Association of different glucose traits with kidney function decline risk in a Chinese community-based population without chronic kidney disease

Figures & data

Table 1 Baseline characteristics of all eligible participants

Variable	Total	Non-DM	DM	P-value
N	3,738	2,844	894
Age, years	56.65±8.51	55.66±8.13	59.78±8.92	<0.001
Male, n (%)	1,339 (35.80%)	941 (33.10%)	398 (44.50%)	<0.001
BMI, kg/m^2	26.04±3.36	25.85±3.36	26.67±3.27	<0.001
SBP, mmHg	133.25±16.45	131.67±16.12	138.29±16.48	<0.001
DBP, mmHg	75.01±9.72	74.99±9.50	75.08±10.40	0.951
Total cholesterol, mmol/L	5.32±1.00	5.32±0.97	5.30±1.11	0.553
Triglycerides, mmol/L	1.30 (0.92–1.87)	1.26 (0.90–1.79)	1.47 (1.01–2.14)	<0.001a
FPG, mmol/L	6.15±1.76	5.51±0.51	8.18±2.59	<0.001
2 h-PG, mmol/L	8.55±4.04	6.83±1.67	14.03±4.47	<0.001
Baseline eGFR, mL/min/1.73 m^2	101.12±10.64	101.71±10.32	99.22±11.42	<0.001
Current smoking, n (%)	701 (18.80%)	518 (18.20%)	183 (20.50%)	0.132
Current drinking, n (%)	67 (1.80%)	43 (1.50%)	24 (2.70%)	0.021
Hypertension, n (%)	1,816 (48.60%)	1,217 (42.80%)	599 (67.00%)	<0.001
Cardiovascular disease, n (%)	471 (12.60%)	279 (9.80%)	192 (21.50%)	<0.001
Hypoglycemic drugs, n (%)	381 (10.20%)	0 (0.00%)	381 (43.10%)	<0.001
Antihypertensive drugs, n (%)	1,175 (31.60%)	747 (26.40%)	428 (48.10%)	<0.001
Lipid-lowering drugs, n (%)	394 (10.60%)	236 (8.40%)	158 (17.80%)	<0.001

Notes: Normally distributed continuous variables were presented as mean ± SD and compared using independent t-test. Abnormally distributed continuous variables were expressed as median and IQR, and

a compared using Kruskal–Wallis Test.

Abbreviations: BMI, body mass index; DM, diabetes mellitus; DBP, diastolic blood pressure; eGFR, estimated glomerular filtration rate; FPG, fasting plasma glucose; 2 h-PG, 2-hour plasma glucose; SBP, systolic blood pressure; IQR, interquartile range.

Table 2 Associations of different blood glucose traits and KFD according to DM status

KFD	Crude model	P-value	Model-1	P-value	Model-2	P-value
	OR (95% CI)		OR (95% CI)		OR (95% CI)
Total
FPG, mmol/L	1.21 (1.16, 1.27)	<0.001	1.23 (1.16, 1.31)	<0.001	1.26 (1.14, 1.39)	<0.001
2 h-PG, mmol/L	1.08 (1.06, 1.11)	<0.001	1.07 (1.04, 1.11)	<0.001	0.99 (0.94, 1.03)	0.562
Non-DM
FPG, mmol/L	1.41 (1.06, 1.89)	0.019	1.46 (1.07, 1.98)	0.017	1.43 (1.04, 1.99)	0.030
2 h-PG, mmol/L	1.06 (0.97, 1.16)	0.190	1.05 (0.95, 1.16)	0.305	1.01 (0.92, 1.12)	0.783
DM
FPG, mmol/L	1.17 (1.10, 1.25)	<0.001	1.19 (1.11, 1.28)	<0.001	1.27 (1.13, 1.42)	<0.001
2 h-PG, mmol/L	1.06 (1.02, 1.11)	0.003	1.06 (1.01, 1.10)	0.017	0.95 (0.89, 1.02)	0.136

Notes: Model-1: including either FPG or 2 h-PG, adjusted for age, sex, BMI, baseline eGFR, current smoking, current drinking, total cholesterol, triglyceride, hypertension, CVD history, antihypertensive drugs, hypoglycemic drugs, and lipid-lowering drugs. Model-2: including both the FPG and 2 h-PG, adjusted by variables in Model-1 plus 2 h-PG for FPG and FPG for 2 h-PG, respectively.

Abbreviations: BMI, body mass index; CVD, cardiovascular disease; DM, diabetes mellitus; eGFR, estimated glomerular filtration rate; FPG, fasting plasma glucose; 2 h-PG, 2-hour plasma glucose; KFD, kidney function decline.

Table 3 Associations of different FPG levels and KFD

KFD	Incidence, n (%)	Crude analysis		Multiple analysisa
		OR (95% CI)	P-value	OR (95% CI)	P-value
FPG, mmol/L
<5.6	96 (5.5)	1.0 (Ref)		1.0 (Ref)
≥5.6, <6.1	48 (6.0)	1.09 (0.76, 1.56)	0.627	1.02 (0.71, 1.48)	0.897
≥6.1, <7.0	61 (10.6)	2.07 (1.48, 2.89)	<0.001	1.83 (1.27, 2.65)	0.001
≥7.0	84 (14.2)	2.88 (2.11, 3.92)	<0.001	2.51 (1.53, 4.12)	<0.001
P for trend			<0.001		<0.001

Notes:

a Adjusted for age, sex, BMI, baseline eGFR, current smoking, current drinking, total cholesterol, triglyceride, hypertension, CVD history, antihypertensive drugs, hypoglycemic drugs, lipid-lowering drugs and 2 h-PG.

Abbreviations: 2 h-PG, 2-hour plasma glucose; BMI, body mass index; CVD, cardiovascular disease; eGFR, estimated glomerular filtration rate; FPG, fasting plasma glucose; KFD, kidney function decline.

Figure 1 Subgroup analyses for the association between KFD and FPG level.

Note: Variables in the model: age, sex, BMI, baseline eGFR (grouped by median value), 2 h-PG, current smoking, current drinking, total cholesterol, triglyceride, hypertension, cardiovascular disease, antihypertensive drugs, hypoglycemic drugs, and lipid-lowering drugs.
Abbreviations: 2 h-PG, 2-hour plasma glucose; BMI, body mass index; eGFR, estimated glomerular filtration rate; KFD, kidney function decline; FPG, fasting plasma glucose.

Figure S1 CONSORT flow diagram.

Abbreviations: 2 h-PG, 2-hour plasma glucose; eGFR, estimated glomerular filtration rate; FBG, fasting blood glucose.

Table S1 STROBE Statement-checklist of items that should be included in reports of observational studies

	Item no	Recommendation	Page no	Relevant text from manuscript
Title and abstract	1	a) Indicate the study’s design with a commonly used term in the title or the abstract	1	1–2
		b) Provide in the abstract an informative and balanced summary of what was done and what was found	2	35–48
Introduction
Background/rationale	2	Explain the scientific background and rationale for the investigation being reported	3	55–70
Objectives	3	State specific objectives, including any pre-specified hypotheses	3	71–73
Methods
Study design	4	Present key elements of study design early in the paper	3	76
Setting	5	Describe the setting, locations, and relevant dates, including periods of recruitment, exposure, follow-up, and data collection	3–4	76–80
Participants	6	a) Cohort study – Give the eligibility criteria and the sources and methods of selection of participants. Describe methods of follow-up	3–4	76–85
		Case–control study – Give the eligibility criteria, the sources and methods of case ascertainment, and control selection. Give the rationale for the choice of cases and controls
		Cross-sectional study – Give the eligibility criteria and the sources and methods of selection of participants
		b) Cohort study – For matched studies, give matching criteria and number of exposed and unexposed
		Case–control study – For matched studies, give matching criteria and the number of controls per case
Variables	7	Clearly define all outcomes, exposures, predictors, potential confounders, and effect modifiers. Give diagnostic criteria, if applicable	3–5	76–119
Data sources/measurement	8a	For each variable of interest, give sources of data and details of methods of assessment (measurement). Describe comparability of assessment methods if there is more than one group	3–4	76–104
Bias	9	Describe any efforts to address potential sources of bias	5	121–139
Study size	10	Explain how the study size was arrived at
Quantitative variables	11	Explain how quantitative variables were handled in the analyses. If applicable, describe which groupings were chosen and why	5	121–139
Statistical methods	12	a) Describe all statistical methods, including those used to control for confounding	5	121–144
		b) Describe any methods used to examine subgroups and interactions	5	135–139
		c) Explain how missing data were addressed	3	80–81
		d) Cohort study – If applicable, explain how loss to follow-up was addressed	3	77–80
		Case–control study – If applicable, explain how matching of cases and controls was addressed
		Cross-sectional study – If applicable, describe analytical methods taking account of sampling strategy
		e) Describe any sensitivity analyses	6	164–165
Results
Participants	13a	a) Report numbers of individuals at each stage of study – eg, numbers potentially eligible, examined for eligibility, confirmed eligible, included in the study, completing follow-up, and analyzed	3–4	77–84
		b) Give reasons for non-participation at each stage	3–4	76–84
		c) Consider use of a flow diagram
Descriptive data	14a	a) Give characteristics of study participants (eg, demographic, clinical, social), information on exposures, and potential confounders	6	149–153
		b) Indicate number of participants with missing data for each variable of interest	3–4	78–84
		c) Cohort study – Summarize follow-up time (eg, average and total amount)	6	149–150
Outcome data	15a	Cohort study – Report numbers of outcome events or summary measures over time	6	150–152
		Case–control study – Report numbers in each exposure category, or summary measures of exposure
		Cross-sectional study – Report numbers of outcome events or summary measures
Main results	16	a) Give unadjusted estimates and, if applicable, confounder-adjusted estimates and their precision (eg, 95% CI). Make clear which confounders were adjusted for and why they were included	6	154–168
		b) Report category boundaries when continuous variables were categorized	6	150–151
		c) If relevant, consider translating estimates of relative risk into absolute risk for a meaningful time period
Other analyses	17	Report other analyses done – eg, analyses of subgroups and interactions and sensitivity analyses	6–7	166–180
Discussion
Key results	18	Summarize key results with reference to study objectives	7	182–185
Limitations	19	Discuss limitations of the study, taking into account sources of potential bias or imprecision.	9	245–260
Interpretation	20	Give a cautious overall interpretation of results considering objectives, limitations, multiplicity of analyses, results from similar studies, and other relevant evidence	7–9	186–260
Generalizability	21	Discuss the generalizability (external validity) of the study results	9	242–244
Other information
Funding	22	Give the source of funding and the role of the funders for the present study and, if applicable, for the original study on which the present article is based	10	270–272

Notes:

a Gives information separately for cases and controls in case–control studies and, if applicable, for exposed and unexposed groups in cohort and cross-sectional studies. An explanation and elaboration article discusses each checklist item and gives a methodological background and published examples of transparent reporting. The STROBE checklist is best used in conjunction with this article (freely available on the Websites of PLoS Medicine at http://www.plosmedicine.org/, Annals of Internal Medicine at http://www.annals.org/, and Epidemiology at http://www.epidem.com/). Information on the STROBE Initiative is available at www.strobe-statement.org.