Relationship between sleep duration and clustering of metabolic syndrome diagnostic components

Figures & data

Table 1 Characteristics of participants by group according to sleep duration – HIPOP-OHP study

	Sleep durationa
	<6 hours	6 to <7 hours	7 to <8 hours	>8 hours	Total	P value
Person N	680	1779	1488	409	4356
Age (years)	40.4 ± 9.5	41.4 ± 9.4	41.4 ± 9.6	42.4 ± 10.0	41.3 ± 9.6	0.010
Female (%)	22.1	21.8	14.7	10.8	18.4	<0.001
SBP (mmHg)	117 ± 17	117 ± 17	119 ± 17	121 ± 16	118 ± 17	0.003
DBP (mmHg)	72 ± 12	72 ± 12	73 ± 12	75 ± 12	73 ± 12	<0.001
High BP (%)	24.3	24.1	25.8	28.4	25.1	0.275
Dyslipidemia (%)	29.6	25.9	26.3	28.4	26.8	0.251
IGT (%)	7.5	6.0	6.3	7.3	6.5	0.501
BMI (kg/m^2)	23.3 ± 3.5	23.0 ± 3.2	22.8 ± 3.0	22.8 ± 3.0	23.0 ± 3.2	0.004
BMI ≥ 25 kg/m^2 (%)	27.2	23.1	19.5	21.8	22.4	<0.001
BMI ≥ 30 kg/m^2 (%)	4.7	2.5	2.3	1.5	2.7	0.003
IPAQ	1.3 ± 0.6	1.3 ± 0.6	1.4 ± 0.7	1.3 ± 0.7	1.3 ± 0.6	0.005
Current smoking (%)	42.9	44.9	47.8	57.5	46.7	<0.001
Alcohol intake (mL/day)	17.9 ± 32.6	17.6 ± 27.9	20.9 ± 29.7	27.7 ± 39.9	19.7 ± 30.7	<0.001
MetS No Ab	0.88 ± 0.99	0.79 ± 0.97	0.78 ± 0.95	0.86 ± 1.00	0.81 ± 0.97	0.064
MetS No Bc	0.66 ± 0.82	0.58 ± 0.79	0.61 ± 0.78	0.66 ± 0.82	0.61 ± 0.79	0.116

Notes: The chi-square statistical test for nominal variables and one way analysis of variance for continuous variables were performed to assess whether there were significant differences among the groups stratified by sleep duration. We defined four components for MetS in this study as follows: 1) High BP, SBP ≥ 130 mmHg, or DBP ≥ 85 mmHg, or the use of an antihypertensive drug; 2) dyslipidemia, HDL < 40 mg/dL, or TG ≥ 150 mg/dL, or on medication for dyslipidemia; 3) IGT, fasting blood sugar concentration ≥ 110 mg/dL, or if less than 8 hours after meals ≥ 140 mg/dL), or on medication for diabetes mellitus; 4) overweight, defined as BMI ≥ 25 kg/m², or obesity, defined as BMI ≥ 30 kg/m².

a Sleep duration = average sleeping hours per night on weekdays.

b MetS No A = number of MetS component including overweight component.

c MetS No B = number of MetS component including obesity component.

Abbreviations: BP, blood pressure; SBP, systolic blood pressure; DBP, diastolic blood pressure; IGT, impaired glucose tolerance; BMI, body mass index; IPAQ, International Physical Activity Questionnaire classification; MetS, metabolic syndrome; HDL, high-density lipoprotein; TG, triglycerides; IGT, impaired glucose tolerance.

Table 2 Independent factors that contributed to the number of metabolic syndrome diagnostic components and sleep duration and lifestyle habits – results of Poisson regression analysis

Variable	Overweight				Obesity
	Model 1a		Model 2b		Model 1a		Model 2b
	βc	P value	βc	P value	βc	P value	βc	P value
Male gender	0.639	<0.001	0.752	<0.001	0.670	<0.001	–0.154	0.805
Age (year)	0.026	<0.001	0.026	<0.001	0.028	<0.001	–0.049	<0.001
Sleep group <6 hours (680)	0.141	<0.001	0.162	<0.001	0.152	0.007	0.641	0.008
6 to <7 hours (1779)	Ref		Ref		Ref		Ref
7 to <8 hours (1488)	–0.057	0.152	–0.045	0.270	–0.007	0.878	–0.032	0.893
≥8 hours (409)	–0.006	0.920	–0.050	0.435	0.020	0.769	–0.328	0.460
IPAQ			–0.238	0.034			–0.351	0.547
Current smoking			–0.115	0.559			–0.588	0.459
Alcohol intake (mL/day)			0.018	<0.001			0.041	0.307
IPAQ × male			0.176	0.078			0.119	0.804
Alcohol intake × male			–0.017	<0.001			–0.045	0.258
Smoking × male			0.158	0.382			0.271	0.689

Notes: Results of analysis by Poisson regression models on associations between the number of MetS diagnostic components (including overweight or obesity component) and lifestyle are shown.

a Model 1, adjusted for sex and age.

b Model 2, adjusted for the variables in model 1 plus IPAQ, current smoking, alcohol intake, and interaction terms (IPAQ × male, alcohol intake × male, current smoking × male).

c β = regression coefficient.

Abbreviations: IPAQ, International Physical Activity Questionnaire classification; MetS, metabolic syndrome.

Table 3 Independent factors that contributed to high BP, dyslipidemia, IGT, overweight, obesity and sleep duration including other lifestyle habits – results of logistic regression analysis

Variable	High BP (N = 1094)		Dyslipidemia (N = 1169)		IGT (N = 282)		Overweight (N = 974)		Obesity (N = 116)
	OR	95% CI	OR	95% CI	OR	95% CI	OR	95% CI	OR	95% CI
Male gender	2.68a	1.58–4.52	3.70a	2.02–6.74	1.96	0.39–9.77	1.72a	1.01–2.95	0.86	0.25–2.92
Age	1.05a	1.04–1.06	1.03a	1.02–1.03	1.09a	1.08–1.12	1.02b	1.01–1.02	0.95a	0.93–0.97
Sleep <6 hours (594)	1.09	0.88–1.36	1.27b	1.03–1.56	1.49b	1.03–2.15	1.31b	1.06–1.61	1.90a	1.18–3.05
6 to <7 hours (1557)	Ref		Ref		Ref		Ref		Ref
7 to <8 hours (1297)	1.06	0.90–1.26	0.96	0.82–1.14	1.01	0.74–1.37	0.79b	0.66–0.94	0.97	0.61–1.54
≥8 hours (344)	1.01	0.76–1.31	0.97	0.75–1.25	0.95	0.59–1.50	0.83	0.63–1.09	0.72	0.30–1.72
IPAQ	0.65b	0.42–0.99	0.60b	0.37–0.98	1.76	0.45–6.91	0.89	0.58–1.37	0.70	0.23–2.21
Current smoking	0.64	0.30–1.39	1.22	0.54–2.73	1.02	0.12–8.95	0.82	0.39–1.72	0.56	0.12–2.63
Alcohol intake	1.02	0.99–1.04	1.02	0.99–1.05	1.04	0.95–1.14	1.03	1.00–1.05	1.04	0.96–1.13
IPAQ × male	1.41	0.98–2.03	1.34	0.86–2.05	0.60	0.16–2.25	1.14	0.78–1.67	1.12	0.44–2.87
Alcohol × male	0.99	0.97–1.01	0.98	0.95–1.01	0.96	0.88–1.05	0.97b	0.95–0.99	0.96	0.88–1.03
Smoking × male	1.35	0.67–2.70	1.06	0.50–2.22	0.98	0.12–7.92	1.29	0.67–2.51	1.31	0.35–4.93

Notes: ORs and 95% CIs of analyses by logistic regression models on associations between high BP, dyslipidemia, IGT, overweight (BMI ≥ 25 kg/m²), obesity (BMI ≥ 30 kg/m²) and sleep duration including other lifestyle habits and interaction terms (IPAQ × male, alcohol intake × male, current smoking × male) are shown. All covariates included are shown in this Table.

a P < 0.01

b P < 0.05.

Abbreviations: OR, odds ratio; CI, confidence interval; BP, blood pressure; IGT, impaired glucose tolerance; BMI, body mass index; IPAQ, International Physical Activity Questionnaire classification.