Multi-ethnic differences in HbA_1c, blood pressure, and low-density-lipid cholesterol control among South Africans living with type 2 diabetes, after a 4-year follow-up

Figures & data

Table 1 Characteristics of study patients by ethnic grouping (2009 and 2013)

Characteristic	2009				2013
	Black African (n=112) 42.9%	Caucasian (n=66) 25.3%	Asian/Indian (n=68) 26.1%	Mixed ancestry (n=15) 5.7%	Black African (n=112) 42.9%	Caucasian (n=66) 25.3%	Asian/Indian (n=68) 26.1%	Mixed ancestry (n=15) 5.7%
Demographics
Age (years)	55±9.2	66.4±11.4	61.1±8.2	56.2±8.4	59±9.2	70.4±11.4	65.1±8.2	60.2±8.4
Female sex, n (%)	67 (59.8)	33 (50)	35 (51.5)	8 (53.3)	67 (59.8)	33 (50)	35 (51.5)	8 (53.3)
Clinical and laboratory measurements
Duration of diabetes (years)	9.6±6.5	13.9±7.7	12.3±6.2	10.4±6.4	13.6±6.5	17.9±7.7	16.3±6.2	14.4±6.4
CVD, n (%)	3 (2.7)	16 (24.2)	15 (22.1)	0	8 (7)	24 (36)	24 (35)	2 (13)
Stroke, n (%)	2 (1.8)	2 (3)	2 (2.9)	0	4 (3.6)	3 (4.5)	2 (2.9)	1 (6.7)
Retinopathy, n (%)	3 (2.7)	9 (13.6)	4 (5.9)	2 (13.3)	12 (10.7)	15 (22.7)	10 (14.7)	2 (13.3)
Neuropathy, n (%)	4 (3.6)	7 (10.6)	5 (7.4)	0	16 (14.2)	13 (19.7)	12 (17.6)	1 (6.6)
Nephropathy, n (%)	6 (5.4)	7 (10.6)	9 (13.2)	2 (13.3)	18 (16)	19 (28.7)	20 (29.4)	3 (20)
HbA1c (%)	8.7±2.4	8.1±1.7	8.3±2.1	9.2±2.4	8.8±2.2	8.5±1.6	8.5±1.8	9.6±2.2
SBP (mmHg)	134±17.4	135±21.2	132±15.3	129±17.5	141±21.5	143±23.5	133±20.3	131±20.1
DBP (mmHg)	80±9.9	76±10.8	79±11	73±8.6	75±10.8	72±10.8	70±12.7	69±9.1
Total cholesterol (mmol/l)	4.3±1.1	4.7±1.1	4.5±1.1	4.8±1.3	3.9±1	4.1±0.9	4.1±1.3	4.4±0.7
Triglycerides (mmol/L)	1.5±0.8	1.8±1	1.9±0.9	1.4±0.6	1.5±1.4	1.9±1.2	1.7±1	1.4±0.5
LDL cholesterol (mmol/L)	2.5±0.9	2.6±0.7	2.5±0.9	2.9±1.2	2.1±0.8	2±0.8	2.2±1	2.5±0.7
HDL cholesterol (mmol/L)	1.1±0.3	1.2±0.4	1.2±0.3	1.3±0.4	1.1±0.3	1.2±0.3	1.2±0.4	1.3±0.3
Glucose-lowering therapy
No antidiabetic medication, n (%)	1 (0.9)	0	2 (2.9)	0	0	0	1 (1.5)	0
Oral antidiabetic agents only, n (%)	29 (25.9)	14 (21.2)	24 (35.3)	4 (26.7)	18 (16.1)	14 (21.2)	19 (27.9)	0
Insulin only, n (%)	44 (39.3)	27 (40.9)	15 (22.1)	5 (33.3)	20 (17.9)	20 (30.3)	8 (11.8)	4 (26.7)
Combination therapy, n (%)	38 (33.9)	25 (37.9)	27 (39.7)	6 (40)	74 (66.1)	32 (48.5)	40 (58.8)	11 (73.3)
Metformin, n (%)	65 (58)	36 (54.4)	47 (69.1)	10 (66.7)	92 (82.1)	46 (69.7)	56 (82.4)	11 (73.3)
Cardiovascular therapy
Statins, n (%)	39 (34.8)	47 (71.2)	52 (76.5)	12 (80)	80 (71.4)	52 (78.8)	57 (83.8)	14 (93.3)
Antihypertensive drugs, n (%)	97 (86.6)	63 (95.5)	63 (92.6)	13 (86.7)	105 (93.8)	63 (95.5)	61 (89.7)	15 (100)
ACE inhibitors or ARBs, n (%)	84 (75)	54 (81.8)	54 (79.4)	10 (66.7)	83 (74.1)	55 (83.3)	58 (85.3)	11 (73.3)
Antiplatelet drugs, n (%)	49 (43.8)	34 (51.5)	37 (54.4)	8 (53.3)	46 (41.1)	34 (51.5)	34 (50)	5 (33.3)

Abbreviations: ACE, angiotensin converting enzyme; CVD, cardiovascular disease; HbA_1c, glycated hemoglobin; SBP, systolic blood pressure; DBP, diastolic blood pressure; LDL, low-density lipoprotein; HDL, high-density lipoprotein; ARBs, angiotensin-receptor blockers.

Table 2 Ethnic differences in HbA_1c-target achievement, oral hypoglycemic and insulin usage among study patients

Ethnic group	Patients reaching HbA1c <7%			Patients prescribed oral hypoglycemic agents			Patients prescribed insulin
	2009	2013	Change	2009	2013	Change	2009	2013	Change
Black African	25%	19.6%	–5.4%	59.8%	82.1%	22.3%	73.2%	83.9%	10.7%
Caucasian	27.3%	10.6%	–16.7%	59.1%	69.7%	10.6%	78.8%	78.8%	0
Asian/Indian	36.8%	17.6%	–19.2%	75%	86.8%	11.8%	61.8%	70.6%	8.8%
Mixed ancestry	13.3%	13.3%	0	66.7%	73.3%	6.6%	73.3%	100%	26.7%
All groups	25.4%	15.5%	–9.9%	65.1%	78%	12.9%	71.8%	83.3%	11.5%
All groups (weighted)	28%	16.5%	–11.5%	64%	79.7%	15.7%	71.6%	80.1%	8.5%

Abbreviation: HbA_1c, glycated hemoglobin.

Table 3 Ethnic differences in BP-target achievement and ACE inhibitor/ARB usage among study patients

Ethnic group	Patients reaching BP <140/80 mmHg			Patients treated for hypertension			Patients prescribed ACE or ARB inhibitors
	2009	2013	Change	2009	2013	Change	2009	2013	Change
Black African	26.8%	42%	15.2%	86.6%	93.8%	7.2%	78.6%	74.1%	–4.5%
Caucasian	28.8%	43.9%	15.1%	95.5%	95.5%	0	81.8%	83.3%	1.5%
Asian/Indian	33.8%	63.2%	29.4%	92.6%	89.7%	–2.9%	82.4%	83.8%	1.4%
Mixed ancestry	53.3%	66.7%	13.4%	86.7%	100%	13.3%	66.7%	73.3%	6.6%
All groups	35.9%	49.6%	13.7%	90.3%	94.7%	4.4%	77.4%	78.6%	1.2%
All groups (weighted)	46%	49.4%	3.4%	90.4%	93.5%	3.1%	79.7%	78.9%	–0.8%

Abbreviations: BP, blood pressure; ARB, angiotensin-receptor blocker; ACE, angiotensin converting enzyme.

Table 4 Ethnic differences in LDL-C target achievement and statin usage among study patients

Ethnic group	Patients reaching LDL-C <1.8 mmol/L (with CVD/stroke)			Patients reaching LDL-C <2.5 mmol/L (no CVD/stroke)			Patients prescribed statins
	2009	2013	Change	2009	2013	Change	2009	2013	Change
Black African	15.4%	54.5%	39.1%	51.1%	71%	19.9%	34.8%	71.4%	36.6%
Caucasian	20%	44%	24%	49.5%	90.2%	40.7%	71.2%	78.8%	7.6%
Asian/Indian	25%	48%	23%	45.7%	65.1%	19.4%	76.5%	83.8%	7.3%
Mixed ancestry	0	33.3%	33.3%	50%	50%	0	80%	93.3%	13.3%
All groups	15.1%	45%	29.9%	49.1%	72.7%	23.6%	65.4%	81.8%	16.4%
All groups (weighted)	20%	46.9%	26.9%	49%	71.7%	22.7%	57.5%	77.8%	20.3%

Abbreviations: LDL-C, low-density-lipoprotein cholesterol; CVD, cardiovascular disease.

Figure 1 Ethnic differences in achievement of glycemic, BP, and lipid targets among study patients.

Abbreviations: BP, blood pressure; HbA_1c, glycated hemoglobin; LDL-C, low-density-lipoprotein cholesterol.