Those patients who endorsed RLS symptoms appeared to experience significantly more daytime problems (Fig 2), including being late to work, making errors at work, or missing work because of sleepiness. They also reported missing events and driving drowsy more frequently than did other respondents in the poll (p < 0.05 for all). Fifty-five percent of men and 45% of respondents reported twitching or moving their bodies frequently at night, and those who did so were more likely to be from the south.
New findings in this study are a reduced risk of RLS symptoms for those in the northeastern United States, and the association of the risk of RLS with the risk for sleep apnea and impaired daytime performance. Reading here
The NSF 2005 poll shows that, consistent with other studies, about 10% of the US adult population reports RLS symptoms. In addition, this study also demonstrates interesting regional variations in the prevalence of RLS symptoms; we think that this is the first time this has been reported. Specifically, RLS symptoms are less prevalent in the northeastern United States than in other parts of the country. There are several possible explanations for this, including that several of the factors that increase the risk of RLS (eg, obesity or cigarette smoking) are more prevalent in other areas of the country. Another possibility, however, is regional variation in the prevalence of iron deficiency. Iron deficiency is strongly associated with RLS symptoms.- A brief review of the Third National Health and Nutrition Examination Survey demonstrated a prevalence of anemia of 8.2%, 6.9%, 5.8%, and 5.6% for the south, northeast, west, and midwest, respectively. Obviously, these data are not comparable, for many reasons, including that the NSF survey is a poll with a low response rate and is subject to significant sampling errors.
Figure 2. The impact of RLS on daytime function. Those who were at risk for RLS were more likely to report fatigue, being late to work, making errors at work, or missing work because of sleepiness. They also reported missing events and driving drowsy more frequently than did other respondents in the poll (p < 0.05 for all symptoms compared to those not at risk for RLS).