Association between gastrointestinal symptoms and affectivity in patients with bipolar disorder

Table 1 Basal characteristic in patients with bipolar disorder and control subjects representative of a general population

	Bipolar disorder	Controls	P value
	(n = 136)	(n = 136)
Mean age (SD) (yr)	49.9 (14.1)	51.0 (11.4)	0.505
Women	61% (n = 83)	60% (n = 81)	0.804
Mean body mass index (SD) (kg/m2)	27.0 (5.50)	25.41 (3.19)	0.0051
Median HADS scores (IQR):
HADS-anxiety	5 (7)	4 (5)	0.0011
HADS-depression	3 (5)	3 (3)	0.0221
PSQ index (IQR)	0.27 (0.27)	NA
Median GSRS scores (IQR):
Abdominal pain	1.00 (2.00)	0.50 (1.50)	0.076
Bloating	1.00 (1.67)	0.50 (1.34)	0.419
Diarrhoea	0.50 (1.50)	0.25 (0.75)	0.0021
Constipation	0 (2.00)	0 (1.00)	0.310
Satiety	0 (1.00)	0 (0.50)	0.0191
Dyspepsia	0 (1.00)	0.33 (0.67)	0.850
Reflux	0 (1.00)	0 (0.50)	0.376
Total GSRS-IBS	9.00 (17.00)	7.00 (13.00)	0.0201
Consulters for:
Any functional GI disorder	25% (n = 34)	17% (n = 23)	0.108
IBS	12% (n = 17)	10% (n = 14)	0.582

¹Statistical significance. For each separate symptom cluster in the Gastrointestinal Symptom Rating Scale the total score was divided by the amount of items. HADS: Hospital Anxiety and Depression Scale; GSRS: Gastrointestinal Symptom Rating Scale; IBS: Irritable Bowel Syndrome; PSQ: Perceived Stress Questionnaire; IQR: Intra quartile range; NA: Not available.

Table 2 Control subjects and patients with bipolar disorder with low scores on depression and low scores on anxiety score vs patients with high scores on depression and/or high scores on anxiety

	Bipolar patients with HADS-D ≥ 8 and/or HADS-A ≥ 9 (n = 48)	Bipolar patients with HADS-D < 8 and HADS-A < 9 (n = 88)	Controls with HADS-D < 8 and HADS-A < 9 (n = 118)
Mean age (SD) (yr)	46.7 (12.8) (P = 0.048)1	51.7 (14.4)	51.5 (11.8) (P = 0.903)
Proportions of women	58% (n = 28) (P = 0.634)	62% (n = 55)	59% (n = 70) (P = 0.644)
Mean Body mass index (kg/m2) (SD)	27.2 (4.6) (P = 0.632)	26.8 (5.97)	25.6 (3.26) (P = 0.063)
Median HADS score (IQR)
HADS-anxiety	10.5 (5.0)	3.0 (4.0)	3.0 (4.0) (P = 0.660)
HADS-depression	9.0 (9.0)	2.0 (3.0)	2.0 (3.0) (P = 0.505)
PSQ index (IQR)	0.47 (0.28) (P < 0.001)1	0.20 (0.17)	NA
Median GSRS score (IQR):
Abdominal pain	1.50 (2.50) (P = 0.002)1	0.50 (1.50)	0 (1.50) (P = 0.558)
Bloating	1.67 (2.33) (P < 0.001)1	0.67 (1.33)	0.67 (1.67) (P = 0.415)
Diarrhoea	1.25 (2.25) (P < 0.001)1	0.50 (1.00)	0.25 (0.75) (P = 0.107)
Constipation	0 (2.00) (P = 0.380)	0 (1.50)	0 (1.00) (P = 0.453)
Satiety	0.50 (2.00) (P = 0.003)1	0 (0.50)	0 (0.50) (P = 0.513)
Dyspepsia	0.67 (1.33) (P = 0.002)1	0 (0.67)	0.33 (0.67) (P = 0.291)
Reflux	0 (2.13) (P = 0.098)	0 (0.88)	0 (0.50) (P = 0.796)
Total GSRS-IBS	15.0 (23.0) (P < 0.001)1	7.00 (12.0)	6.50 (13.0) (P = 0.513)
Consulters:
For any functional GI disorder	29% (n = 14) (P = 0.407)	23% (n = 20)	14% (n = 17) (P = 0.131)
IBS	17% (n = 8) (P = 0.290)	10% (n = 9)	10% (n = 12) (P = 0.995)
Median number of drugs (IQR)	3.0 (3.0) (P = 0.557)	3.0 (3.0)	1.0 (2.0) (P < 0.001)1

¹Statistical significance. For each separate symptom cluster in the Gastrointestinal Symptom Rating Scale the total score was divided by the amount of items. HADS: Hospital Anxiety and Depression Scale; GSRS: Gastrointestinal Symptom Rating Scale; GI: Gastrointestinal; IBS: Irritable bowel syndrome; IQR: Intra quartile range; NA: Not available.

Table 3 Hospital Anxiety Depression Scale scores and Perceived Stress Questionnaire index in correlation to different gastrointestinal symptom scores in patients with bipolar disorder (n = 136)

	HADS-Anxiety score.	HADS-Depression score.	PSQ index.
	rs (P value)	rs (P value)	rs (P value)
Abdominal pain	0.295 (0.001)1	0.248 (0.004)1	0.261 (0.002)1
Bloating	0.304 (< 0.001)1	0.365 (< 0.001)1	0.376 (< 0.001)1
Diarrhoea	0.334 (< 0.001)1	0.225 (0.009)1	0.268 (0.002)1
Constipation	0.099 (0.254)	0.028 (0.751)	0.063 (0.473)
Satiety	0.222 (0.010)1	0.253 (0.003)1	0.333 (< 0.001)1
Dyspepsia	0.293 (0.001)1	0.205 (0.017)1	0.287 (0.001)1
Reflux	0.245 (0.004)1	0.122 (0.160)	0.235 (0.007)1
Total GSRS-IBS score	0.336 (< 0.001)1	0.328 (< 0.001)1	0.348 (< 0.001)1

¹Statistical significance. Statistics: Spearman’s test. HADS: Hospital Anixiety and Depression Scale; GSRS: Gastrointestinal Symptoms Rating Scale; IBS: Irritable bowel syndrome; PSQ: Perceived Stress Questionnaire.

Table 4 Comparison between patients with bipolar disorder who report high respective low scores on the Gastrointestinal Symptom Rating Scale for Irritable Bowel Syndrome

	HIGH GSRS-IBS SCORE	LOW GSRS-IBS SCORE	P value
	(> 9)	( ≤ 9)
	(n = 65)	(n = 71)
Mean age (SD)(yr)	49.7 (13.7)	50.1 (14.5)	0.571
Women	71% (n = 46)	52% (n = 37)	0.0261
BMI (SD)	27.2 (4.46)	26.7 (6.32)	0.45
Median HADS scores (IQR)
Anxiety score (median)	6.0 (9.0)	4.0 (6.0)	0.0011
Depression score (median)	4.0 (8.0)	2.0 (4.0)	0.0021
PSQ index (IQR)	0.32 (0.26)	0.21 (0.23)	< 0.0011
Consulters for:
Any functional GI disorder	29% (n = 19)	21% (n = 15)	0.276
IBS	18% (n = 12)	7% (n = 5)	0.067
Bipolar type I	46% (n = 40)	54% (n = 48)	0.460
Bipolar type II	52% (n = 25)	37% (n = 23)
Medications:
Lithium	51% (n = 33)	42% (n = 31)	0.320
Neuroleptics	28% (n = 18)	20% (n = 14)	0.273
Anti-epileptics	31% (n = 20)	34% (n = 24)	0.706
SSRI	14% (n = 9)	11% (n = 8)	0.796
SNRI	9% (n = 6)	6% (n = 4)	0.519
Benzodiazepines	17% (n = 11)	6% (n = 4)	0.053
Drugs for insomnia	26% (n = 17)	10% (n = 7)	0.0141
Drugs for IBS	11% (n = 7)	1% (n = 1)	0.0281
Antacids	15% (n = 10)	7% (n = 5)	0.171
Statines	12% (n = 8)	8% (n = 6)	0.575
Levothyroxine	26% (n = 17)	13% (n = 9)	0.052
≥ 3 drugs	64% (n = 41)	54% (n = 38)	0.214

¹Statistical significance. HADS: Hospital anxiety and depression scale; GSRS-IBS: Gastrointestinal symptom rating scale- irritable bowel syndrome; PSQ: Perceived Stress Questionnaire; BMI: Body mass index; SSRI: Selective serotonin reuptake inhibitor; SNRI: Selective noradrenalin reuptake inhibitor; IQR: Intraquartile range.

Table 5 Logistic regression analysis studying factors which may influence gastrointestinal symptoms in patients with bipolar disorder

	Patients with bipolar disorder and GSRS-IBS > 9 vs patients with bipolar disorder and GSRS-IBS ≤ 9
	Unadjusted OR	Adjusted OR
Age	1.00 (0.97-1.03)	1.01 (0.97-1.04)
Sex	2.23 (1.09-4.52)1	2.37 (1.07-5.24)1
(male reference)
Body mass index	1.02 (0.95-1.09)	1.01 (0.93-1.08)
HADS-Depression ≥ 8	5.54 (2.07-14.8)1	3.64 (1.07-12.4)1
(< 8 reference)
HADS-Anxiety ≥ 9	2.89 (1.34-6.22)1	1.82 (0.64-5.22)
(< 9 reference)
PSQ index ( ≤ 0.34 reference)	2.53 (1.21-5.30)1	1.30 (0.42-3.99)
Number of Drugs ≥ 3	1.55 (0.77-3.09)	1.29 (0.59-2.80)
(< 3 reference)

¹Statistical significance. The dependent variable is high versus low score on the Gastrointestinal Symptom Rating Scale. The studied covariates were: Age (continues variable), Sex (dichotomous variable), Body mass index (continues variable), Hospital Anxiety and Depression scale score (dichotomous variable), Perceived Stress Questionnaire score (dichotomous variable) and Number of drugs (dichotomous variable with “cut off” being the median value). OR is presented with 95%CI. GSRS-IBS: Gastrointestinal symptom rating scale-irritable bowel syndrome; HADS: Hospital anxiety depression scale; PSQ: Perceived Stress Questionnaire.