Metabolic dysfunction, rather than obesity, is a risk factor for chronic kidney disease in Chinese population

Figures & data

Figure 1. Flow chart of data cleansing. MetS: metabolic syndrome; BMI: body mass index; CKD: chronic kidney disease; CHARLS: China Health and Retirement Longitudinal Study.

Table 1. Baseline characteristics of included participants in CHARLS 2015.

Characteristics	Metabolic healthy (N = 7715)			Metabolic unhealthy (N = 4339)				p Values
	MHN N = 5186	MHOW N = 2047	MHO N = 482	MUN N = 884	MUOW N = 2208	MUO N = 1247
Age (years)
< 50	1092 (21.1%)	569 (27.8%)	158 (32.8%)	85 (9.6%)	410 (18.6%)	286 (22.9%)		<0.001
50–60	1603 (30.9%)	695 (34.0%)	181 (37.6%)	251 (28.4%)	754 (34.1%)	446 (35.8%)		–
60–70	1630 (31.4%)	589 (28.8%)	116 (24.1%)	332 (37.6%)	740 (33.5%)	370 (29.7%)		–
> 70	861 (16.6%)	194 (9.5%)	27 (5.6%)	216 (24.4%)	304 (13.8%)	145 (11.6%)		–
Gender
Male	2974 (57.3%)	1004 (49.0%)	192 (39.8%)	131 (14.8%)	811 (36.7%)	429 (34.4%)		<0.001
Female	2212 (42.7%)	1043 (51.0%)	290 (60.2%)	753 (85.2%)	1397 (63.3%)	818 (65.6%)
Marital status
Married with spouse	4296 (82.8%)	1757 (85.8%)	425 (88.2%)	670 (75.8%)	1835 (83.1%)	1063 (85.2%)		<0.001
Divorced/separated/widowed	890 (17.2%)	290 (14.2%)	57 (11.8%)	214 (24.2%)	373 (16.9%)	184 (14.8%)		–
Alcohol consumption
Drink more than once a month	1610 (31.1%)	571 (27.9%)	124 (25.8%)	143 (16.2%)	481 (21.8%)	239 (19.2%)		<0.001
Drink but less than once a month	506 (9.8%)	196 (9.6%)	44 (9.1%)	61 (6.9%)	195 (8.8%)	93 (7.5%)		–
None of these	3062 (59.1%)	1278 (62.5%)	313 (65.1%)	680 (76.9%)	1530 (69.4%)	914 (73.4%)		–
Cigarette consumption
Current smoker	1908 (36.9%)	498 (24.4%)	91 (18.9%)	107 (12.1%)	437 (19.8%)	201 (16.1%)		<0.001
Non-smoker	2616 (50.5%)	1265 (61.9%)	321 (66.6%)	710 (80.3%)	1481 (67.1%)	879 (70.5%)		–
Ex-smoker	652 (12.6%)	281 (13.7%)	70 (14.5%)	67 (7.6%)	290 (13.1%)	166 (13.3%)		–
Depression
None-depression	3162 (61.0%)	1331 (65.0%)	332 (68.9%)	469 (53.1%)	1385 (62.7%)	773 (62.0%)		<0.001
Depression	2024 (39.0%)	716 (35.0%)	150 (31.1%)	415 (46.9%)	823 (37.3%)	474 (38.0%)
Sleep duration
0–6 h	2531 (50.3%)	1010 (50.1%)	226 (47.9%)	451 (53.6%)	1050 (49.0%)	586 (48.0%)		0.002
6–8 h	1998 (39.7%)	850 (42.2%)	197 (41.7%)	294 (35.0%)	894 (41.7%)	519 (42.5%)		–
>8 h	505 (10.0%)	154 (7.6%)	49 (10.4%)	96 (11.4%)	199 (9.3%)	116 (9.5%)		–
Glucose (mg/dL)	97.1 (27.5)	95.8 (23.2)	94.1 (19.4)	115.8 (48.8)	115.8 (43.2)	116.5 (42.1)		<0.001
HDL (mg/dL)	54.3 (12.2)	51.6 (9.7)	52.1 (9.2)	48.0 (10.1)	45.9 (8.9)	45.3 (8.5)		<0.001
Triglycerides (mg/dL)	112.9 (68.2)	120.1 (64.8)	116.7 (53.4)	182.6 (97.8)	201.0 (107.6)	208.9 (105.4)		<0.001
LDL (mg/dL)	99.7 (28.2)	105.8 (28.2)	107.5 (27.9)	104.0 (30.0)	103.2 (28.6)	104.2 (31.1)		<0.001
Total cholesterol (mg/dL)	179.1 (35.3)	183.5 (34.6)	184.1 (33.6)	190.2 (38.0)	190.1 (36.4)	190.6 (38.8)		<0.001
Systolic pressure (mmHg)	124.2 (19.2)	125.8 (19.8)	126.9 (17.8)	133.3 (20.0)	135.0 (20.4)	136.0 (19.0)		<0.001
Diastolic pressure (mmHg)	73.4 (11.1)	75.6 (11.2)	77.1 (10.7)	75.7 (11.2)	79.3 (11.1)	81.3 (12.2)		<0.001
Hypertension
No	3193 (61.6%)	1248 (61.0%)	281 (58.3%)	272 (30.8%)	606 (27.4%)	246 (19.7%)		<0.001
Yes	1993 (38.4%)	799 (39.0%)	201 (41.7%)	612 (69.2%)	1602 (72.6%)	1001 (80.3%)		–
Abdominal obesity
No	4293 (82.8%)	723 (35.4%)	51 (10.6%)	0 (0.0%)	0 (0.0%)	0 (0.0%)		<0.001
Yes	889 (17.2%)	1320 (64.6%)	428 (89.4%)	884 (100.0%)	2,208 (100.0%)	1247 (100.0%)		–
BMI
18.0–24.0 kg/m^2	5186 (100.0%)	0 (0.0%)	0 (0.0%)	884 (100.0%)	0 (0.0%)	0 (0.0%)		<0.001
24.0–27.0 kg/m^2	0 (0.0%)	2047 (100.0%)	0 (0.0%)	0 (0.0%)	2208 (100.0%)	0 (0.0%)		–
> 27.0 kg/m^2	0 (0.0%)	0 (0.0%)	482 (100.0%)	0 (0.0%)	0 (0.0%)	1247 (100.0%)		–
CKD	230 (4.4%)	90 (4.4%)	13 (2.7%)	73 (8.3%)	131 (5.9%)	75 (6.0%)		–

MHN: metabolically healthy normal weight; MHOW: metabolically healthy overweight; MHO: metabolically healthy obesity; MUN: metabolically unhealthy normal weight; MUOW: metabolically unhealthy overweight; MUO: metabolically unhealthy obesity. N: number; HDL: high-density lipoprotein; LDL: low-density lipoprotein; BMI: body mass index; CKD: chronic kidney disease.

Table 2. Prevalence of chronic kidney disease classified by MetS-BMI phenotypes.

	Metabolic healthy (N = 7715)			Metabolic unhealthy (N = 4339)
Characters	MHN	MHOW	MHO	MUN	MUOW	MUO
Number of participants	5186	2047	482	884	2208	1247
CKD cases	230	90	13	73	131	75
Incidence rate (95% CI)	4.43 (3.90 − 5.03)	4.40 (3.59 − 5.37)	2.70 (1.57 − 4.59)	8.26 (6.61 − 10.27)	5.93 (5.02 − 7.00)	6.01 (4.82 − 7.48)

MHN: metabolically healthy normal weight; MHOW: metabolically healthy overweight; MHO: metabolically healthy obesity; MUN: metabolically unhealthy normal weight; MUOW: metabolically unhealthy overweight; MUO: metabolically unhealthy obesity. N: number; BMI: body mass index; CKD: chronic kidney disease.

Table 3. Association between MetS-BMI phenotypes and risk of CKD.

Mets-BMI phenotypes	Model 1	Model 2	Model 3	Model 4
MHN	Reference	Reference	Reference	Reference
MHOW	0.99 (0.77–1.27), p = 0.943	1.30 (1.00–1.69), p = 0.051	1.29 (0.99–1.68), p = 0.059	1.27 (0.98–1.67), p = 0.069
MHO	0.59 (0.34–1.05), p = 0.075	1.06 (0.59–1.90), p = 0.838	1.07 (0.60–1.91), p = 0.826	1.06 (0.59–1.89), p = 0.850
MUN	1.93 (1.48–2.55), p < 0.001	1.60 (1.17–2.19), p = 0.003	1.61 (1.18–2.19), p = 0.002	1.62 (1.19–2.21), p = 0.002
MUOW	1.35 (1.09–1.69), p = 0.006	1.54 (1.21–1.96), p < 0.001	1.55 (1.21–1.97), p < 0.001	1.55 (1.21–1.97), p < 0.001
MUO	1.37 (1.05–1.80), p = 0.019	1.81 (1.36–2.42), p < 0.001	1.78 (1.33–2.38), p < 0.001	1.77 (1.33–2.37), p < 0.001

MHN: metabolically healthy normal weight; MHOW: metabolically healthy overweight; MHO: metabolically healthy obesity; MUN: metabolically unhealthy normal weight; MUOW: metabolically unhealthy overweight; MUO: metabolically unhealthy obesity. N: number; BMI: body mass index; CKD: chronic kidney disease.