Trends in glycaemic control and morbidity over 10 years in patients with type 1 diabetes mellitus at Inkosi Albert Luthuli Central Hospital

Figures & data

Table 1: Clinical and laboratory characteristics of the individual-patient-level follow-up (IPLF) study group (n = 58) evaluated at three time points (2006, 2012, 2015)

Factor	2006 n = 58	2012 n = 58	2015 n = 58
Ethnicity:
African (Black)	44.8 (26)	–	–
Indian	48.3 (28)	–	–
White	5.2 (3)	–	–
Mixed race	1.7 (1)	–	–
Gender (m:f) (n)	22:36	–	–
Age (years)	30 (21–36)	–	–
Age at diagnosis (years)	18 (13–22)	–	–
Diabetes duration (years)	12 (6–19)	17 (12–23)	20 (15–26)
Presentation:
Ketoacidosis	29.3 (17)	–	–
Symptomatic	44.8 (26)	–	–
High glucose	13.8 (8)	–	–
Unknown	10.3 (6)	–	–
BMI (kg/m^2)	24.6 (22–28)	27.5 (24–31)^c	26.6 (24–30)^c
Systolic BP (mmHg)	121 (110–131)	128 (110–131)^b	129 (119–138)^b
Diastolic BP (mmHg)	74 (69–81)	69 (61–79)^b,d	76 (68–81)
Anti-GAD positive*	64.9 (37)	–	–
HbA1c (%), mean (SD)^†	9.9 (2.6)	8.7 (1.5)^c,d	9.1 (1.7)^a
(mmol/mol)^†	85 (28)	72 (16)^c,d	76 (19)^a
Serum lipids(mmol/l):
Total cholesterol	4.7 (4.2–5.4)	4.2 (4.0–5.0)^a	4.5 (4.0–5.0)
LDL cholesterol	2.4 (1.9–3.0)	2.1 (1.9–2.5)^c	2.2 (1.9–2.7)^b
HDL cholesterol	1.6 (1.3–2.0)	1.5 (1.3–1.8)^c	1.5 (1.2–1.9)^b
Triglycerides	1.2 (0.7–1.9)	1.1 (0.8–1.7)	1.0 (0.7–1.5)
iGFR (ml/min/m^2)	113 (98–128)	111 (92–126)	97 (82–124)^b
eGFR(ml/min/1.73m^2)	124(105–136)	116(101–134)^b	117(93–131)^b
Serum creatinine(µmol/l)	66(57–79)	65(56–75)	61(53–78)
Urine albumin/creatinine ratio:	1.2(0.6–2.6)	2.0(0.9–6.1)	1.0(0.4–4)
3–30 mg/mmol	19 (11)	34.5 (20)	22.4 (13)
>30 mg/mmol	15.5 (9)	13.8 (8)	5.2 (3)
≥3 mg/mmol	34.5(20)	48.3 (28)	27.6 (16)

Data shown as % (n), median (IQR) or mean (SD).

*N = 56 (2 missing values). ^†N = 57 (1 missing value).

BMI: body mass index; BP: blood pressure; GAD: glutamic acid decarboxylase; iGFR: isotope glomerular filtration rate; eGFR: estimated glomerular filtration rate; LDL: low density lipoprotein; HDL: high density lipoprotein.

P-values are for comparisons between the three groups by ANOVA, paired t-test or Wilcoxon signed-rank test for pairs of continuous variables and McNemar’s chi-square test for pairs of categorical variables.

^ap < 0.05, ^bp < 0.01, ^cp < 0.001 vs. 2006, ^dp < 0.05 vs. 2015.

Figure 1: Glycaemic and non-glycaemic parameters in the individual-patient-level follow-up (IPLF) study group (n = 58) according to study year. P-values are for comparisons between the three groups by McNemar’s chi-square test for pairs of categorical variables. ^ap < 0.01, ^bp < 0.001 vs. 2006.

Figure 2: Chronic complications in the individual-patient-level follow-up (IPLF) study (n = 58) according to study year. ACR: albumin creatinine ratio; iGFR: isotope glomerular filtration rate; eGFR: estimated glomerular filtration rate; MACE: major adverse cardiovascular event; p-values are for comparisons between the three groups by McNemar’s chi-square test for pairs of categorical variables. ^ap < 0.05, ^bp < 0.01 vs. 2006.

Table 2: Baseline (2006) characteristics and analysis of risk factors for retinopathy development in the individual-patient-level follow-up (IPLF) study group (n = 52)

Factor	Bivariate analysis
	2015		Regression analysis
	No retinopathy n = 41	Retinopathy n = 11		OR	95% CI	p
Ethnicity:
Black (n = 22)	82 (18)	18 (4)
Indian (n = 26)	81 (21)	19 (5)
Other (n = 4)	50 (2)	50 (2)
Sex (M:F) (n)	17:24	3:8
Age (years)	29.3 (20–36)	36.2 (29–41)
Diabetes duration (years)	10.9 (5–14)	17.7 (13.5–24)*		1.14	1.0–1.3	0.03
Anti-GAD positive (%)	91 (3)	9 (3)*		0.05	0.01–0.4	0.01
Hypertension (%)	71 (10)	29 (4)
BMI (kg/m^2)	24.9 (22.6–27.6)	26.6 (23.4–30)
Systolic BP (mmHg)	120 (110–130)	125 (112–132)
Diastolic BP (mmHg)	73 (67–80)	79 (73–86)*		1.15	1.0–1.3	0.04
HbA1c (%)	9.62 (2.8)	10.1 (1.8)
(mmol/mol)	81 (31)	87 (12)
Serum lipids(mmol/l)
Total cholesterol	4.72 (3.98–5.18)	5.19 (4.55–5.6)
LDL	2.41 (1.93–2.7)	2.87 (2.35–3.35)
Triglycerides	1.22 (0.58–1.86)	1.74 (1.31–1.98)
HDL	1.72 (1.39–2.03)	1.71 (1.35–2.05)
iGFR (ml/min/m^2)	114 (99–127)	109 (84–132)

Data shown as % (n), median (IQR) or mean (SD).

*p < 0.05.

BMI: body mass index; BP: blood pressure; iGFR: isotope glomerular filtration rate; eGFR: estimated glomerular filtration rate; GAD: glutamic acid decarboxylase; LDL: low density lipoprotein; HDL: high density lipoprotein.

P-values are for comparisons between the two groups by Wilcoxon signed-rank test for pairs of continuous variables and McNemar’s chi-square test for pairs of categorical variables.

The magnitude of risk ratio is presented as the odds ratio (OR) with 95% confidence interval (CI) and p-value.

Table 3: Clinical and laboratory characteristics in the clinic-level (CL) study in 2006 (n = 131) and 2015 (n = 231)

Factor	2006 n = 132	2015 n = 231	p-value
Ethnicity:			0.03
African	50 (66)	57.6 (133)
Indian	43.2 (57)	29.9 (69)
White	4.5 (6)	4.8 (11)
Mixed race	2.3 (3)	7.8 (18)
Gender:			0.94
Male	45.5 (60)	45.9 (106)
Female	54.5 (72)	54.1 (125)
Age (years)	27 (20–36)	22 (18–33)	0.02
Age at diagnosis (years)	16 (12–22)	13 (10–20)	0.001
Diabetes duration (years)	9 (5–15)	9 (4–16)	0.79
Presentation:			0.05
Ketoacidosis	32.6 (43)	43.3 (100)
Symptomatic	50 (66)	40.3 (93)
Abnormal glucose	10.6 (14)	6.1 (14)
Unknown	6.8 (9)	10.4 (24)
Anti-GAD positive*	58.2 (53)	72.1(163)	0.016
BMI (kg/m^2)	24.6 (21–28)	24.5 (21–28)	0.84
Systolic BP (mmHg)	120 (107–131)	126 (117–137)	< 0.001
Diastolic BP (mmHg)	74 (68–81)	75 (68–83)	0.37
HbA1c (%)^†	10.8 (2.9)	10.2 (2.5)	0.22
(mmol/mol)^†	95 (32)	88 (28)	0.22
Serum lipids (mmol/l):
Total cholesterol	4.8 (4.0–5.4)	4.3 (3.8–5.0)	0.001
LDL cholesterol	2.4 (1.9–3.0)	2.3 (1.8–2.8)	0.22
HDL cholesterol	1.7 (1.3–2.0)	1.4 (1.2–1.8)	< 0.001
Triglycerides	1.0 (0.7–1.7)	0.9 (0.6–1.4)	0.08
iGFR (ml/min/m^2)	111(90–129)	115(96–136)	0.17
Serum creatinine (µmol/l)	70 (58–82)	59 (50–73)	0.41
Urine albumin/creatinine ratio:^‡	1.2(0.5–3.3)	1.1 (0.4–4.4)	0.02
3–30 mg/mmol	18.9 (25)	22.5 (52)	< 0.001
> 30 mg/mmol	20.5 (27)	8.2 (19)	0.001
≥ 3 mg/mmol	39.7(52)	31.0 (71)	0.09
Retinopathy	15.2 (20)	15.6 (36)	0.99
MACE	1.5 (2)	2.2 (5)	0.99

Data shown as % (n), median (IQR) or mean (SD).

*n = 91 in 2006, n = 226 in 2015.

^†n = 131 in 2006, n = 230 in 2015.

^‡n = 129 in 2006, n = 229 in 2015.

BMI: body mass index; BP: blood pressure; iGFR: isotope glomerular filtration rate; eGFR: estimated glomerular filtration rate; GAD: glutamic acid decarboxylase; LDL: low density lipoprotein; HDL: high density lipoprotein; MACE: major adverse cardiovascular event.

P-values are for comparisons between the two groups by Dunn’s pairwise comparison with Sidak adjustment for continuous variables and Pearson’s chi-square or Fisher’s exact test for categorical variables.