Table 1: Baseline characteristics of participants with ( ) versus without ( ) symptoms of restless legs syndrome (RLS).

Restless Legs Syndrome
No Yes
Frequency/MeanPercent/SEFrequency/MeanPercent/SE

Demographic and lifestyle characteristics
 Age in years (Mean, SE)58.780.9058.651.70NS
  Race/ethnicityNS
  Non-Hispanic White4581.82%1575.00%
  Minority1018.18%525.00%
  EducationNS
  <4 years college1323.64%735.00%
  ≥4 years college4276.36%1365.00%
 Employed3970.91%1365.00%NS
 Married/Cohabiting2749.09%735.00%NS
 Mean daily intake of the following:
  Caffeine, mg (Mean, SE)148.8924.86156.4731.49NS
  Alcohol, g (Mean, SE)8.452.9320.1311.14NS
Health and reproductive history
 Reported history of:
  High blood pressure1425.45%945.00%0.10
  Depression1018.18%1050.00%0.008
  Anxiety814.55%525.00%NS
  Hormone replacement therapy1120.00%00.00%0.03
 Never pregnant1425.45%210.00%NS
 Number of pregnancies1.820.202.900.550.02
Sleep and psychosocial profiles
 Sleep Quality (PSQI)
  Sleep quality-Global5.390.518.330.750.003
  Sleep quality0.610.151.300.290.03
  Sleep latency0.920.141.050.26NS
  Sleep duration0.650.091.350.200.0005
  Sleep efficiency0.400.111.000.260.02
  Sleep disturbance1.240.071.670.110.003
  Sleep medication use0.220.060.550.210.04
  Daytime dysfunction1.290.101.650.150.06
 Insomnia (PSQI > 5) (N, %)2138.18%1785.00%0.0002
 Average sleep duration in hours (Mean, SE)7.100.156.180.250.002
 Anxiety (STAI)
  Trait34.651.2938.951.940.08
  State30.351.1832.742.45NS
 Mood (POMS)
  Total8.964.2623.899.470.09
  Tension Anxiety3.190.744.801.44NS
  Depression7.091.1011.502.820.08
  Anger/hostility5.270.708.262.47NS
  Vigor16.870.9313.551.300.06
  Fatigue8.280.9010.351.45NS
  Confusion1.760.602.801.17NS
 Perceived stress (PSS)19.601.0120.952.16NS
 Social support (DSSI)
  Social interaction8.750.5310.050.72NS
  Social support18.340.3817.790.75NS
Blood Pressure
 Systolic (mmHg)122.762.26141.854.710.0001
 Diastolic (mmHg)71.351.2278.752.570.005
Heart rate64.821.2866.652.62NS
Anthropometrics
 Waist girth (cm)103.832.20108.462.97NS
 Hip girth (cm)110.261.51113.581.43NS
 Body mass index (kg/m2)31.560.9633.311.29NS
 Prediabetic (fasting glucose 100–125 mg/dL)2138.18%1050.00%NS
 Serum ferritin levels (ng/mL)(Mean, SE)84.728.4381.0010.50NS
 Low ferritin level (<50 ng/mL)2036.36%630.00%NS

Abbreviations. DSSI: Duke Social Support Index.
NS: nonsignificant ( ).
POMS: Profile of Mood States.
PSQI: Pittsburgh Sleep Quality Index.
PSS: Perceived Stress Scale.
SE: standard error of the mean.
STAI: State-Trait Anxiety Inventory.