Age and gender variations of sleep in subjects without sleep disorders

Figures & data

Figure 1. Selection of the population with normal sleep. *Sleep complaints: mainly environmental disturbances. **More than twice per week. ***Documented sleep disorder (insomnia, sleep-related breathing disorders or frequent awakenings due to other problems). 4% ODI = 4% oxygen desaturation index; PLMI = periodic leg movement index. All percentages are relative to the total population subjectively (n = 5,064) or objectively (n = 2,160) investigated.

Table I. Effects of age and gender on sleep habits.

	40–50 y.o.		50–60 y.o.		60–70 y.o.		70–80 y.o.
	Women (49.2%)	Men	Women (49.5%)	Men	Women (55.3%)	Men	Women (49.1%)	Men
PSQI_category (% positive) (1)	19.6	23.6	25.6	21.6	23.7	15.2	19.4	19.6
PSQI_total score (1)	4.1 ± 2.0 [3.9–4.4]	4.3 ± 1.9 [4.0–4.5]	4.1 ± 2.1 [3.9–4.4]	4.1 ± 2.0 [3.9–4.4]	3.8 ± 2.1 [3.6–4.1]	3.8 ± 2.0 [3.5–4.0]	3.8 ± 1.9 [3.4–4.2]	3.6 ± 2.1 [3.2–3.9]
Component 1—sleep quality (1)	0.8 ± 0.6 [0.8–0.9]	0.8 ± 0.6 [0.8–0.9]	0.7 ± 0.6 [0.7–0.8]	0.7 ± 0.6 [0.7–0.8]	0.7 ± 0.5 [0.7–0.8]	0.6 ± 0.5 [0.6–0.7]	0.7 ± 0.6 [0.5–0.8]	0.6 ± 0.5 [0.5–0.7]
Component 2—sleep latency (1,2,3)	12.2 ± 9.2 [11.2–13.2]	12.1 ± 8.4 [11.1–13.0]	12.7 ± 9.5 [11.7–13.8]	11.5 ± 8.6 [10.5–12.5]	13.6 ± 9.7 [12.4–14.7]	12.1 ± 7.8 [11.1–13.1]	17.8 ± 14.5 [14.6–21.0]	12.3 ± 9.6 [10.5–14.0]
Component 3—sleep duration (1,2)	424.9 ± 57.6 [418.5–431.3]	409.7 ± 50.1 [404.2–415.2]	426.1 ± 55.1 [419.9–432.3]	408.7 ± 59.0 [401.9–415.0]	446.1 ± 61.1 [438.9–453.7]	434.3 ± 66.0 [425.8–443.0]	447.4 ± 55.6 [435.1–459.7]	447.2 ± 62.0 [435.8–458.5]
Component 4—sleep efficiency (1)	93.1 ± 7.5 [92.2–93.9]	94.1 ± 6.5 [93.4–94.8]	92.6 ± 8.4 [91.6–93.5]	93.5 ± 8.0 [92.6–94.5]	90.2 ± 8.8 [89.1–91.3]	91.3 ± 8.5 [90.2–92.5]	89.9 ± 8.5 [88.0–91.8]	89.1 ± 9.2 [87.4–90.8]
Component 5—sleep disturbances (1,3)	1.0 ± 0.4 [1.0–1.1]	0.9 ± 0.4 [0.9–1.0]	1.1 ± 0.4 [1.0–1.1]	0.9 ± 0.4 [0.9–1.0]	1.0 ± 0.4 [1.0–1.1]	1.0 ± 0.3 [1.0–1.1]	0.9 ± 0.3 [0.9–1.0]	1.0 ± 0.3 [1.0–1.1]
Component 7—daytime dysfunction (1)	0.6 ± 0.7 [0.6–0.7]	0.6 ± 0.6 [0.6–0.7]	0.5 ± 0.7 [0.5–0.6]	0.5 ± 0.7 [0.5–0.6]	0.4 ± 0.6 [0.3–0.5]	0.5 ± 0.7 [0.4–0.6]	0.5 ± 0.5 [0.4–0.6]	0.3 ± 0.5 [0.2–0.4]
Bedtime (1,2)	22:58 ± 3.2 [22:52–23:04]	23:16 ± 2.4 [23:10–23:23]	22:54 ± 1.8 [22:54–23:00]	23:07 ± 2.3 [23:00–23:12]	22:54 ± 3.8 [22:50–23:03]	23:02 ± 2.83 [22:47–22:53]	22:56 ± 4.1 [22:45–23:07]	22:54 ± 3.18 [22:50–23:07]
Time to fall asleep (2,3)	23:10 ± 2.4 [23:05–23:15]	23:29 ± 2.6 [23:23–23:35]	23:07 ± 1.8 [23:06–23:13]	23:22 ± 2.54 [23:13–23:25]	23:10 ± 2.1 [23:03–23:17]	23:20 ± 3.26 [23:07–23:20]	23:15 ± 2.0 [23:02–23:25]	23:10 ± 3.2 [23:04–23:21]
Wake-up time (1,2)	6:45 ± 14.0 [6:38–6:51]	6:42 ± 2.9 [6:35–6:48]	6:35 ± 14.0 [6:39–6:51]	6:36 ± 2.7 [6:26–6:41]	7:24 ± 1.7 [7:16–7:31]	7:12 ± 3.3 [7:02–7:17]	7:30 ± 1.1 [7:19–7:41]	7:30 ± 3.3 [7:25–7:32]
Epworth Sleepiness Scale (1,2,3)	6.6 ± 3.7 [6.2–7.1]	6.3 ± 0.2 [5.9–6.7]	6.0 ± 3.7 [5.5–6.4]	6.3 ± 3.7 [5.8–6.7]	4.6 ± 3.2 [4.2–5.0]	5.5 ± 3.4 [5.1–6.0]	3.9 ± 2.7 [3.3–4.5]	5.3 ± 3.5 [4.6–5.9]
Epworth Sleepiness Scale category (% positive) (1,2,3)	14.1	11.7	12.8	12.3	3.9	6.6	2.3	6.4
Horne and Ostberg (1,2)	57.0 ± 8.9 [56.0–58.0]	57.8 ± 8.3 [56.9–58.7]	58.9 ± 8.4 [58.0–59.9]	59.6 ± 8.5 [58.7–60.6]	60.5 ± 9.2 [59.4–61.6]	62.2 ± 7.6 [61.2–63.2]	62.1 ± 8.5 [60.2–63.9]	64.2 ± 7.1 [62.9–65.5]
Definite morning	6.8	6	10.9	11.3	15.8	17.2	19.3	23.1
Moderate morning	15.2	13.3	14.7	19.6	20.3	24.5	28.4	28.7
Neither	49.6	54.4	51.9	49.9	45.6	45.6	37.6	39.9
Moderate evening	14.9	17.7	15.2	11.6	12	8	8.3	7.7
Definite evening	13.4	8.6	7.3	7.7	6.3	4.6	6.4	0.7

Data are presented as mean ± SD [95% confidence interval], or percentage where specified. All subjects who declared taking sleep medication (prescribed or not) were not considered as ‘not complaining’, so they were not included in the analysis. If analysis showed a significant effect, it was specified as: 1) age differences; 2) gender differences; 3) age × gender differences, P < 0.05.

Epworth Sleepiness Scale positive = ESS score > 10; PSQI_positive = PSQI global score > 5 (for each PSQI component, the score varies between 0 and 3, with 0 being the best and 3 being the worst estimate).

Figure 2. (A) The prevalence of morning (black line) and evening type (red line) according to age (n = 2,966). Morning types were all ‘definite’ or ‘moderate’ morning type participants, and all participants included in ‘definite’ and ‘moderate’ evening type were considered as evening type. Black asterisks mark significant differences between age groups (multinomial logistic regression, P < 0.001). (B) Declared sleep duration (minutes): black bars represent men and red bars women; black lines connect significantly different age groups, and asterisks mark gender differences (two-way analysis of variance with factors ‘age group’, P < 0.05, ‘gender’, P < 0.05, and ‘age group × gender’, P = n.s.). (C) Daytime functioning (red line) and sleep quality (black line) improves with aging (asterisks mark significant differences between age groups, chi-square test, P < 0.001; each point represents the percentage of the participants rating their daytime functioning and sleep quality as very good). (D) The prevalence of excessive daytime sleepiness decreases with aging: black bars represent men and red bars women; asterisks mark gender differences (chi-square test, P < 0.001). Excessive daytime sleepiness was considered based on the ESS scores, using a cut-off of 10.

Table II. Effects of age on chronotype.

	50–59 y.o. versus 40–49 y.o.		60–69 y.o. versus 40–49 y.o.		70–79 y.o. versus 40–49 y.o.
	OR [95% CI]	P value	OR [95% CI]	P value	OR [95% CI]	P value
Chronotype		0.002		P < 0.0001		P < 0.0001
Morning type	1.78 [1.33–2.40]		3.24 [2.36–4.46]		5.95 [3.77–9.42]
Neither	1.28 [0.99–1.64]		1.52 [1.13–2.03]		1.84 [1.17–2.90]
Evening type	1		1		1

Multinomial logistic regression, unadjusted model; ‘evening type’ was used as reference for chronotype; ‘definite morning’ and ‘moderate morning’ were unified in ‘morning type’ category; also, ‘evening type’ resulted from unification of ‘definite evening’ and ‘moderate evening’ participants. Data are presented as odds ratio [95% CI]. P values correspond to age group differences.

Table III. Effects of age and gender on variables assessed by polysomnography.

	40–50 y.o.		50–60 y.o.		60–70 y.o.		70–80 y.o.
	Women (50.1%)	Men	Women (55.1%)	Men	Women (56.1%)	Men	Women (54.6%)	Men
Total sleep time (min) (1,2)	428.6 ± 60.7 [420.6–436.6]	398.5 ± 67.4 [389.5–407.3]	421.7 ± 63.7 [413.5–429.8]	388.4 ± 66.7 [377.9–398.8]	406.5 ± 67.5 [395.1–418.0]	381.4 ± 80.5 [363.3–399.4]	390.5 ± 72.0 [368.8–412.1]	379.6 ± 62.4 [358.5–400.7]
Sleep efficiency (%) (1,2)	90.4 ± 6.1 [89.6–91.2]	88.5 ± 8.3 [87.4–89.5]	88.7 ± 7.6 [87.7–89.6]	86.9 ± 8.9 [85.3–88.3]	83.0 ± 10.3 [81.2–84.7]	78.3 ± 12.4 [75.5–81.1]	78.7 ± 12.8 [74.8–82.5]	77.6 ± 11.7 [73.6–81.5]
Wake after sleep onset (min) (1,2)	46.3 ± 32.2 [42.1–50.6]	52.9 ± 40.1 [47.6–58.2]	54.8 ± 38.8 [49.9–59.8]	59.9 ± 43.4 [53.1–66.7]	85.8 ± 56.4 [76.2–95.4]	105.9 ± 63.9 [91.5–120.2]	107.8 ± 70.0 [86.8–128.9]	114.5 ± 74.7 [89.2–140.0]
Sleep onset latency (to any stage) (min)	15.0 ± 19.2 [12.5–17.6]	13.8 ± 16.0 [11.6–15.9]	16.5 ± 22.7 [13.6–19.4]	13.6 ± 14.1 [11.4–15.8]	19.0 ± 25.2 [14.7–23.3]	17.2 ± 20.1 [12.7–21.7]	18.8 ± 16.6 [13.8–23.8]	14.8 ± 15.6 [9.5–20.0]
Sleep onset latency (to stage 2) (min)	18.8 ± 20.2 [16.1–21.4]	19.1 ± 21.3 [16.2–21.8]	19.8 ± 23.5 [16.8–22.8]	18.8 ± 18.2 [15.9–21.6]	23.3 ± 29.7 [18.3–28.3]	21.0 ± 21.4 [16.2–25.8]	22.0 ± 17.1 [16.8–27.1]	18.4 ± 15.6 [13.1–20.7]
Latency to SWS (min) (1,2)	21.5 ± 20.4 [18.8–24.3]	25.1 ± 30.1 [21.1–29.1]	18.1 ± 15.5 [16.1–20.0]	26.4 ± 32.7 [21.2–31.5]	33.3 ± 40.2 [26.5–40.1]	37.6 ± 52.9 [25.8–49.5]	46.7 ± 63.8 [27.5–65.9]	54.0 ± 63.7 [32.4–75.5]
Latency to REM sleep (min) (1,2,3)	81.8 ± 36.1 [77.1–86.6]	81.3 ± 39.3 [76.1–86.5]	85.6 ± 43.1 [80.1–91.0]	79.3 ± 32.7 [72.5–86.1]	86.8 ± 57.5 [77.1–96.5]	84.0 ± 55.4 [71.5–96.4]	112.0 ± 78.7 [88.4–135.6]	79.1 ± 45.8 [63.6–94.6]
Stage 1 (%) (1,2)	8.5 ± 3.7 [8.0–9.0]	10.9 ± 4.9 [10.2–11.5]	9.0 ± 4.0 [8.5–9.6]	12.4 ± 5.8 [11.5–13.3]	9.9 ± 4.6 [9.2–10.7]	13.6 ± 6.9 [12.1–15.2]	10.1 ± 5.3 [8.5–11.7]	14.9 ± 5.9 [13.0–17.0]
Stage 2 (%) (1)	43.8 ± 7.5 [42.8–44.8]	44.2 ± 7.7 [43.1–45.2]	43.7 ± 7.5 [42.7–44.7]	44.2 ± 8.0 [42.9–45.5]	46.7 ± 9.5 [45.2–48.4]	48.1 ± 10.8 [45.7–50.6]	48.0 ± 11.5 [44.6–51.5]	48.0 ± 12.3 [43.9–52.1]
SWS (%) (1,2,3)	22.5 ± 7.7 [21.5–23.5]	22.0 ± 7.3 [21.1–23.0]	23.6 ± 7.7 [22.6–24.6]	21.4 ± 7.7 [20.1–22.6]	20.4 ± 7.9 [19.0–21.7]	16.4 ± 7.9 [14.6–18.2]	21.0 ± 8.8 [18.4–23.7]	15.6 ± 7.9 [12.9–18.3]
REM sleep (%) (1,2)	25.2 ± 4.7 [24.6–25.8]	22.9 ± 5.1 [22.3–23.6]	23.6 ± 5.0 [23.0–24.2]	22.0 ± 5.3 [21.2–22.8]	22.9 ± 5.7 [22.0–23.9]	21.8 ± 5.9 [20.5–23.1]	20.9 ± 5.7 [19.2–22.6]	21.4 ± 6.8 [19.1–23.7]
Oxygen desaturation index 4% (n/h) (1,2)	1.6 ± 2.3 [1.3–1.9]	4.3 ± 3.8 [3.8–4.8]	3.1 ± 3.1 [2.7–3.5]	4.8 ± 4.1 [4.2–5.5]	4.3 ± 3.7 [3.6–4.9]	6.2 ± 4.2 [5.3–7.1]	5.2 ± 3.7 [4.1–6.3]	6.3 ± 4.4 [4.8–7.8]
Periodic leg movements index (n/h) (1)	1.8 ± 3.5 [1.3–2.2]	2.3 ± 3.9 [1.7–2.8]	2.2 ± 3.8 [1.8–2.7]	2.1 ± 3.8 [1.5–4.7]	3.3 ± 4.6 [2.5–4.1]	2.9 ± 4.3 [1.9–3.8]	4.0 ± 5.1 [2.4–5.5]	4.6 ± 5.3 [2.8–6.4]
Total arousal index (n/h) (2)	14.6 ± 6.1 [13.8–15.4]	17.8 ± 7.2 [16.8–18.8]	15.1 ± 5.8 [14.4–15.8]	18.2 ± 5.9 [17.3–19.2]	16.8 ± 6.2 [15.7–17.8]	20.6 ± 8.9 [18.7–22.6]	19.1 ± 7.4 [16.8–21.3]	21.2 ± 8.0 [19.3–24.8]
Spontaneous arousals (n/h) (1)	10.9 ± 4.7 [10.2–11.5]	10.5 ± 4.8 [9.9–11.2]	9.9 ± 4.3 [9.4–10.5]	10.1 ± 4.4 [9.4–10.8]	10.5 ± 4.6 [9.7–11.3]	11.2 ± 5.7 [9.9–12.4]	11.1 ± 5.5 [9.5–12.8]	11.8 ± 5.2 [10.0–13.6]
Respiratory arousal index (n/h) (1,2)	1.9 ± 2.4 [1.6–2.2]	5.1 ± 4.8 [4.4–5.7]	3.4 ± 3.3 [2.9–3.8]	6. ± 4.8 [5.3–6.8]	4.3 ± 4.0 [3.6–1.3]	7.8 ± 7.2 [6.2–9.4]	5.6 ± 4.1 [4.3–6.8]	7.7 ± 7.0 [5.4–10.1]
Periodic leg movements arousals (n/h) (1,2)	0.8 ± 1.8 [0.5–1.0]	0.5 ± 1.4 [0.4–0.7]	0.7 ± 1.4 [0.5–0.8]	0.4 ± 1.0 [0.3–0.6]	1.0 ± 1.8 [0.7–1.3]	0.6 ± 1.3 [0.3–0.9]	1.7 ± 2.5 [0.9–2.4]	1.4 ± 2.5 [0.6–2.3]

Two-way ANOVA with factors ‘age group’, ‘gender’, and interaction (n = 1,147) for the main polysomnographic variables. Significant effects are specified as: 1) age differences; 2) gender differences; 3) age × gender differences, P < 0.05. Data are presented as mean ± SD [95% confidence interval].

SWS = slow-wave sleep; REM = rapid eye movement.

Figure 3. Effect of age (A) and gender (B) on NREM-relative EEG spectral power (n = 776, logarithmic scale). Down-oriented triangles connect frequencies for which power densities were significantly decreased with age, while up-oriented triangles connect frequencies for which power densities were significantly increased with age. Effect of age (C) and gender (D) on REM sleep-relative EEG spectral power. Down-oriented triangles connect frequencies for which power densities were significantly decreased with age, while up-oriented triangles connect frequencies for which power densities were significantly increased with age (P < 0.05). EEG power spectra were normalized by dividing the power in each 0.25 Hz bin by the total power for NREM and REM sleep, respectively, over the 0.75–30 Hz frequency range. (Two-way ANOVA for factors ‘age group’, P < 0.05, ‘bin’, P < 0.0001, and ‘age group × bin’, P < 0.05, and for factors ‘gender’, ‘bin’, and their interaction, P < 0.05). Overall, 60–69 y.o. and 70–80 y.o. groups differed significantly from 40–49 y.o. and 50–59 y.o.