Associations Between Mean HbA1c, HbA1c Variability, and Both Mortality and Macrovascular Complications in Patients with Diabetes Mellitus: A Registry-Based Cohort Study

Figures & data

Table 1 Baseline Characteristics of Overall Study Population

	Population (n = 75,334)
Female (%)	38,339 (50.9)
Age (on Jan 1, 2015)
Mean (SD)	66.5 (12.0)
Median	67
IQR	59–75
Min, Max	19, 105
Ethnicity (n (%))
Chinese	54,203 (72)
Malay	10,674 (14.2)
Indian	7889 (10.5)
Other	2568 (3.4)
Housing type (n (%))
1- and 2-room PH	5696 (7.6)
3-room PH	19,167 (25.4)
4-room PH	22,109 (29.3)
5-room PH and executive flats	16,922 (22.5)
Private condominiums	4257 (5.7)
Private landed housing	3770 (5.0)
Unknown	3413 (4.5)
Diabetes type (n (%))
Type 1 Diabetes Mellitus	463 (0.6)
Type 2 Diabetes Mellitus	74,803 (99.3)
Other^†	65 (0.1)
Duration of diabetes (years)
Mean (SD)	10.7 (6.8)
Median	10
IQR	6–14
Min, Max	1, 60
Unknown (n (%))	145 (0.2)
BMI (kg/m2)
Mean (SD)	26.5 (4.95)
Median	25.8
IQR	23.2–29
Unknown (n (%))	14,262 (18.9)
Smoking status (n (%))
Unknown	48,174 (63.9)
Never-smoked	23,430 (31.1)
Ex-smoker	2689 (3.6)
Current smoker	1041 (1.4)
Hypertension (n (%))
Present	66,755 (88.6)
Not present	7456 (9.9)
Unknown	1123 (1.5)
Average systolic blood pressure 2013–2014 (mmHg)
<100	324 (0.4)
100–109	2138 (2.8)
110–119	9096 (12.1)
120–129	21,392 (28.4)
130–139	22,704 (30.1)
140–149	10,704 (14.2)
150–159	3959 (5.3)
160–169	1295 (1.7)
≥170	690 (0.9)
Unknown	3032 (4.0)
Average diastolic blood pressure 2013–2014 (mmHg)
<60	6364 (8.4)
30,895 (41)60–69	28,153 (37.4)
70–79	6171 (8.2)
80–89	643 (0.9)
90–99	77 (0.1)
≥100	3031 (4.0)
Unknown	6364 (8.4)
LDL cholesterol (mmol/L)
Mean (SD)	2.35 (0.76)
Median	2.24
IQR	1.86–2.7
Unknown (n (%))	8607 (11.4)
CKD stage
Stage 1	13,408 (17.8)
Stage 2	4158 (5.5)
Stage 3A	8880 (11.8)
Stage 3B	4976 (6.6)
Stage 4	2465 (3.3)
Stage 5	1412 (1.9)
Unknown	40,035 (53.1)
Urine Albumin Creatinine Ratio category
A1 (<30 mg/g)	3144 (4.2)
A2 (30–300 mg/g)	1873 (2.5)
A3 (>300 mg/g)	1150 (1.5)
Unknown	69,167 (91.8)
Medications
Not on medications	13,347 (17.7)
On any oral agent	59,079 (78.4)
Only on oral agents	46,062 (61.1)
On both oral agents and insulin	13,017 (17.3)
Only on insulin	2908 (3.9)
On medications (by type)
Metformin	52,649 (69.9)
Sulphonylurea	36,407 (48.3)
Meglitinide	52 (0.1)
Acarbose	6267 (8.3)
Thiazolidinediones	139 (0.2)
DPP4 inhibitors	4379 (5.8)
SGLT-2 inhibitors	8 (0.0)
GLP-1 receptor agonists	88 (0.1)
Insulin	15,925 (21.1)

Note: ^†Other DM types include drug-induced, gestational, monogenic, and secondary diabetes.

Figure 1 Adjusted HRs by HbA1c level for (A) all-cause mortality, (B) IHD, (C) AMI, (D) PAD, (E) haemorrhagic stroke and (F) ischemic stroke.

Figure 2 Adjusted HRs by HbA1c level, with HVS included in the model, for (A) all-cause mortality, (B) IHD, (C) AMI, (D) PAD, (E) haemorrhagic stroke and (F) ischemic stroke.

Figure 3 Adjusted HRs by HbA1c Variability Score, for (A) all-cause mortality, (B) IHD, (C) AMI, (D) PAD, (E) haemorrhagic stroke and (F) ischemic stroke.