Predictive Ability of Visit-to-Visit Variability of HbA1c Measurements for the Development of Diabetic Kidney Disease: A Retrospective Longitudinal Observational Study

Table 3

Association of the risk of microalbuminuria and eGFR stage progression with continuous variables of visit-to-visit variability of HbA1c, measured as 4 indices using a Cox proportional hazards model.

Index	Incidence of microalbuminuria		eGFR stage progression from G1		eGFR stage progression from G2		eGFR stage progression from G3
	HR (95% CI)^a	value	HR (95% CI)^a	value	HR (95% CI)^a	value	HR (95% CI)^a	value
HbA1c-SD	1.18 (1.01-1.37)	0.033	1.23 (1.06-1.43)	0.008	1.09 (0.86-1.37)	0.483	1.09 (0.73-1.61)	0.675
HbA1c-CV	1.17 (1.03-1.34)	0.019	1.21 (1.05-1.39)	0.008	1.09 (0.89-1.33)	0.400	1.09 (0.77-1.53)	0.634
HbA1c-AUC	1.20 (1.03-1.40)	0.019	1.22 (1.05-1.42)	0.010	1.09 (0.84-1.43)	0.509	1.04 (0.67-1.62)	0.848
HbA1c-HVS	1.00 (0.85-1.17)	0.952	1.03 (0.88-1.21)	0.735	1.18 (0.96-1.46)	0.105	0.99 (0.57-1.69)	0.958

^aAdjusted by age, sex, mean HbA1c over the 3-year period, duration of diabetes, SBP, LDL-C, eGFR (in the analysis of eGFR stage progression), and presence of ischemic heart disease and heart failure at baseline. eGFR: estimated glomerular filtration rate; HR: hazard ratio; CI: confidence interval; HbA1c-SD: internal standard deviation of HbA1c; HbA1c-CV: coefficient of variation of HbA1c; HbA1c-AUC: area under the HbA1c curve; HbA1c-HVS: HbA1c change score; SBP: systolic blood pressure; LDL-C: low-density lipoprotein cholesterol.