Table 3. Associations between sleep quality, sleep duration, and uric acid levels based on the linear regression model.

Variables	Univariate			Multivariate
	β	95% CI	p-value	β	95% CI	p-value
PSQI scale
≥ 5 vs < 5	−0.096	−0.187 ~ −0.005	0.038	−0.085	−0.161 ~ −0.008	0.030
sleep duration
< 7 h vs 7–9 h	0.055	−0.035 ~ 0.145	0.231	0.106	0.031 ~ 0.181	0.006
≥ 9 h vs 7–9 h	−0.029	−0.388 ~ 0.330	0.874	0.164	−0.107 ~ 0.436	0.236
Age, years				−0.009	−0.012 ~ −0.006	<0.001
Sex, male vs female				1.401	1.321 ~ 1.480	<0.001
Obesity, yes vs no				0.518	0.423 ~ 0.614	<0.001
Hypertension, yes vs no				0.227	0.103 ~ 0.351	<0.001
Diabetes mellitus, yes vs no				−0.270	−0.042 ~ −0.125	<0.001
TC/HDL ratio				0.235	0.205 ~ 0.264	<0.001
eGFR <60 yes vs no				−0.889	−1.021 ~ −0.756	<0.001
WBC count, 10^3/μL				0.035	0.022 ~ 0.049	<0.001
Current alcohol use, yes vs no				0.216	0.120 ~ 0.313	<0.001
Current smoking, yes vs no				−0.141	−0.241 ~ −0.042	0.005
Exercise habit, yes vs no				−0.005	−0.099 ~ 0.109	0.922

Interaction between sleep duration and sex, p = 0.157

Interaction between sleep quality and sex, p = 0.364

Interaction between sleep duration and sleep quality, p = 0.153

CI: confidence interval, PSQI: Pittsburgh Sleep Quality Index, BMI: body mass index, TC: total cholesterol, HDL-C, high-density lipoprotein-cholesterol, eGFR: estimated glomerular filtration rate