Increased frequency of restless legs syndrome in primary hyperparathyroidism: A case-control study

While primary hyperparathyroidism (PHPT) is associated with neuropsychiatric symptoms and sleep disorders, its relationship with restless legs syndrome (RLS) has not been sufficiently investigated.

The study was conducted as a cross-sectional observational study, including 73 PHPT patients and 57 healthy controls. RLS's secondary causes were carefully excluded. All participants were evaluated by a neurologist, and the diagnosis of RLS was made according to the criteria of the "International Restless Legs Syndrome Study Group". The "Pittsburgh Sleep Quality Index" (PSQI) was used to measure sleep quality, and the "Epworth Sleepiness Scale" (ESS) was used to measure daytime sleepiness.

The mean ages of the PHPT group and the control group in the study (53.2 ± 10.3 years and 52.3 ± 13.6 years, respectively, p = 0.7) and the gender distributions were similar (male/female: 20.6%/79.4% and 31.6%/68.4%, respectively, p = 0.2). The incidence of RLS was significantly higher in the PHPT group compared to the control group (45.2% vs. 10.5%; p < 0.001). Total PSQI scores were elevated in PHPT patients, with notable impairment specifically in the sleep duration and sleep disturbance subcomponents; however, ESS scores showed no significant difference between groups. PHPT (odds ratio 9.2) and female gender were identified as independent risk factors for the presence of RLS.

RLS is significantly more common in PHPT patients compared to healthy controls. PHPT is also associated with impaired sleep quality and sleep continuity. Present research results suggest that RLS and sleep disorders should also be considered in the clinical evaluation of PHPT.