Duration of night sleep and cognitive performance of community older adults

Élen dos Santos Alves Corresponding author: Élen dos Santos Alves E-mail: elendutra23@gmail.com https://orcid.org/0000-0001-9696-2703

Universidade Federal de São Carlos, Programa de Pós-Graduação em Enfermagem, São Carlos, SP, Brazil.

Sofia Cristina Iost Pavarini

Universidade Federal de São Carlos, Programa de Pós-Graduação em Gerontologia, Programa de Pós-Graduação em Enfermagem, São Carlos, SP, Brazil.

Bruna Moretti Luchesi

Universidade Federal do Mato Grosso do Sul, Departamento de Medicina, Três Lagoas, MS, Brazil.

Ana Carolina Ottaviani

Universidade Federal de São Carlos, Programa de Pós-Graduação em Enfermagem, São Carlos, SP, Brazil.

Juliana de Fátima Zacarin Cardoso

Universidade Federal de São Carlos, Programa de Pós-Graduação em Enfermagem, São Carlos, SP, Brazil.

Keika Inouye

Universidade Federal de São Carlos, Departamento de Gerontologia, Programa de Pós-Graduação em Gerontologia, São Carlos, SP, Brazil.

Authors’ Contribution:

Study concept and design: Élen dos Santos Alves, Sofia Cristina Iost Pavarini, Bruna Moretti Luchesi, Ana Carolina Ottaviani, Juliana de Fátima Zacarin Cardoso, Keika Inouye. Obtaining data: Élen dos Santos Alves, Sofia Cristina Iost Pavarini, Bruna Moretti Luchesi, Ana Carolina Ottaviani, Keika Inouye. Data analysis and interpretation: Élen dos Santos Alves, Keika Inouye. Statistical analysis: Élen dos Santos Alves, Keika Inouye. Drafting the manuscript: Élen dos Santos Alves, Keika Inouye. Critical review of the manuscript as to its relevant intellectual content: Élen dos Santos Alves, Sofia Cristina Iost Pavarini, Bruna Moretti Luchesi, Ana Carolina Ottaviani, Juliana de Fátima Zacarin Cardoso, Keika Inouye.

Conflict of interest: the authors have declared that there is no conflict of interest.

Domain	N	%	Mean (SD^* * SD = Standard deviation )	Median	Variation (min-max)
Subjective sleep quality
Very good	45	28.9
Good	76	48.7
Poor	25	16.0
Very poor	10	6.4
Sleep latency (minutes)			28.2 (±35.7)	10.0	1-180
< or = 15 minutes	81	51.9
16-30 minutes	31	19.9
31-60 minutes	25	16.0
60+ minutes	19	12.2
Sleep duration (hours)			7.04 (±1.84)	7.00	3-12 hours
More than 7 hours	93	59.6
6 to 7 hours	29	18.6
5 to 6 hours	11	7.1
Less than 5 hours	23	14.7
Usual sleep efficiency (%)			88.74 (±18.15)	96.57	36.14-150.00
> 85%	107	68.6
75 to 84%	13	8.3
65 to 74%	12	7.7
< 65%	24	15.4
Sleep disorder
Absence of disorder	27	17.3
Mild disorder	114	73.1
Moderate disorder	15	9.6
Severe disorder	--	--
Use of sleep medications
Not once	120	76.9
Less than 1 time a week	5	3.2
1 to 2 times a week	2	1.3
3 times a week	28	18.0
Did not answer	1	0.6
Daytime dysfunction
Absence of daytime dysfunction	112	71.8
Mild daytime dysfunction	34	21.8
Moderate daytime dysfunction	6	3.8
Severe daytime dysfunction	3	2.0
Did not answer	1	0.6

Quartiles by hours of sleep	1^st Quartile (n=62) M=8.8h Q2=8.5h	2^nd Quartile (n=31) M=7.1h Q2=7.0h	3^rd Quartile (n=29) M=6.1h Q2=6.0h	4^th Quartile (n=34) M=4.5h Q2=5.0h		Comparative Analyses^* * Kruskal-Wallis test;
Cognitive Domains						X²	p
Attention/ Guidance						6.490	0.090
Mean	13.18	14.06	14.52	13.38	13.65
Median	13.00	14.00	15.00	13.00	13.00
SD	2.62	2.88	2.44	2.34	2.62
Memory						4.810	0.186
Mean	13.06	14.90	15.86	14.59	14.28
Median	13.00	14.00	16.00	13.00	14.00
SD	5.76	6.15	5.47	6.07	5.90
Verbal Fluency						10.060	0.018
Mean	4.92	5.84	6.90	6.15	5.74
Median	4.50	5.00	6.00	6.00	6.00
SD	3.15	2.89	2.48	2.74	2.97
Language						4.419	0.220
Mean	16.92	18.71	19.17	18.68	18.08
Median	17.00	21.00	21.00	18.50	18.00
SD	5.53	5.43	5.14	5.14	5.40
Visuospatial skills						4.523	0.210
Mean	9.53	10.77	11.17	10.06	10.20
Median	9.00	11.00	11.00	10.00	10.00
SD	3.67	3.40	2.79	3.68	3.50
ACE-R Total^† † Addenbrooke's Cognitive Exam - Revised version						6.770	0.080
Mean	57.61	64.29	67.62	62.85	61.94
Median	58.00	62.00	66.00	61.00	62.00
SD	17.57	18.08	14.84	17.04	17.3

	Non-standardized coefficients					95% confidence interval for β
	β	Standard Error	Β	t	p-value	Lower limit	Upper limit
Constant	6.237	2.680		2.328	0.021	0.942	11.532
Hours slept	-0.274	0.119	-0.171	-2.303	0.023	-0.510	-0.039
Age	0.004	0.033	0.009	0.127	0.899	-0.060	0.069
Schooling in years	0.397	0.069	0.440	5.752	0.000	0.261	0.534
*Gender^ * Gender = (1) Male;**	-0.170	0.575	-0.023	-0.295	0.768	-1.307	0.967
Use of medication^† † Use of sleep medications = (0) Does not use	0.021	0.185	0.008	0.111	0.912	-0.346	0.387

	Non-standardized coefficients		Standardized coefficient			95% confidence interval for β
	Β	Standard Error	Β	t	p-value	Lower limit	Upper limit
Constant	80.377	13.934		5.769	0.000	52.844	107.910
Hours slept	-0.960	0.619	-0.103	-1.550	0.123	-2.183	0.264
Age	-0.288	0.170	-0.113	-1.699	0.091	-0.623	0.047
Schooling in years	2.949	0.359	0.562	8.210	0.000	2.239	3.659
*Gender^ * Gender = (1) Male;**	-1.116	2.992	-0.026	-0.373	0.710	-7.028	4.795
Use of medication^† † Use of sleep medications = (0) Does not use	-0.043	0.964	-0.003	-0.045	0.964	-1.948	1.861

Brasil