Table 3.

Results derived from GAMLSS in age subgroups when testing for associations between sleep onset latency (SOL) or slow wave energy (SWE) and MTsat values computed over the brainstem monoaminergic gray matter compartment (bmGM). Significant values are in bold.

	18–20 years (N = 104)		21–23 years (N = 133)		24–31 years (N = 84)
	Estimate	p value	Estimate	P value	Estimate	p value
SOL
bmGM	− 7.22	0.006	− 1.05	0.63	4.95	0.19
Scanner	− 0.18	0.67	− 0.04	0.81	− 0.21	0.39
Sequence	0.23	0.12	0.06	0.61	0.37	0.04
BMI	− 0.04	0.15	− 0.07	0.001	− 0.05	0.12
TST	3.1e−03	0.06	3.6e−04	0.76	2.9e−03	0.17
TIV	− 4.4e−06	0.98	7.7e−04	0.13	5.8e−04	0.41
SWE
bmGM	3.15	0.36	2.24	0.49	− 4.41	0.31
Scanner	− 0.15	0.79	− 0.01	0.96	0.31	0.33
Sequence	0.02	0.90	− 0.04	0.81	− 0.49	0.04
BMI	0.04	0.39	0.07	0.05	0.01	0.87
TST	− 3.3e−03	0.09	− 2.9e−04	0.88	− 1.9e−04	0.94
TIV	2.3e−04	2.0e−09	− 3.7e−04	< 2e−16	− 9.6e−04	< 2e−16

BMI body mass index, bmGM brainstem monoaminergic gray matter compartment, MPM sequence type of multiparameter sequence, 2 sequence types were used (N = 222 for type 1; N = 99 for type 2—see “Methods”), MRI scanner data were acquired on 2 separate scanners (N = 286 for scanner 1; N = 35 for scanner 2—see “Methods”), MTsat magnetisation transfer saturation, SOL sleep onset latency, SWE slow wave energy, TIV total intracranial volume, TST total sleep time.