Chronic pain and cognitive impairment: a cross-sectional study in people living with HIV

Figures & data

Table 1. Comparison of demographic information and HIV characteristics between participants with and without cognitive impairment.

	Total cohort n = 140	Cognitive impairment n = 57	No cognitive impairment n = 83	p-value
Age, years	52.2 (9.7)	49.2 (10.2)	54.2 (9.0)	0.003*
Male, n (%)	116 (83)	43 (75)	73 (88)	0.054
BMI, kg/m^2	25.2 (4.8)	25.6 (5.7)	24.9 (4.1)	0.412
Years since HIV diagnosis	16.9 (9.0)	16.4 (9.5)	17.2 (8.7)	0.583
Years between diagnosis and treatment	3.8 (4.4)	4.0 (4.1)	3.8 (4.6)	0.807
CD4 count cells/mm^3	670 (301)	656 (253)	679 (331)	0.673
CD4 nadir cells/mm^3	218 (162)	224 (168)	208 (158)	0.383
Proportion subjects undetectable viral load, n (%)	124 (89)	49 (86)	75 (90)	0.422
Proportion with AIDS defining illness, n (%)	47 (34)	18 (32)	29 (35)	0.679
Employment, n (%)
Employed	77 (55)	24 (42)	53 (64)	0.024*^##
Sick	37 (27)	21 (36)	16 (19)
Unemployed	9 (6)	6 (11)	3 (4)
Retired	16 (11)	6 (11)	10 (12)
Education level, n (%)
Completed tertiary education	80 (58)	24 (42)	56 (68)	0.014*^$
A level or equivalent	39 (28)	23 (40)	16 (19)
GCSE or equivalent	20 (14)	10 (18)	10 (12)
Current illicit drug use, n (%)	31 (22)	11 (19)	20 (24)	0.502
History of illicit drug use, n (%)	81 (58)	29 (51)	52 (63)	0.166
Current use of ART, n (%)	135 (96)	55 (96)	80 (96)	0.974
Exposure to d-type NRTI, n (%)	54 (39)	21 (37)	33 (40)	0.904
Serum triglyceride mmol/L (sd)	2.11 (1.54)	2.61 (1.79)	1.81 (1.29)	0.010*
Diabetes diagnosis, n (%)	10 (7)	6 (11)	4 (5)	0.316
Previous chemotherapy, n (%)	13 (9)	6 (11)	7 (8)	0.675

Presented as mean (sd) unless stated. *indicates significance. ^##more participants were employed in the no cognitive impairment group (p = 0.009) and less were unemployed (p = 0.034); ^$more participants had completed tertiary education in the no cognitive impairment group (p = 0.002).

Table 2. A comparison of pain diagnoses and treatment between participants with and without cognitive impairment.

	Total cohort n = 140	Cognitive impairment n = 57	No cognitive impairment n = 83	p-value
Number of painful sites, median (IQR)	5 (1–11)	6 (1.5–11)	4 (1–11)	0.234
Number of participants with chronic pain, n (%)	73 (52)	38 (67)	35 (42)	0.004*
Number participants with painful HIV-SN, n (%)	52 (37)	29 (51)	23 (28)	0.005*
Number participants with painless HIV-SN, n (%)	33 (24)	8 (14)	25 (30)	0.028
Number of non HIV-SN chronic pain diagnoses, median (IQR)	1 (0–2)	1 (0–2)	1 (0–2)	0.597
Number of participants with non HIV-SN chronic pain diagnosis, n (%)	104 (74)	41 (72)	62 (75)	0.715
Participants reporting current strong opiate use, n (%)	23 (16)	12 (21)	11 (13)	0.221
Participants reporting current weak opiate use, n (%)	20 (14)	11 (19)	9 (11)	0.160

HIV-SN = HIV-associated sensory neuropathy * indicates significance after correction for multiple comparisons.

Table 3. Comparison of pain symptoms and interference in participants with chronic pain between those with and without cognitive impairment.

	Total cohort n = 73	Cognitive impairment n = 38	No cognitive impairment n = 35	p-value
NPSI Burning	5.0 (1.0–8.0)	6.0 (4.0–9.0)	4.0 (0–7.0)	0.009
NPSI Pressure	4.0 (1.25–6.8)	4.5 (2.5–7.3)	2.75 (0–5.5)	0.067
NPSI Paroxysmal	4.5 (1.3–73)	5.0 (2.5–8.0)	3.5 (0–6.5)	0.034
NPSI Evoked	3.3 (1.7–6.0)	4.7 (2.3–6.7)	2.3 (0.5–5.2)	0.100
NPSI Paraesthesia	6.0 (2.3–7.8)	6.0 (3.5–8.0)	4.3 (1.1–7.0)	0.095
NPSI Intensity total	4.2 (2.6–6.1)	4.9 (3.6–7.1)	3.0 (1.9–5.2)	0.001*
BPI Severity Score	5.3 (3.8–6.9)	5.5 (4.8–7.1)	4.8 (2.0–6.3)	0.025
BPI Interference Score	4.5 (3.0–5.6)	4.5 (3.3–5.7)	4.4 (2.2–5.6)	0.474

Data presented as median (IQR). NPSI = Neuropathic Pain Symptom Inventory; BPI = Brief Pain Inventory. *indicates significance after controlling for multiple comparisons.

Figure 1. Comparison of cognitive domains between participants with and without chronic pain. *indicates a significant difference after correction for multiple comparisons. GML = Groton Maze Learning (function); IDN = Identification Test (attention); DET = Detection Test (psychomotor function); ISL = International Shopping List (verbal learning); ISLR = International shopping list delayed recall test (verbal memory); OCL = One card leaning(visual learning); ONB = One card back test (working memory); SECT = Social and emotional cognition test (emotional recognition); Global = Global T-score.

Figure 2. Comparison of cognitive domain scores between those with painful and painless HIV-SN, and those without HIV-SN. *indicates significance after correction for multiple comparisons. GML = Groton Maze Learning (function); IDN = Identification Test (attention); DET = Detection Test (psychomotor function); ISL = International Shopping List (verbal learning); ISLR = International shopping list delayed recall test (verbal memory); OCL = One card leaning(visual learning); ONB = One card back test (working memory); SECT = Social and emotional cognition test (emotional recognition); Global = Global T-score.

Table 4. Comparison of psychological and quality life measures between those with and without cognitive impairment (with results reported separately for those with and without chronic pain).

	Total cohort			Chronic pain			No chronic pain
	Cognitive impairment	No cognitive impairment	p-value	Cognitive impairment	No cognitive impairment	p-value	Cognitive impairment	No cognitive impairment	p-value
DAPOS Depression score	12.3 (5.4)	10.6 (5.1)	0.081	12.6 (5.4)	13.1 (4.9)	0.657	11.6 (5.6)	8.6 (4.2)	0.035
DAPOS Anxiety Score	7.8 (4.0)	6.1 (3.3)	0.010*	8.7 (4.0)	7.0 (3.8)	0.075	5.9 (3.7)	5.4 (2.8)	0.567
DAPOS Positive Outlook Score	8.5 (3.4)	10.3 (2.8)	0.002*	7.6 (3.3)	9.3 (2.3)	0.015*	10.5 (3.4)	11.1 (3.0)	0.519
SF-36 General Health Score	32.6 (23.3)	45.3 (28.1)	0.007*	23.9 (16.4)	26.9 (20.1)	0.513	51.5 (25.4)	59.8 (24.9)	0.278

Data presented as mean (sd). * indicates significance after correction for multiple comparisons. DAPOS = Depression Anxiety and Positive Outlook Scale; SF-36 = 36 Item Short Form Survey for health-related quality of life.