Racial Differences and Contributory Cardiovascular and Non-Cardiovascular Risk Factors Towards Chronic Kidney Disease Progression

Figures & data

Table 1 Characteristics of CARDIA Study Participants According to Race

	Black Participants		White Participants		P-value
	N	Mean±SD	N	Mean±SD
Age at Year 10	2175	34.3±3.8	2207	35.6±3.4	0.02
Sex (Female), n (%)	2175	1245 (57.2)	2207	1171 (53.1)	0.005
Maximal educational level	2175	14.7±2.4	2207	16.3±2.6	<0.001
eGFR (mL/min/1.73 m^2) at Year 10	1848	102.8±19.1	1975	108.3±12.6	<0.001
UACR (mg/g) at Year 10	1671	29.5±248.3	1813	10.7±119.5	0.004
Non-traditional risk factors
FVC (L)
Year 10	1786	3.8±0.9	1918	4.7±1.0	<0.001
Year 30	1470	3.1±0.8	1639	3.9±0.9	<0.001
Year 30- Year 10	1248	–0.7±0.4	1472	–0.7±0.4	0.76
Plasma GlycA (μmol/L)
Year 7	1727	406.1±69.5	1952	383.4±64.8	<0.001
ln(serum hsCRP) (ln(nmol/L))
Year 7	1742	10.5±7.6	1964	8.6±6.7	<0.001
Year 25	1621	12.4±7.6	1845	8.6±5.7	<0.001
Year 25-Year 7	1343	1.9±7.6	1678	0.4±6.7	<0.001
Serum urate (µmol/L)
Year 0	2139	303.4±83.3	2191	321.2±83.3	<0.001
Year 20	1401	345.0±95.2	1736	339.0±83.3	0.02
Year 20-Year 0	1389	47.6±77.3	1726	17.8±65.4	<0.001
Sum of 4 serum carotenoids (µmol/L)
Year 7	1672	0.84±0.43	1887	1.01±0.56	<0.001
Year 20	1219	0.82±0.46	1509	1.00±0.62	<0.001
Year 20-Year 7	992	–0.02±0.42	1338	0.01±0.53	0.14
Conventional cardiovascular risk factors
Pack-year of smoking ≥10, n (%)
Year 10	2175	280 (12.9)	2207	391 (17.7)	<0.001
Year 30	2175	519 (23.9)	2207	480 (21.8)	0.10
Year 30-Year 10	2175	239 (11.0)	2207	89 (4.0)	<0.001
Hypertension (≥140/90 mm Hg/antihypertensive medications), n (%)
Year 10	2175	364 (16.7)	2207	162 (7.3)	<0.001
Year 30	2175	1214 (55.8)	2207	682 (30.9)	<0.001
Year 30-Year 10	2175	850 (39.1)	2207	520 (23.6)	<0.001
Diabetes (serum glucose ≥6.99 mmol/L, 2-hr glucose ≥11.1 mmol/L, or Hb1Ac ≥0.07 fraction/ antidiabetic medications), n (%)
Year 10	2175	69 (3.2)	2207	44 (2.0)	0.01
Year 30	2175	446 (20.5)	2207	231 (10.5)	<0.001
Year 30-Year 10	2175	377 (17.3)	2207	187 (8.5)	<0.001
High serum triglycerides (≥1.69 mmol/L), n (%)
Year 10	2175	306 (14.1)	2207	537 (24.3)	<0.001
Year 30	2175	626 (28.8)	2207	943 (42.7)	<0.001
Year 30-Year 10	2175	320 (14.7)	2207	406 (18.4)	0.001
Low HDL-C (serum <1.29 mmol/L for female and <1.04 mmol/L for male), n (%)
Year 10	2175	1211 (55.7)	2207	1244 (56.4)	0.65
Year 30	2175	1377 (63.3)	2207	1389 (62.9)	0.80
Year 30-Year 10	2175	320 (14.7)	2207	406 (18.4)	0.001
Obesity (≥30 kg/m^2), n (%)
Year 10	2175	834 (38.3)	2207	427 (19.4)	<0.001
Year 30	2175	1338 (61.5)	2207	892 (40.4)	<0.001
Year 30-Year 10	2175	504 (23.2)	2207	465 (21.1)	0.09

Abbreviations: FVC, forced vital capacity; HDL-C, high-density lipoprotein cholesterol; hsCRP, high-sensitivity C-reactive protein; ln, natural logarithm; SD, standard deviation.

Table 2 CKD Transition Probabilities According to Non-Traditional and Conventional Cardiovascular Risk Factors

	Transition 1: From No CKD into ≥ Low Risk		Transition 2: From ≤ Low Risk into ≥ Moderate Risk		Transition 3: From ≤ Moderate Risk into ≥ High Risk
	Black Participants	White Participants	Black Participants	White Participants	Black Participants	White Participants
Overall n/N at risk (% Transition)	586/1778 (33.0)	495/1940 (25.5)	321/2021 (15.9)	173/2148 (8.1)	174/2145 (8.1)	45/2201 (2.0)
Non-traditional risk factors
FVC*
N transition/Total sample	584/1721	492/1904	318/1946	171/2104	173/2063	45/2156
Predictor Category
Bottom quartile, n/N at risk (% Transition)	177/396 (44.7)	174/473 (36.8)	99/477 (20.8)	54/528 (10.2)	43/513 (8.4)	17/539 (3.15)
Top quartile, n/N at risk (% Transition)	117/454 (25.8)	81/497 (16.3)	72/494 (14.6)	31/530 (5.9)	45/514 (8.8)	9/540 (1.7)
Plasma GlycA
N transition/Total sample	502/1415	450/1719	265/1605	162/1900	147/1707	41/1946
Predictor Category
Bottom quartile, n/N at risk (% Transition)	77/282 (27.3)	119/528 (22.5)	44/309 (14.2)	42/578 (7.3)	26/331 (7.9)	10/588 (1.7)
Top quartile, n/N at risk (% Transition)	171/404 (42.3)	108/319 (33.9)	95/485 (19.6)	46/363 (12.7)	45/521 (8.6)	15/378 (4.0)
ln(serum hsCRP)
N transition/Total sample	586/1751	495/1919	321/1983	173/2127	174/2106	45/2179
Predictor Category
Bottom quartile, n/N at risk (% Transition)	89/339 (26.3)	126/620 (20.3)	41/370 (11.1)	33/676 (4.9)	28/385 (7.3)	4/689 (0.6)
Top quartile, n/N at risk (% Transition)	221/573 (38.6)	98/297 (33.0)	117/661 (17.7)	39/337 (11.6)	58/707 (8.2)	13/355 (3.7)
Serum urate^†
N transition/Total sample	586/1778	495/1938	321/2021	173/2145	174/2145	45/2198
Predictor Category
Bottom quartile, n/N at risk (% Transition)	118/501 (23.6)	105/451 (23.3)	47/553 (8.5)	29/505 (5.7)	27/573 (4.7)	4/518 (0.8)
Top quartile, n/N at risk (% Transition)	194/430 (45.1)	141/421 (33.5)	120/513 (23.4)	61/475 (12.8)	80/570 (14.0)	21/500 (4.2)
Sum of 4 serum carotenoids*
N transition/Total sample	565/1635	490/1861	303/1847	172/2059	166/1963	45/2108
Predictor Category
Bottom quartile, n/N at risk (% Transition)	143/383 (37.3)	141/460 (30.7)	72/436 (16.5)	60/509 (11.8)	49/484 (10.1)	27/527 (5.1)
Top quartile, n/N at risk (% Transition)	134/430 (31.2)	116/468 (24.8)	64/474 (13.5)	30/519 (5.8)	36/494 (7.3)	2/527 (0.4)
Conventional cardiovascular risk factors
Pack-year of smoking
n/N at risk (% Transition)
0	319/941 (33.9)	244/1058 (23.1)	171/1062 (16.1)	80/1176 (6.8)	84/1118 (7.5)	20/1202 (1.7)
≥0 – < 10	139/485 (28.7)	137/498 (27.5)	76/556 (13.7)	48/543 (8.8)	50/597 (8.4)	10/557 (1.8)
≥10	128/352 (36.4)	114/384 (29.7)	74/403 (18.4)	45/429 (10.5)	40/430 (9.3)	15/442 (3.4)
Hypertension
n/N at risk (% Transition)
No	168/836 (20.1)	286/1379 (20.7)	76/925 (8.2)	74/1501 (4.9)	38/956 (4.0)	13/1524 (0.9)
Yes	418/942 (44.4)	209/561 (37.3)	245/1096 (22.4)	99/647 (15.3)	136/1189 (11.4)	32/677 (4.7)
Diabetes
n/N at risk (% Transition)
No	427/1463 (29.2)	415/1769 (23.5)	216/1635 (13.2)	125/1940 (6.4)	120/1712 (7.0)	26/1973 (1.3)
Yes	159/315 (50.5)	80/171 (46.8)	105/386 (27.2)	48/208 (23.1)	54/433 (12.5)	19/228 (8.3)
High serum triglycerides
n/N at risk (% Transition)
No	383/1305 (29.4)	262/1126 (23.3)	186/1475 (12.6)	85/1239 (6.9)	87/1536 (5.7)	15/1262 (1.2)
Yes	203/473 (42.9)	233/814 (28.6)	135/546 (24.7)	88/909 (9.7)	87/609 (14.3)	30/939 (3.2)
Low HDL-C
n/N at risk (% Transition)
No	189/681 (27.8)	167/733 (22.8)	112/759 (14.8)	52/798 (6.5)	56/792 (7.1)	9/818 (1.1)
Yes	397/1097 (36.2)	328/1207 (27.2)	209/1262 (16.6)	121/1350 (9.0)	118/1353 (8.7)	36/1383 (2.6)
Obesity
n/N at risk (% Transition)
No	174/699 (24.9)	270/1171 (23.1)	84/783 (10.7)	81/1288 (6.3)	56/826 (6.8)	17/1313 (1.3)
Yes	412/1079 (38.2)	225/769 (29.3)	237/1238 (19.1)	92/860 (10.7)	118/1319 (9.0)	28/888 (3.2)

Notes: Sample sizes at risk and unadjusted % transition in Black and White participants are presented. *Race-specific quartiles were used. ^†Sex-specific quartiles were used.

Abbreviations: CKD, chronic kidney disease; FVC, forced vital capacity; HDL-C, high-density lipoprotein cholesterol; hsCRP, high-sensitivity C-reactive protein; ln, natural logarithm; SD, standard deviation.

Table 3 Adjusted HRs of CKD Progression Associated with Black Participants (Vs White Participants), Adjusted for Time-Varying Predictors, One at a Time and Simultaneously

	CKD Risk Category Transitions
	Transition 1: From No CKD into ≥ Low Risk	Transition 2: From ≤ Low Risk into ≥ Moderate Risk	Transition 3: From ≤ Moderate Risk into ≥ High Risk
Black participants (vs White participants)*
n/N	1081/3718	494/4169	219/4346
HR (CI)	1.38 (1.22–1.57)	2.25 (1.85–2.73)	4.49 (3.19–6.32)
Black participants (vs White participants) after further adjustment for each variable below
FVC (L)
n/N	975/3718	443/4169	199/4346
HR (95% CI)	1.16 (0.99–1.35)	1.73 (1.36–2.20)	3.63 (2.42–5.44)
Change race β^†	−0.174	−0.263	−0.213
% Change race β^†	–54.8	–32.2	–14.2
Plasma GlycA
n/N	952/3134	427/3505	188/3653
HR (95% CI)	1.37 (1.20–1.57)	2.07 (1.68–2.54)	4.45 (3.10–6.40)
Change race β^†	−0.007	−0.08	−0.009
% Change race β^†	–2.20	–10.4	–0.60
ln(serum hsCRP)
n/N	1023/3718	465/4169	207/4346
HR (95% CI)	1.36 (1.19–1.55)	2.09 (1.71–2.57)	4.41 (3.09–6.28)
Change race β^†	−0.015	−0.07	−0.018
% Change race β^†	–6.30	–8.80	–1.20
Serum urate
n/N	1081/3718	494/4169	219/4346
HR (95% CI)	1.39 (1.22–1.58)	2.22 (1.82–2.70)	4.34 (3.08–6.11)
Change race β^†	0.007	−0.01	−0.034
% Change race β^†	1.10	–1.70	–2.30
Sum of 4 serum carotenoids
n/N	1000/3718	449/4169	199/4346
HR (95% CI)	1.35 (1.19–1.55)	2.08 (1.70–2.55)	4.33 (3.03–6.17)
Change race β^†	−0.022	−0.08	−0.036
% Change race β^†	–6.40	–9.70	–2.50
Pack-year of smoking ≥10
n/N	1081/3718	494/4169	219/4346
HR (95% CI)	1.41 (1.24–1.60)	2.29 (1.88–2.79)	4.56 (3.23–6.42)
Change race β^†	0.022	0.018	0.015
% Change race β^†	5.60	2.50	0.90
Hypertension
n/N	1081/3718	494/4169	219/4346
HR (95% CI)	1.25 (1.10–1.42)	1.91 (1.56–2.33)	3.65 (2.58–5.17)
Change race β^†	−0.099	−0.16	−0.207
% Change race β^†	–30.9	–20.1	–13.7
Diabetes
n/N	1081/3718	494/4169	219/4346
HR (95% CI)	1.33 (1.17–1.52)	2.10 (1.72–2.55)	4.17 (2.96–5.87)
Change race β^†	−0.037	−0.07	−0.074
% Change race β^†	–11.0	–8.70	–5.00
High serum triglycerides
n/N	1081/3718	494/4169	219/4346
HR (95% CI)	1.46 (1.29–1.66)	2.38 (1.95–2.90)	4.93 (3.50–6.95)
Change race β^†	0.056	0.056	0.093
% Change race β^†	17.2	7.10	6.20
Low HDL–C
n/N	1081/3718	494/4169	219/4346
HR (95% CI)	1.39 (1.22–1.58)	2.26 (1.86–2.75)	4.55 (3.24–6.40)
Change race β^†	0.007	0.004	0.013
% Change race β^†	1.50	0.80	0.90
Obesity
n/N	1081/3718	494/4169	219/4346
HR (95% CI)	1.29 (1.14–1.47)	2.03 (1.66–2.48)	4.18 (2.96–5.91)
Change race β^†	−0.067	−0.1	−0.072
% Change race β^†	–20.8	–12.5	–4.70
Black participants (vs White participants) after further adjustment for all variables
n/N	867/3718	387/4169	175/4346
Change race β^†	−0.174	−0.39	−0.111
HR (95% CI)	1.16 (0.98–1.38)	1.53 (1.17–1.99)	4.02 (2.60–6.22)
% Change race β^†	–53.6	–47.5	–7.40

Notes: *Adjusted for age, sex, and education. ^†The percent change was calculated from the originally estimated logarithms of HR for race relative to the estimated logarithms of HR for race adjusted for clinical predictors at a time.

Abbreviations: CKD, chronic kidney disease; FVC, forced vital capacity; HDL-C, high-density lipoprotein cholesterol; HR, hazard ratio; hsCRP, high-sensitivity C-reactive protein; ln, natural logarithm; SD, standard deviation.