Effect of blood pressure variability on hypertensive retinopathy

Figures & data

Figure 1. Optical coherence tomography angiography 6×6mm scan image centered on the optic disc. The diameters of the three concentric circles are 1, 3, and 6mm. The measurement tool (AngioPlex software, version 10.0; Carl Zeiss Meditec) provided (a) vessel density and (b) perfusion density measurements in individual subfields. The bold box shows the automatic quantitative measurements for an average of the inner ring, outer ring, and full area.

Table 1. Demographics and clinical features of the study subjects.

	Low ARV group (n = 55)	High ARV group (n = 55)	Control group (n = 60)	P-value
Male	29(52.7%)	27(49.1%)	29(51.7%)	0.883
Age(year)	51.71 ± 11.76	58.89 ± 10.84	54.87 ± 13.91	0.037*
BMI(kg/m^2)	25.81 ± 4.31	24.95 ± 4.13	23.79 ± 3.00	0.025*
History of smoking	24(43.6%)	23(41.8%)	15(25.0%)	0.070
Duration of hypertension (years)	8.41 ± 7.44	8.86 ± 7.86	0	0.001*
BCVA（logMAR）	0.17 ± 0.14	0.20 ± 0.12	0.20 ± 0.12	0.388
IOP（mmHg）	15.82 ± 1.50	15.89 ± 1.41	15.97 ± 1.43	0.860
K-W-B classification （0/I/II/III/IV）	55 (0/28/16/10/1)	55 (0/24/20/9/2)	60 (0)	0.001*

*p＜0.05 ARV=average real variability; BCVA = best corrected visual acuity; log MAR = logarithm of the minimum angle of resolution; IOP= Intraocular pressure.

Table 2. ABPM parameters of all patients and controls.

	Low ARV group (n = 55)	High ARV group (n = 55)	Control group (n = 60)	P-value	P-value*	P-value**	P-value***
SBP-ARV	9.01 ± 1.58	14.14 ± 2.46	11.37 ± 3.49	0.001	0.001	0.001	0.001
DBP-ARV	8.85 ± 2.20	11.05 ± 2.95	9.08 ± 1.99	0.001	0.001	1.000	0.001
24hSBP	134.95 ± 13.21	140.56 ± 19.87	113.95 ± 7.78	0.001	0.124	0.001	0.001
24 h DBP	87.71 ± 12.62	85.20 ± 16.00	72.05 ± 7.35	0.001	0.869	0.001	0.001
24hSBPSD	13.62 ± 4.09	16.98 ± 4.16	12.29 ± 2.79	0.001	0.001	0.168	0.001
24hSBPCV	10.09 ± 2.73	12.08 ± 2.33	10.83 ± 2.22	0.001	0.001	0.311	0.020
24hDBPSD	10.45 ± 3.18	11.96 ± 3.87	9.87 ± 2.32	0.002	0.041	0.966	0.002
24hDBPCV	11.96 ± 3.29	14.07 ± 3.98	13.52 ± 2.86	0.004	0.004	0.042	1.000
Day SBP	135.58 ± 13.09	141.42 ± 21.25	115.05 ± 8.95	0.001	0.135	0.001	0.001
Day DBP	88.71 ± 12.61	85.29 ± 15.49	73.57 ± 8.16	0.001	0.445	0.001	0.001
Day SBPSD	13.53 ± 4.92	16.91 ± 4.85	16.55 ± 17.94	0.229	0.361	0.468	1.000
Day SBPCV	9.96 ± 3.30	11.88 ± 2.50	11.88 ± 2.50	0.002	0.001	0.297	0.127
Day DBPSD	10.45 ± 3.25	11.91 ± 4.39	9.77 ± 2.91	0.006	0.098	0.928	0.005
Day DBPCV	11.83 ± 3.42	13.92 ± 4.35	13.16 ± 3.38	0.013	0.011	0.175	0.821
Night SBP	132.35 ± 16.14	137.96 ± 18.25	111.85 ± 8.13	0.001	0.139	0.001	0.001
Night DBP	84.35 ± 13.59	82.20 ± 13.52	68.27 ± 7.52	0.001	1.000	0.001	0.001
Night SBPSD	12.10 ± 6.23	14.98 ± 4.89	10.47 ± 3.97	0.001	0.010	0.268	0.001
Night SBPCV	9.25 ± 5.15	11.01 ± 3.71	9.43 ± 3.40	0.052	0.085	1.000	0.129
Night DBPSD	9.66 ± 4.46	9.96 ± 2.94	8.43 ± 3.11	0.051	1.000	0.196	0.067
Night DBPCV	11.62 ± 5.52	12.32 ± 3.97	12.34 ± 4.23	0.644	1.000	1.000	1.000

All data are shown as mean ± standard deviation.

ARV=average real variability; SBP-ARV= systolic average real variability; DBP-ARV= diastolic average real variability; SBP=systolic blood pressure; DBP=diastolic blood pressure; SBPSD= the standard deviation of systolic blood pressure; DBPSD=the standard deviation of diastolic blood pressure; SBPCV= the coefficient of variation of systolic blood pressure; DBPCV= the coefficient of variation of diastolic blood pressure.

The p-value was obtained using one-way analysis of variance.

*The p-value was obtained using post hoc tests (Bonferroni) between the Low ARV group and the High ARV group.

**The p-value was obtained using post hoc tests (Bonferroni) between the Low ARV group and the normal control group.

***The p-value was obtained using post hoc tests (Bonferroni) between the High ARV group and the normal control group.

Table 3. Comparison of RNFL thickness, ILM-RPE mean volume thickness, VD and PD among groups.

	Low ARV group (n = 55)	High ARV group (n = 55)	Control group (n = 60)	P-value	P-value*	P-value**	P-value***
RNFL thickness (um)	92.21 ± 10.28	87.91 ± 13.35	93.80 ± 7.97	0.011	0.108	1.000	0.011
ILM-RPE Average volume thickness (μm)	275.98 ± 12.77	270.78 ± 11.39	281.28 ± 9.44	0.001	0.049	0.037	0.001
ILM-RPE volume (mm3)	9.89 ± 0.41	9.70 ± 0.55	10.10 ± 0.38	0.001	0.093	0.047	0.001
ILM-RPE Central subarea (mm3)	244.87 ± 21.21	247.89 ± 21.95	255.80 ± 17.64	0.013	1.000	0.013	0.115
VD full area	12.94 ± 2.40	10.46 ± 2.35	14.62 ± 2.04	0.001	0.001	0.001	0.001
Center of VD inner ring	2.55 ± 1.82	1.57 ± 1.30	4.28 ± 2.98	0.001	0.059	0.001	0.001
VD Inner ring average	11.28 ± 3.35	8.64 ± 2.98	14.06 ± 3.16	0.001	0.001	0.001	0.001
VD Outer ring average	14.07 ± 2.40	11.92 ± 2.66	15.18 ± 2.02	0.001	0.001	0.039	0.001
PD full area	0.303 ± 0.057	0.252 ± 0.067	0.350 ± 0.056	0.001	0.001	0.001	0.001
Center of PD inner ring	0.071 ± 0.049	0.045 ± 0.034	0.105 ± 0.082	0.001	0.062	0.007	0.001
PD Inner ring average	0.267 ± 0.066	0.206 ± 0.070	0.332 ± 0.092	0.001	0.001	0.001	0.001
PD Outer ring average	0.327 ± 0.056	0.284 ± 0.065	0.365 ± 0.053	0.001	0.001	0.002	0.001

All data are shown as mean ± standard deviation.

RNFL=retinal nerve fiber layer thickness; ILM-RPE=Internal limiting membrane – retinal pigment epithelium; VD=vessel density; PD=perfusion density; ARV=average real variability.

The p-value was obtained using one-way analysis of variance.

*The p-value was obtained using post hoc tests (Bonferroni) between the Low ARV group and the High ARV group.

**The p-value was obtained using post hoc tests (Bonferroni) between the Low ARV group and the normal control group.

***The p-value was obtained using post hoc tests (Bonferroni) between the High ARV group and the normal control group.

Table 4. Multivariate regression analysis of OCT parameters and OCTA parameters with baseline indexes and blood pressure variability.

	β (95%CI)	p-value	R^2
RNFL
Duration of hypertension	−0.678(−0.945, −0.411)	0.001*	0.743
Age	−0.381(−0.564, −0.198)	0.001*
24hDBPSD	−0.707(−1.138, −0.276)	0.002*
ILM-RPE
Duration of hypertension	−0.867(−1.115, −0.619)	0.001*	0.607
24hDBPCV	−0.759(−1.258, −0.260)	0.003*
VD
Duration of hypertension	−0.135(−0.190, −0.080)	0.001*	0.724
SBP-ARV	−0.259(−0.377, −0.140)	0.001*
Day SBP	−0.034(−0.055, −0.012)	0.003*
IOP	0.329(0.073, 0.584)	0.012*
BCVA(logMAR)	−3.324(−6.527, −0.122)	0.042*
PD
Duration of hypertension	−0.005(−0.006, −0.004)	0.001*	0.770
SBP-ARV	−0.006(−0.009, −0.003)	0.001*
Day-SBP	−0.001(−0.001, 0.001)	0.001*
IOP	0.007(0.001, 0.013)	0.020*

RNFL=retinal nerve fiber layer thickness; ILM-RPE=Internal limiting membrane – retinal pigment epithelium; VD=vessel density; PD=perfusion density; BCVA = best corrected visual acuity; log MAR = logarithm of the minimum angle of resolution; IOP= Intraocular pressure.

SBP-ARV= systolic average real variability; SBP=systolic blood pressure; DBPSD=the standard deviation of diastolic blood pressure; DBPCV= the coefficient of variation of diastolic blood pressure.

*p＜0.05.