Chronic Kidney Disease Modifies The Relationship Between Body Fat Distribution and Blood Pressure: A Cross-Sectional Analysis

Figures & data

Table 1 Clinical Characteristics of the Study Population Overall and by CKD Status

Variables	Total Sample (n=1621)	Without CKD (n=1525)	CKD (n=96)	p-value
	DXA Sub-Sample (n=152)	Without CKD (n=141)	CKD (n=11)
Age (years)	51 (37–61)	49 (36–59)	68 (62–73.5)	<0.0001
Gender (n,% male)	406 (25.1)	378 (25.4)	19 (19.8)	0.221
Body Fat Distribution
Weight (kg)	71.8 (59.2–85.3)	71.5 (59.0–85.2)	74.0 (64.6–87.0)	0.120
Waist circumference (cm)	91.5 (78.1–103.2)	90.8 (77.5–102.8)	99.0 (89.0–105.8)	<0.0001
Body mass index (kg/m^2)	28.3 (22.8–34.1)	28.2 (22.5–34.1)	30.4 (26.0–36.1)	0.0035
Fat mass (kg)	30.6 (22.5–38.2)	30.3 (22.1–36.9)	31.0 (25.9–42.7)	0.365
Fat mass (%)	42.1 (34.5–46.7)	42.3 (33.9–46.5)	41.0 (38.8–48.1)	0.477
Trunk fat mass (kg)	16.0 (11.5–20.7)	16.0 (11.2–20.4)	17.7 (13.3–21.8)	0.293
Trunk fat mass (%FM)	52.1 (48.1–56.1)	52.0 (48.1–56.1)	54.3 (48.7–56.6)	0.534
Leg fat mass (kg)	10.2 (7.6–13.9)	10.1 (7.4–13.9)	11.2 (9.1–13.7)	0.488
Leg fat mass (%FM)	35.6 (31.0–40.2)	35.8 (31.2–40.2)	34.6 (31.0–39.4)	0.466
Arm fat mass (kg)	3.7 (2.5–4.8)	3.7 (2.5–4.8)	3.9 (3.4–5.1)	0.266
Arm fat mass (%FM)	11.9 (10.8–13.4)	11.9 (10.7–13.5)	11.9 (11.1–13.7)	0.756
Visceral adipose tissue (cm^2)	180.8 ± 81.8	174.9 ± 79.1	228.4 ± 89.8	0.0052
Subcutaneous adipose tissue (cm^2)	421.7 ± 158.4	418.1 ± 160.4	450.2 ± 142.4	0.217
Blood Pressure Measures
Systolic blood pressure (mmHg)	125.0 (111.0–141.0)	125.0 (110.0–140.0)	141.0 (118.0–162.0)	<0.0001
Diastolic blood pressure (mmHg)	81.0 (72.0–90.0)	81.0 (72.0–90.0)	80.5 (74.0–93.0)	0.315
Pulse pressure (mmHg)	44.0 (34.0–55.0)	43.0 (34.0–54.0)	55.0 (42.0–72.0)	<0.0001
Mean arterial pressure (mmHg)	95.7 (86.0–106.3)	95.7 (85.7–105.7)	100.3 (92.3–114.6)	0.0005
Biochemical Measures
Fasting blood glucose (mmol/l)	5.0 (4.6–5.7)	5.0 (4.6–5.6)	5.3 (5.0–7.1)	<0.0001
2-hour glucose (mmol/l)	6.0 (4.9–7.6)	6.0 (4.8–7.5)	7.4 (6.1–9.2)	<0.0001
Fasting insulin (IU/l)	6.7 (4.2–11.0)	6.7 (4.2–10.9)	7.6 (5.1–12.1)	0.033
2-hour insulin (IU/l)	37.9 (20.5–70.9)	37.3 (19.8–69.7)	58.8 (29.5–105.2)	0.0003
HOMA-IR	1.6 (0.9–2.8)	1.5 (0.9–2.8)	2.1 (1.1–3.5)	0.0012
HbA1c (%)	5.8 (5.4–6.3)	5.7 (5.4–6.2)	6.2 (5.9–7.1)	<0.0001
Creatinine (µmol/l)	59.0 (52.0–70.0)	59.0 (51.0–68.0)	105.5 (89.0–137.5)	<0.0001
eGFR (mL/min/1.73m^2)	102.5 (85.0–119.4)	104.4 (88.4–121.5)	48.5 (34.1–56.2)	<0.0001
Co-morbidities
Hypertension (n, %)	622 (38.4)	561 (36.8)	61 (63.5)	<0.0001
BMI categories (n, %)				0.008
Normal weight	557 (34.4)	538 (35.3)	19 (19.8)
Overweight	372 (23.0)	345 (22.6)	27 (28.1)
Obese	692 (42.7)	642 (42.1)	50 (52.1)
Glucose tolerance categories (n, %)				<0.0001
Normal glucose tolerance	1048 (64.7)	1009 (66.2)	39 (40.6)
IFG/IGT	281 (17.3)	262 (17.2)	19 (19.8)
Type 2 diabetes	277 (17.1)	240 (15.7)	37 (38.5)

Note: Data presented as median (25th-75th percentile), mean ±  SD and percentages.

Abbreviations: CKD, chronic kidney disease; BMI, body mass index; HOMA-IR, homeostatic model assessment-insulin resistance; HbA1c, glycated haemoglobin; eGFR, estimated glomerular filtration rate; IFG, impaired fasting glucose; IGT, impaired glucose tolerance.

Table 2 Correlations Between Blood Pressure and Measures of Body Fat Distribution

	Total		Without CKD		CKD
	rho	p-value	rho	p-value	rho	p-value
SBP
Body mass index (kg/m^2)	0.18	<0.0001	0.19	<0.0001	−0.12	0.231
Waist circumference (cm)	0.23	0.0001	0.24	<0.0001	−0.24	0.235
Fat mass (kg)	0.18	0.0236	0.22	0.0100	−0.19	0.459
Trunk fat mass (kg)	0.20	0.0131	0.23	0.0066	−0.13	0.619
Leg fat mass (kg)	0.13	0.101	0.17	0.053	−0.21	0.422
Arm fat mass (kg)	0.21	0.0084	0.25	0.0036	−0.09	0.740
Visceral adipose tissue (cm^2)	0.31	0.0001	0.34	0.0001	0.03	0.896
Subcutaneous adipose tissue (cm^2)	0.17	0.0343	0.16	0.057	−0.11	0.666
DBP
Body mass index (kg/m^2)	0.21	<0.0001	0.22	<0.0001	0.13	0.216
Waist circumference (cm)	0.23	<0.0001	0.23	<0.0001	0.09	0.379
Fat mass (kg)	0.18	0.0298	0.20	0.0189	0.10	0.704
Trunk fat mass (kg)	0.21	0.0106	0.23	0.0066	0.14	0.605
Leg fat mass (kg)	0.10	0.217	0.13	0.145	−0.01	0.983
Arm fat mass (kg)	0.21	0.0106	0.23	0.0068	0.16	0.529
Visceral adipose tissue (cm^2)	0.22	0.0053	0.23	0.0075	0.31	0.229
Subcutaneous adipose tissue (cm^2)	0.19	0.0161	0.22	0.0098	0.18	0.485
PP
Body mass index (kg/m^2)	0.08	0.0026	0.08	0.0036	−0.21	0.0349
Waist circumference (cm)	0.13	<0.0001	0.13	<0.0001	−0.19	0.057
Fat mass (kg)	0.14	0.079	0.16	0.062	−0.16	0.547
Trunk fat mass (kg)	0.15	0.068	0.16	0.068	−0.09	0.726
Leg fat mass (kg)	0.12	0.152	0.14	0.106	−0.16	0.549
Arm fat mass (kg)	0.16	0.0535	0.18	0.050	−0.03	0.907
Visceral adipose tissue (cm^2)	0.30	0.0002	0.30	0.0004	0.02	0.929
Subcutaneous adipose tissue (cm^2)	0.08	0.338	0.08	0.344	−0.09	0.743
MAP
Body mass index (kg/m^2)	0.21	<0.0001	0.21	<0.0001	−0.01	0.901
Waist circumference (cm)	0.24	<0.0001	0.25	<0.0001	−0.00	0.098
Fat mass (kg)	0.19	0.0207	0.22	0.0089	−0.10	0.715
Trunk fat mass (kg)	0.21	0.0087	0.25	0.0040	−0.05	0.837
Leg fat mass (kg)	0.12	0.127	0.16	0.058	−0.16	0.531
Arm fat mass (kg)	0.22	0.0062	0.26	0.0024	−0.00	0.987
Visceral adipose tissue (cm^2)	0.27	0.0008	0.29	0.0006	0.12	0.653
Subcutaneous adipose tissue (cm^2)	0.19	0.0217	0.21	0.0158	−0.01	0.974

Note: Data is presented as Spearman correlation coefficients (r) and p-value.

Abbreviation: CKD, chronic kidney disease.

Figure 1 Adjusted association between blood pressure indices and anthropometric-derived measures of body fat distribution, dichotomized by CKD status. Presentation of graphs are as follows: Adjusted association between, (A) systolic blood pressure and body mass index, (B) pulse pressure and body mass index, (C) systolic blood pressure and waist circumference and (D) pulse pressure and waist circumference. Data is presented as (1) linear predictive margins for those with CKD (dashed line) and those without CKD (solid line) with 95% CI and (2) the average marginal effect (dy/dx), 95% CI and p-value indicating the association between blood pressure and measures of body fat distribution, for those with and without CKD.

Figure 2 Adjusted association between blood pressure indices and DXA-derived measures of body fat distribution, dichotomized by CKD status. Presentation of graphs are as follows: Adjusted association between, (A) systolic blood pressure and leg fat mass, (B) pulse pressure and leg fat mass. Data is presented as (1) linear predictive margins for those with CKD (dashed line) and those without CKD (solid line) with 95% CI and (2) the average marginal effect (dy/dx), 95% CI and p-value indicating the association between blood pressure and measures of body fat distribution, for those with and without CKD.

Table 3 Regression Coefficients from Robust Multiple Linear Models for the Prediction of Blood Pressure Level by Anthropometric-Derived Measures of Body Fat Distribution, Accounting for Potential Effects of Age and Gender

	SBP			DBP			PP			MAP
	β	95% CI	p	β	95% CI	p	β	95% CI	p	β	95% CI	p
Age	0.69	0.62 to 0.76	<0.0001	0.18	0.13 to 0.22	<0.0001	0.47	0.43 to 0.52	<0.0001	0.36	0.31 to 0.41	<0.0001
Gender	−3.14	−5.57 to −0.71	0.011	0.54	−1.04 to 2.12	0.504	−3.65	−5.29 to −2.01	<0.0001	−0.50	−2.24 to 1.24	0.572
BMI	0.27	0.13 to 0.41	<0.0001	0.27	0.18 to 0.36	<0.0001	0.03	−0.07 to 0.12	0.584	0.25	0.16 to 0.35	<0.0001
CKD	15.60	−2.31 to 33.50	0.088	−7.76	−19.41 to 3.89	0.192	19.2	7.13 to 31.27	0.002	−2.61	−15.43 to 10.21	0.690
CKDxBMI	−0.47	−1.03 to 0.09	0.098	0.14	−0.22 to 0.51	0.433	−0.49	−0.86 to −0.11	0.011	0.02	−0.38 to 0.42	0.928
Adjusted R^2	0.20			0.06			0.19			0.13
Age	0.68	0.61 to 0.75	<0.0001	0.16	0.12 to 0.21	<0.0001	0.48	0.43 to 0.53	<0.0001	0.34	0.29 to 0.39	<0.0001
Gender	−2.51	−4.86 to −0.15	0.037	1.09	−0.44 to 2.63	0.161	−3.48	−5.06 to −1.90	<0.0001	0.07	−1.62 to 1.76	0.936
WC	0.13	0.06 to 0.19	<0.0001	0.13	0.09 to 0.17	<0.0001	0.00	−0.05 to 0.04	0.822	0.12	0.08 to 0.17	<0.0001
CKD	32.11	7.89 to 56.33	0.009	−1.50	−17.27 to 14.27	0.852	30.36	14.06 to 46.66	<0.0001	6.16	−11.22 to 23.53	0.487
CKDxWC	−0.32	−0.56 to −0.08	0.010	−0.02	−0.18 to 0.14	0.812	−0.27	−0.43 to −0.10	0.001	−0.08	−0.26 to 0.09	0.337
Adjusted R^2	0.20			0.07			0.19			0.13

Notes: Data are presented as β-coefficients, 95% confidence intervals (CI) and p-values (p) for each body distribution variable, as well as R² for each model; BMI in kg/m²; WC in cm.

Abbreviations: SBP, systolic blood pressure; DBP, diastolic blood pressure; PP, pulse pressure; MAP, mean arterial pressure; BMI, body mass index; WC, waist-circumference; CKD, chronic kidney disease.

Table 4 Regression Coefficients from Robust Multiple Linear Models for the Prediction of Blood Pressure by DXA-Derived Measures of Body Fat Distribution, Accounting for Potential Effects of Age and Gender

	SBP			DBP			PP			MAP
	β	95% CI	p	β	95% CI	p	β	95% CI	p	β	95% CI	p
Age	0.84	0.64 to 1.04	<0.0001	0.18	0.04 to 0.31	0.011	0.61	0.46 to 0.76	<0.0001	0.40	0.26 to 0.54	<0.0001
Gender	1.17	−6.73 to 9.07	0.770	1.49	−3.91 to 6.89	0.587	−0.27	−6.17 to 5.63	0.927	1.49	−4.20 to 7.18	0.606
FM	0.05	−0.20 to 0.31	0.670	0.10	−0.07 to 0.27	0.278	−0.01	−0.20 to 0.18	0.885	0.08	−0.10 to 0.26	0.398
CKD	6.89	−16.8 to 30.57	0.567	−5.37	−21.57 to 10.82	0.513	9.84	−7.86 to 27.53	0.274	−1.89	−18.95 to 15.17	0.827
CKDxFM	−0.40	−1.04 to 0.25	0.227	−0.07	−0.52 to 0.37	0.746	−0.28	−0.76 to 0.20	0.253	−0.16	−0.63 to 0.30	0.493
Adjusted R^2	0.31			0.08			0.31			0.18
Age	0.84	0.64 to 1.04	<0.0001	0.17	0.03 to 0.30	0.016	0.62	0.47 to 0.77	<0.0001	0.39	0.25 to 0.53	<0.0001
Gender	0.90	−6.74 to 8.53	0.816	1.28	−3.84 to 6.40	0.623	−0.29	−6.01 to 5.42	0.919	1.26	−4.20 to 6.73	0.648
TFM	0.13	−0.34 to 0.60	0.592	0.25	−0.07 to 0.57	0.123	−0.06	−0.42 to 0.29	0.724	0.20	−0.13 to 0.54	0.235
CKD	2.89	−20.26 to 26.03	0.806	−5.72	−21.24 to 9.80	0.468	5.48	−11.84 to 22.80	0.533	−3.32	−19.88 to 13.24	0.693
CKDxTFM	−0.54	−1.73 to 0.65	0.369	−0.12	−0.91 to 0.68	0.770	−0.30	−1.19 to 0.58	0.500	−0.23	−1.08 to 0.62	0.589
Adjusted R^2	0.31			0.09			0.30			0.19
Age	0.84	0.65 to 1.04	<0.0001	0.20	0.06 to 0.33	0.004	0.61	0.46 to 0.75	<0.0001	0.41	0.27 to 0.56	<0.0001
Gender	2.09	−5.97 to 10.14	0.609	2.80	−2.67 to 8.26	0.313	−0.42	−6.38 to 5.54	0.890	2.68	−3.16 to 8.52	0.365
LFM	0.06	−0.58 to 0.71	0.854	0.04	−0.40 to 0.48	0.857	0.06	−0.42 to 0.53	0.815	0.03	−0.43 to 0.50	0.888
CKD	15.01	−7.99 to 38.00	0.199	−2.51	−18.10 to 13.08	0.751	15.31	−1.71 to 32.33	0.078	2.17	−14.49 to 18.83	0.797
CKDxLFM	−1.81	−3.61 to 0.00	0.050	−0.42	−1.64 to 0.81	0.503	−1.27	−2.60 to 0.07	0.064	−0.80	−2.11 to 0.51	0.232
Adjusted R^2	0.32			0.08			0.31			0.18
Age	0.84	0.64 to 1.04	<0.0001	0.17	0.03 to 0.31	0.014	0.62	0.47 to 0.77	<0.0001	0.40	0.25 to 0.54	<0.0001
Gender	1.14	−6.87 to 9.14	0.779	1.09	−4.40 to 6.57	0.696	0.05	−5.93 to 6.04	0.986	1.10	−4.66 to 6.87	0.706
AFM	0.38	−1.50 to 2.26	0.690	0.83	−0.45 to 2.12	0.203	−0.30	−1.70 to 1.11	0.677	0.70	−0.65 to 2.05	0.307
CKD	−0.17	−20.83 to 20.50	0.987	−7.12	−21.28 to 7.03	0.322	4.08	−11.37 to 19.52	0.603	−5.28	−20.17 to 9.61	0.485
CKDxAFM	−1.65	−6.07 to 2.77	0.462	−0.21	−3.23 to 2.82	0.893	−1.00	−4.31 to 2.30	0.550	−0.58	−3.77 to 2.60	0.716
Adjusted R^2	0.31			0.08			0.30			0.18
Age	0.84	0.62 to 1.06	<0.0001	0.13	−0.01 to 0.27	0.078	0.62	0.46 to 0.79	<0.0001	0.37	0.21 to 0.53	<0.0001
Gender	1.74	−5.51 to 8.99	0.636	2.68	−2.13 to 7.49	0.273	−0.53	−5.93 to 4.88	0.848	2.58	−2.58 to 7.75	0.325
VAT	0.01	−0.04 to 0.05	0.788	0.02	−0.00 to 0.05	0.102	−0.01	−0.04 to 0.02	0.674	0.02	−0.01 to 0.05	0.280
CKD	−12.38	−36.94 to 12.17	0.321	−12.10	−28.39 to 4.20	0.145	−3.12	−21.44 to 15.21	0.737	−12.22	−29.73 to 5.28	0.170
CKDxVAT	0.02	−0.08 to 0.12	0.683	0.02	−0.05 to 0.09	0.588	0.01	−0.07 to 0.09	0.785	0.02	−0.05 to 0.09	0.562
Adjusted R^2	0.31			0.10			0.31			0.19
Age	0.85	0.65 to 1.05	<0.0001	0.17	0.03 to 0.30	0.014	0.62	0.47 to 0.77	<0.0001	0.40	0.25 to 0.54	<0.0001
Gender	0.91	−7.25 to 9.06	0.826	0.54	−4.88 to 5.96	0.843	0.16	−5.91 to 6.23	0.958	0.82	−5.01 to 6.65	0.782
SAT	0.00	−0.02 to 0.02	0.725	0.01	−0.00 to 0.03	0.100	−0.00	−0.02 to 0.01	0.561	0.01	−0.01 to 0.02	0.256
CKD	−1.97	−31.34 to 27.41	0.895	−6.31	−25.83 to 13.21	0.524	1.95	−19.92 to 23.82	0.860	−5.23	−26.24 to 15.79	0.624
CKDxSAT	−0.01	−0.07 to 0.05	0.698	−0.00	−0.04 to 0.04	0.884	−0.01	−0.05 to 0.04	0.807	−0.01	−0.05 to 0.04	0.819
Adjusted R^2	0.31			0.09			0.30			0.18

Notes: Data are presented as β-coefficients, 95% confidence intervals (CI) and p-values (p) for each body distribution variable, as well as R² for each model; All fat mass measures in kg.

Abbreviations: SBP, systolic blood pressure; DBP, diastolic blood pressure; PP, pulse pressure; MAP, mean arterial pressure; BMI, body mass index; WC, waist circumference; CKD, chronic kidney disease; FM, fat mass; TFM, trunk fat mass; LFM, leg fat mass; AFM, arm fat mass; VAT, visceral adipose tissue; SAT, subcutaneous adipose tissue.