Restless Legs Syndrome and Type 2 Diabetes

A study published in the Journal Sleep (vol. 30, No. 7, 2007, p. 866-871) investigated the association between Restless Legs Syndrome (RLS) and Type 2 Diabetes. The study, authored by Dr. Giovanni Merlino, MD and colleagues from the University of Udine, Italy, analyzed the characteristics of RLS in diabetic patients and the possible risk factors in the development of RLS in diabetics.

RLS is Characterized by an Uncomfortable Feeling in the Legs

RLS is a very common disorder that often occurs in families due to inherited problems with a neurochemical called Dopamine. The symptoms include an uncomfortable feeling in the legs or arms, and/or an irresistible urge to move while at rest. Both adults and children experience RLS, which is associated with a number of other conditions like ADHD and depression.

These “difficult-to-describe” symptoms occur more often in the evening or night, and may be temporarily relieved by rubbing, movement, or massage. RLS may also result from other conditions such as diabetes, neuropathy, kidney disease, iron deficiency, or even central nervous system trauma.

RLS Found to be Highly Associated with Type 2 Diabetes

The Italian researchers studied one hundred twenty-four consecutive outpatients with diabetes at a university diabetic outpatient clinic and eighty-seven consecutive controls. RLS was diagnosed in close to 18% of the diabetic patients compared to only 5.5% of the controls.

They also discovered that RLS was independently associated with Type 2 Diabetes. Multivariate statistical analysis excluded additional confounding variables such as age, gender, body mass index (BMI), levels of triglycerides, and presence of polyneuropathy. Even after controlling for these variables, RLS was still found to be highly associated with Type 2 Diabetes.

The authors also studied whether Polyneuropathy – a generalized disorder of the peripheral nerves – is more common in diabetics with or without RLS. They showed that polyneuropathy only partially explains the increased prevalence of RLS in Type 2 Diabetics.

RLS and Diabetes Set Up a Vicious Cycle

Many of those afflicted by RLS complain of poor sleep quality with frequent awakenings and difficulty in initiating and maintaining sleep. This chronic sleep deprivation has been shown to be linked to increased risk of cardiovascular disease and mortality.

The link between RLS and cardiovascular disease may be related to chronic sleep loss. The documented increase of hypertension, and now diabetes, in RLS could provide an explanation for the increased risk of vascular disease in RLS.

Treating RLS will Improve Diabetes

The authors suggest that by treating RLS symptoms in diabetics, the risk of mortality due to vascular disease may be reduced.

Although this study demonstrated an increased prevalence of RLS in diabetics, it is also noted in the literature that Restless Legs Syndrome itself may be a cause for Type 2 Diabetes.