Exploring the Impact of Modifiable Factors on Serum BDNF in Psychiatric Patients and Community Controls

Figures & data

Figure 1 Study flow diagram.

Table 1 Participant Demographic and Clinical Characteristics at Baseline (N = 311)

Demographics	Total Sample	Psychiatric Patients n = 220	Community Controls n = 91
Age in years; mean (SD)	45.2 (15.6)	44.7 (14.6)	46.5 (17.9)
Female sex; n (%)	158 (50.8)	113 (51.4)	45 (49.5)
Married or common law; n (%)	111 (35.9)	63 (28.9)	48 (52.8)
Unemployment; n (%)	191 (62.2)	154 (71.3)	37 (40.7)
MINI-diagnosed disorder; n (%)
Psychotic Disorder^a	4 (1.5)	4 (2.2)	0 (0.0)
Mood Disorder^b	90 (32.5)	88 (46.8)	2 (2.3)
Anxiety Disorder^c	52 (19.1)	49 (26.6)	3 (3.4)
Eating Disorder^d	1 (0.4)	1 (0.6)	0 (0.0)
Antisocial Personality Disorder^e	20 (7.3)	17 (9.2)	3 (3.4)

Notes: ^aData available for 272 participants, 183 psychiatric patients and 89 community controls; ^bData available for 277 participants, 188 psychiatric patients and 89 community controls; ^cData available for 273 participants, 184 psychiatric patients and 89 community controls; ^dData available for 271 participants, 182 psychiatric patients and 89 community controls; ^eData available for 274 participants, 185 psychiatric patients and 89 community controls.

Abbreviation: SD, standard deviation.

Table 2 Participant BDNF Levels and Modifiable Factors at Baseline (N = 311)

Characteristics	Total Sample	Psychiatric Patients n = 220	Community Controls n = 91
Serum BDNF level (ng/mL); mean (SD)	24.26 (7.34)	24.05 (7.48)	24.77 (7.00)
BMI^a; mean (SD)	28.8 (8.1)	29.3 (8.8)	27.6 (6.1)
Current smoker^b; n (%)	95 (31.4)	84 (39.6)	11 (12.1)
Physical activity^c; n (%)
Sedentary	53 (17.1)	48 (21.9)	5 (5.5)
Non-sedentary	257 (82.9)	171 (78.1)	86 (94.5)
Psychotropic Medications; n (%)	237 (76.2)	217 (98.6)	20 (22.0)
Antidepressant	165 (53.1)	151 (68.6)	14 (15.4)
Antipsychotic	143 (46.0)	142 (64.6)	1 (1.1)
Mood stabilizer	99 (32.8)	94 (42.7)	5 (5.5)
Sedative-hypnotic	191 (61.4)	187 (85.0)	4 (4.4)
Prazosin	9 (2.9)	8 (3.6)	1 (1.1)
Food Intake in servings per day^d; mean (SD)
Fruits	4.73 (1.5)	4.63 (1.5)	4.96 (1.4)
Refined Grains	3.5 (1.7)	3.44 (1.7)	3.65 (1.6)
Fish	2.64 (1.2)	2.55 (1.2)	2.84 (1.1)
Nuts	2.81 (1.5)	2.57 (0.6)	3.35 (1.4)

Notes: ^aData available for 306 participants, 215 psychiatric patients and 91 community controls; ^bData available for 303 participants, 212 psychiatric patients and 91 community controls; ^cData available for 310 participants, 219 psychiatric patients and 91 community controls; ^dData available for 294 participants, 203 psychiatric patients and 91 community controls.

Abbreviations: SD, standard deviation; BDNF, brain-derived neurotrophic factor; BMI, body mass index.

Table 3 Regression Model of Factors Associated with Serum BDNF Level in All Participants (N = 311)

Covariate	Unadjusted			Adjusted for Age, Sex and Psychiatric Status
	Estimated Beta-Coefficient	95% CI	p	Estimated Beta-Coefficient	95% CI	p
Psychiatric Status	−0.711	−2.514, 1.091	0.438	–	–	–
Age (years)	−0.033	−0.085, 0.020	0.218	–	–	–
Female Sex	1.338	−0.297, 2.973	0.108	–	–	–
BMI	−0.030	−0.132, 0.072	0.566	−0.024	−0.127, 0.079	0.650
Smoker	1.352	−0.440, 3.144	0.139	1.638	−0.248, 3.524	0.088
Sedentary activity	−2.469	−4.636, −0.301	0.026*	−2.486	−4.698, −0.275	0.028*
Antidepressant Medications	−0.709	−2.351, −0.934	0.397	−0.588	−2.479, 1.302	0.541
Food Intake (servings per day)
Fruits	0.172	−0.615, 0.960	0.667	0.067	−0.727, 0.860	0.869
Fish	0.136	−0.985, 1.257	0.811	0.184	−0.946, 1.314	0.749
Nuts	0.509	−0.541, 1.560	0.341	0.498	−0.553, 1.549	0.352
Refined Grains	0.220	−0.687, 1.127	0.633	0.258	−0.668, 1.185	0.584

Note: *p-value <0.05.

Abbreviations: CI, confidence interval; BMI, body mass index.

Table 4 Age- and Psychiatric Status-Adjusted Regression Model of Factors Associated with Serum BDNF Level Stratified by Sex (N = 311)

Covariate	Male (n = 153)			Female (n = 158)
	Estimated Beta-Coefficient	95% CI	p	Estimated Beta-Coefficient	95% CI	p
Psychiatric Status^a	−1.897	−4.319, 0.525	0.124	0.000	−2.707, 2.707	1.000
Age (years)^b	−0.072	−0.146, 0.002	0.055	−0.001	−0.077, 0.075	0.982
BMI	−0.164	−0.050, 0.379	0.132	0.072	−0.195, 0.050	0.244
Smoker	1.572	−0.933, 4.077	0.217	1.631	−1.207, 4.468	0.258
Sedentary activity	−1.415	−4.609, 1.779	0.383	−3.178	−6.285, −0.071	0.045*
Antidepressant Medications	3.195	0.511, 5.880	0.020*	−3.104	−5.752, −0.457	0.022*
Food Intake (servings per day)
Fruits	−0.198	−1.279, 0.881	0.717	0.324	−0.843, 1.492	0.584
Fish	−0.162	−1.621, 1.296	0.826	0.550	−1.201, 2.300	0.536
Nuts	0.491	−0.908, 1.890	0.489	0.430	−1.157, 2.018	0.593
Refined Grains	−0.194	−1.401, 1.013	0.751	0.818	−0.606, 2.243	0.258

Notes: ^aAdjusted for age only; ^bAdjusted for psychiatric status only; *p-value <0.05.

Abbreviations: CI, confidence interval; BMI, body mass index.