A Cross-Sectional Study of Myopia and Morning Melatonin Status in Northern Irish Adolescent Children
Table 1
Sex and median (95% CI) age, SER, axial length, morning salivary melatonin concentration (pg/ml), PSQI scores, and PAC-Q scores for myopic and nonmyopic participants.
Characteristic
All participants n = 70
Myopes n = 22
Nonmyopes n = 48
value
Demographic
Sex, male/female, n
27/43
10/12
17/31
0.59†
Age (years)
14.3 (14.2–14.5)
14.3 (14.2–14.7)
14.2 (14.1–14.7)
0.44
Ocular profile
SER (DS)
+0.22 (−0.19 to 0.5)
−2.16 (−3.81 to −1.31)
+0.60 (+0.44 to +0.75)
<0.001
SER range (DS)
−5.38 to +1.88
−5.38 to −0.69
−0.37 to +1.88
AXL (mm)
23.70 (23.42–24.09)
24.52 (23.95–25.18)
23.41 (23.12–23.70)
<0.001
Melatonin profile
Melatonin conc/n (pg/ml)
4.82 (3.50–5.35)
4.52 (2.60–6.02)
4.89 (3.18–5.66)
0.91
Time saliva sample collected
08:47 (08:30−09:00)
08:50 (08:20−09:00)
08:46 (08:30−09:00)
0.93
Sleep profile
Bedtime (hh:mm)
23:30 (23:00–23:50)
23:00 (22:59−00:00)
23:30 (23:00—00:00)
0.56
Sleep latency (mins)
20 (15–30)
20 (10–30)
20 (10–30)
0.95
Wake time (hh:mm)
08:59 (8:45−9:00)
08:52 (8:00–9:00)
09:00 (8:45−9:00)
0.88
Time asleep (hh:mm)
08:30 (08:00–09:00)
09:00 (08.00—09.00)
08:15 (08:00—09.00)
0.26
Global PSQI score
4.00 (4.00–5.00)
4.00 (3.00–6.00)
4.00 (3.00–5.00)
0.83
Sleep quality (good/poor) (% poor)
22/70 (31%)
15/7 (32%)
33/15 (31%)
1.00
Activity profile
PAQ-C score
1.84 (1.50–2.27)
1.71 (1.30–2.31)
1.95 (1.48–2.46)
0.50†
SER = spherical equivalent refraction; AXL = axial length; PSQI = Pittsburgh Sleep Questionnaire Index; PAQ-C = Physical Activity Questionnaire for Children; CI = confidence interval; participants were labelled as having good sleep quality if PSQI score ≤5 and poor sleep quality if PSQI score >5 [28]; values for Mann–Whitney U test (exception for †which indicates chi-squared test). indicates significance at < 0.05.
