at age 5 to 10.9% at age 8.5 years. Of the 855 children who reported not snoring in the first survey, 61 (7.1%) had become habitual snorers. After adjusting for tonsillar size, children who had become obese or were persistently obese had a significant association with becoming a new snorer with an odds ratio of 5.8 (Confidence interval, CI, 1.3-25.8) and 11.7 (CI, 2.5-54.9), respectively.

Conclusions: Children with newly developed obesity at 8.5 years old were strongly associated with new snoring occurrence, which is similar to the findings of long-term follow-up studies in adults. Our findings support the idea that the patterns of changes in weight status and snoring development in adults begin as early as the primary school years.