Table 1 General characteristics of the sample.

From: Heritability of siesta and night-time sleep as continuously assessed by a circadian-related integrated measure

  Monozygotic (n = 56) Dizygotic (n = 50) p values
Age (y.) 51 ± 6 53 ± 6 0.066
BMI (kg/m2) 26.30 ± 3.89 25.66 ± 3.65 0.404
Daytime sleep characteristics
Take siesta (Self-reported) (%) 63% 60% 0.540
Self-reported siesta duration (mm) 51 ± 23 49 ± 26 0.744
TAP-measured daytime sleep duration (mm) 49.3 ± 37.3 41.1 ± 31.6 0.296
Night-time sleep characteristics
Self-reported sleep duration (hh:mm) 6:32 ± 0:52 6:47 ± 1:04 0.159
TAP-measured night-time sleep duration (hh:mm) 7:08 ± 0.53 7:13 ± 0:55 0.691
Morning-evening questionnaire (score) 55.21 ± 8.67 56.44 ± 7.56 0.442
  1. Data are represented as means ± SD. Abbreviations: BMI, body mass index; TAP, integrated measure of temperature (T), activity (A) and position (P).