Associations of low-carbohydrate with mortality in chronic kidney disease

Figures & data

Table 1. Characteristics of participants with CKD by carbohydrate intake quantiles.

Characteristic	Overall, N = 3,683	Quantile groups of energy intake from carbohydrates (% of total energy intake)
		Quantile1**, N = 921	Quantile2**, N = 920	Quantile3**, N = 921	Quantile4**, N = 921	p-Value
Age (mean ± SD)	65.5 (16.3)	64.4 (15.3)	65.2 (16.4)	66.5 (16.5)	65.8 (16.8)	<0.001
Female (n, %)	1,922 (52.2%)	412 (44.7%)	480 (52.2%)	507 (55.0%)	523 (56.8%)	<0.001
Race/ethnicity (n, %)						0.008
Non-Hispanic Black	702 (19.1%)	191 (20.7%)	177 (19.2%)	156 (16.9%)	178 (19.3%)
Non-Hispanic White	2,093 (56.8%)	508 (55.2%)	545 (59.2%)	553 (60.0%)	487 (52.9%)
Other	888 (24.1%)	222 (24.1%)	198 (21.5%)	212 (23.0%)	256 (27.8%)
ACEI/ARB usage (n, %)	1,547 (42.0%)	446 (48.4%)	378 (41.1%)	359 (39.0%)	364 (39.5%)	<0.001
Poverty income ratio (n, %)						<0.001
0–1.29	1,070 (29.1%)	210 (22.8%)	277 (30.1%)	278 (30.2%)	305 (33.1%)
1.3–3.49	1,764 (47.9%)	457 (49.6%)	442 (48.0%)	437 (47.4%)	428 (46.5%)
3.5+	849 (23.1%)	254 (27.6%)	201 (21.8%)	206 (22.4%)	188 (20.4%)
Alcohol consumption (g) (n, %)						<0.001
0	3,010 (81.7%)	708 (76.9%)	760 (82.6%)	761 (82.6%)	781 (84.8%)
0–14	215 (5.8%)	62 (6.7%)	49 (5.3%)	63 (6.8%)	41 (4.5%)
14–28	177 (4.8%)	59 (6.4%)	40 (4.3%)	37 (4.0%)	41 (4.5%)
28–42	100 (2.7%)	25 (2.7%)	33 (3.6%)	22 (2.4%)	20 (2.2%)
>42	181 (4.9%)	67 (7.3%)	38 (4.1%)	38 (4.1%)	38 (4.1%)
Smoker (n, %)	1,834 (49.9%)	521 (56.6%)	477 (51.9%)	417 (45.3%)	419 (45.6%)	<0.001
Physical measurement (mean ± SD; n, %)
Systolic blood pressure (mmHg)	135.4 (23.7)	134.6 (23.6)	135.8 (24.0)	134.7 (23.6)	136.4 (23.5)	0.165
Body mass index (kg/m^2)						0.004
<21	231 (6.3%)	47 (5.1%)	63 (6.8%)	52 (5.6%)	69 (7.5%)
21–24.9	828 (22.5%)	186 (20.2%)	193 (21.0%)	222 (24.1%)	227 (24.6%)
25–29.9	1,181 (32.1%)	279 (30.3%)	292 (31.7%)	314 (34.1%)	296 (32.1%)
30–34.9	815 (22.1%)	216 (23.5%)	214 (23.3%)	197 (21.4%)	188 (20.4%)
> =35	628 (17.1%)	193 (21.0%)	158 (17.2%)	136 (14.8%)	141 (15.3%)
Leisure time physical activity (MET-h/week)						0.565
0	2,269 (61.7%)	553 (60.1%)	584 (63.5%)	554 (60.2%)	578 (63.0%)
0–10.5	621 (16.9%)	153 (16.6%)	156 (17.0%)	156 (17.0%)	156 (17.0%)
10.5–21	327 (8.9%)	84 (9.1%)	81 (8.8%)	86 (9.3%)	76 (8.3%)
> =21	460 (12.5%)	130 (14.1%)	98 (10.7%)	124 (13.5%)	108 (11.8%)
Laboratory test (n, %; mean ± SD)
Estimate glomerular filtration rate (ml/min/1.73m^2)						<0.001
<15	48 (1.4%)	17 (1.9%)	15 (1.7%)	9 (1.0%)	7 (0.8%)
15–30	147 (4.1%)	29 (3.3%)	38 (4.3%)	33 (3.7%)	47 (5.3%)
30-45	469 (13.2%)	116 (13.2%)	97 (10.9%)	136 (15.3%)	120 (13.5%)
45-60	1,265 (35.7%)	295 (33.5%)	316 (35.5%)	356 (40.1%)	298 (33.6%)
> =60	1,615 (45.6%)	423 (48.1%)	423 (47.6%)	353 (39.8%)	416 (46.8%)
Urinary albumin creatinine ratio (mg/g)						0.056
<30	1,244 (34.5%)	291 (32.1%)	300 (33.6%)	341 (37.8%)	312 (34.6%)
30-300	1,977 (54.9%)	504 (55.6%)	488 (54.7%)	483 (53.5%)	502 (55.7%)
> =300	382 (10.6%)	112 (12.3%)	104 (11.7%)	79 (8.7%)	87 (9.7%)
H1bAc (%)	6.2 (1.4)	6.3 (1.6)	6.3 (1.5)	6.1 (1.4)	6.0 (1.3)	<0.001
Comorbidities (n, %)
Diabetes	1,220 (33.1%)	385 (41.8%)	313 (34.0%)	267 (29.0%)	255 (27.7%)	<0.001
Hypertension	2,657 (72.1%)	683 (74.2%)	660 (71.7%)	650 (70.6%)	664 (72.1%)	0.382
Hypercholesterolemia	2,542 (69.3%)	657 (71.6%)	646 (70.6%)	618 (67.6%)	621 (67.4%)	0.128
Congestive heart failure	371 (10.2%)	91 (10.0%)	97 (10.6%)	101 (11.0%)	82 (9.0%)	0.508
Myocardial infarction	422 (11.5%)	114 (12.4%)	101 (11.0%)	108 (11.8%)	99 (10.8%)	0.708
Stroke	350 (9.5%)	84 (9.2%)	84 (9.2%)	84 (9.1%)	98 (10.7%)	0.597
Cancer	639 (17.4%)	153 (16.6%)	146 (15.9%)	198 (21.5%)	142 (15.5%)	0.002
Dietary intake (mean ± SD)
Total energy intake (kcal/d)*	1,794.0 (668.0)	1,892.6 (699.0)	1,801.0 (653.1)	1,786.1 (653.0)	1,696.5 (652.1)	<0.001
Carbohydrate (%)	50.2 (8.7)	39.0 (3.8)	47.3 (1.7)	53.2 (1.8)	61.3 (3.5)	<0.001
Sugar (%)	21.7 (9.0)	14.6 (5.8)	19.6 (6.6)	23.9 (7.2)	28.8 (9.1)	<0.001
Fiber (g)	15.3 (8.3)	13.6 (7.5)	14.5 (7.5)	16.1 (8.5)	17.1 (9.3)	<0.001
Protein (%)	16.2 (4.8)	19.0 (5.2)	16.7 (4.5)	15.3 (4.1)	13.7 (3.7)	<0.001
Animal protein (%)	10.1 (5.3)	13.3 (5.9)	10.7 (5.0)	9.1 (4.3)	7.4 (3.9)	<0.001
Plant protein (%)	4.9 (2.1)	4.4 (2.2)	4.7 (1.9)	5.0 (2.0)	5.4 (2.3)	<0.001
Fat (%)	33.6 (7.9)	42.0 (5.6)	35.9 (4.6)	31.5 (4.3)	25.0 (4.6)	<0.001
Saturated fat (%)	10.9 (3.6)	13.6 (3.5)	11.7 (3.0)	10.3 (2.8)	8.1 (2.5)	<0.001
Monounsaturated fat (%)	12.2 (3.5)	15.5 (3.0)	13.0 (2.5)	11.2 (2.2)	8.9 (2.2)	<0.001
Polyunsaturated fat (%)	7.6 (3.1)	9.3 (3.5)	8.0 (2.8)	7.2 (2.7)	5.8 (2.2)	<0.001
Animal fat (%)	14.4 (8.1)	20.1 (9.0)	15.7 (7.0)	12.6 (6.3)	9.2 (5.2)	<0.001
Plant fat (%)	14.7 (7.7)	16.5 (9.1)	15.3 (7.6)	14.3 (7.0)	12.5 (6.2)	<0.001

*Total energy intake from carbohydrate, protein and fat per day.

**Percentage of carbohydrate intake range for quantile1 (30.1-44.2%), quantile2 (44.2-50.2%), quantile3 (50.2-56.5%), quantile4 (56.5-70.0%).

MET: metabolic equivalent task.

Figure 1. Association between percentage energy intake of macronutrients and all-cause mortality in participants with CKD.

Table 2. Association between low carbohydrate/sugar diet and all-cause mortality by quantiles in participants with CKD.

	Quantile1	Quantile2	Quantile3	Quantile4	p-trend*	Per 25% increase**
Carbohydrate	1	1.14 (0.89-1.45)	1.23 (0.98-1.54)	1.35 (1.05-1.72)	0.014	1.24 (1.04-1.48)
Sugar	1	0.91 (0.70-1.17)	1.00 (0.81-1.24)	1.27 (1.00-1.61)	0.030	1.20 (1.02-1.42)

*p-value for HR trend as a percentage of energy intake from carbohydrate/sugar increased.

**Overall HR as a percentage of energy intake from carbohydrate/sugar increased 25%.

Figure 2. Association between percentage energy intake of macronutrients and all-cause mortality in participants with CKD subgroups (eGFR <60 mL/min·1.73m²; ACR ≥30 mg/g).

Figure 3. Iso-caloric replacement analysis on replacing carbohydrates with other macronutrients in participants with CKD.

Figure 4. Iso-caloric replacement analysis on replacing sugar with other macronutrients in participants with CKD.

Availability of data and materials

The datasets analyzed during the current study are available at [https://wwwn.cdc.gov/nchs/nhanes/Default.aspx].