Obesity indicators as mediators of association between daytime napping and type 2 diabetes mellitus: the Guangzhou Biobank Cohort Study

Table 1 Demographic characteristics by daytime napping in 29,355 participants in the Guangzhou Biobank Cohort Study

Characteristics	Non-nappers	Nappers	P^†
Number of participates	10,229	19,126	–
Sex, % men	19.89	31.69	< 0.001
Age, years, mean ± SD	60.7 ± 7.3	62.0 ± 7.0	< 0.001
Education, %
Primary or below	46.17	41.29	< 0.001
Middle school	47.27	48.55
College or above	6.56	10.16
Occupation, %
Manual	66.00	58.57	< 0.001
Non-manual	18.54	26.56
Others	15.47	14.86
Smoking status, %
Never	84.48	78.87	< 0.001
Former	6.69	10.47
Current	8.84	10.67
Alcohol use, %
Never	74.05	71.60	< 0.001
Former	3.34	3.65
Current	22.60	24.72
Physical activity, %
Inactive	10.26	6.83	< 0.001
Minimally active	40.13	41.26
Active	49.61	51.91
Body mass index, kg/m²	23.8 ± 3.3	23.8 ± 3.3	0.22
Waist circumference, cm	78.1 ± 8.9	79.2 ± 9.0	< 0.001
Hip circumference, cm	90.7 ± 6.3	90.8 ± 6.4	0.21
Waist-to-hip ratio	0.86 ± 0.07	0.87 ± 0.07	< 0.001
Waist-to-height ratio	0.50 ± 0.06	0.50 ± 0.06	< 0.001
Fasting plasma glucose, mmol/l, mean ± SD (N = 27,018)	5.7 ± 1.6	5.8 ± 1.7	< 0.001
Type 2 diabetes mellitus, % yes	10.70	13.38	< 0.001
Impaired fasting glucose, % yes (N = 25,700)	27.69	30.66	< 0.001

Note: Type 2 diabetes mellitus was defined as (1) fasting plasma glucose ≥7.0 mmol/L (2) self-reported diabetes diagnosed by a physician; and/or having anti-diabetic therapy
^†P value for one-way analysis of variance or chi-square test

ISSN: 1471-2458