Sex-specific sleep patterns among university students in Lebanon: impact on depression and academic performance

Figures & data

Table 1 Demographic and socioeconomic characteristics of male and female respondents

Characteristics	Sex		P
	Males	Females
Age, mean ± SD (years)	20.02±1.61	19.68±1.39	<0.01
n	266	273
Employment, (%) n
Yes	39 (103)	24.5 (67)	<0.01
No	61 (161)	75.5 (206)
Household income, (%) n
Low	10.1 (25)	11.9 (31)	NS
Medium	76.9 (190)	81.2 (212)
High	13 (32)	6.9 (18)

Notes: Independent sample t-test was used to compare mean ages between males and females; chi-square test was used to compare employment and household income between the two sexes.

Abbreviations: SD, standard deviation; NS, no significance.

Table 2 Sleep variables on weekdays and weekends in males and females

Sleep variable	Males		Females		P
	Weekdays	Weekends	Weekdays	Weekends
Bedtime, mean ± min (n)	00:27±84* (257)	2:13±97** (257)	23:53±78* (267)	1:06±92** (264)	<0.01
Wake time, mean ± min, (n)	8:06±87* (260)	10:26±116 (261)	7:39±83* (257)	10:08±109 (266)	<0.01
Sleep duration, h ± min (n)	7.64±1.48 (253)	8.22±1.91** (255)	7.71±1.44 (254)	9.02±1.55** (260)	<0.01

Notes: Comparison of sleep habits between males and females on weekdays and weekends. Symbols denote significant differences between the two sexes:

* between weekdays and

** between weekends. P-values denoting independent sample t-test comparisons of sleep variables between males and females on weekdays and weekends (^* is for male-female comparison on weekdays, while ^** is for male-female comparison on weekends).

Abbreviations: min, minute; h, hour.

Table 3 CES-D and GPA scores in males and females

CES-D	Males	Females	P
No overt depression (%) (n)	41.5 (90)	29.1 (69)	<0.01
Depressive symptoms (%) (n)	58.5 (127)	70.9 (168)
GPA: score/4, mean ± SD (n)	2.65±0.61 (181)	2.80±0.61 (156)	<0.05

Notes: Chi-square test was used to compare CES-D categories between males and females; independent sample t-test was used to compare mean GPA score between the two sexes.

Abbreviations: CES-D, Center for Epidemiological Studies Depression Scale; GPA, grade point average; SD, standard deviation.

Figure 1 Scatterplot presenting CES-D and cumulative GPA by sex.

Notes: There was a significant negative correlation between CES-D scores and average GPA in females (r=−0.278, P<0.01) but not in males, with lower GPA scores correlating with higher CES-D scores (higher incidence of depression).
Abbreviations: CES-D, Center for Epidemiological Studies Depression Scale; GPA, grade point average.

Table 4 Comparison of mean GPA among the three CES-D groups in males and females

CES-D category	Males	Females	P
No overt depression	2.70±0.59 (69)	3.07±0.47 (39)	<0.01
Mild-to-moderate depression	2.60±0.73 (27)	2.81±0.47 (36)	NS
Possibility of major depression	2.65±0.56 (54)	2.65±0.72 (68)	NS

Notes: Values are expressed as mean ± SD (n). P-values for Student’s t-test denoting sex comparisons in a given CES-D category.

Abbreviations: CES-D, Center for Epidemiological Studies Depression Scale; GPA, grade point average; SD, standard deviation; NS, not significant.

Figure 2 Scatter plot presenting sleep timing and cumulative GPA by sex on both weekdays (A) and weekends (B).

Notes: Sleep time is the hour according to the 24 hour clock. There was a significant negative correlation between bedtime and GPA in males (r=−0.159, P<0.05) on weekends but not weekdays. This indicated that later sleep times on weekends were significantly correlated with poorer academic performance in males.
Abbreviation: GPA, grade point average.