Diabetic nephropathy in Africa: A systematic review

Table 4 Risk factors for chronic kidney disease in people with diabetes

Ref.	Country	Sample size	Type of diabetes	Diagnostic criteria for CKD	Risk factor	Measure of association		Factors adjusted for	Comments
						Effect size	P-value
Motala et al[37], 2001	South Africa	219	T1DM and T2DM	Persistent proteinuria	Not assessed
Elbagir et al[26], 1995	Sudan	128	Insulin-treated	Proteinuria	Age		P = 0.006
					Duration of diabetes		P = 0.003
					Systolic BP		P = 0.0001
					Diastolic BP		P = 0.001
					Serum cholesterol		P < 0.05
Sobngwi et al[44], 1999	Cameroon	64	T1DM and T2DM	Proteinuria	Duration of diabetes		P = 0.04
					Diastolic BP		P = 0.01
Katchunga et al[30], 2010	DR Congo	98	T2DM	MDRD (corrected for Blacks); CKD stage ≥ 1 according to the National Kidneyfoundation	Hypertension	aOR: 2.49 (0.98-6.34)	P = 0.04	Age, duration of diabetes, BMI
Choukem et al[22], 2012	Cameroon	420	T2DM	Proteinuria (30 mg/24 h)	Systolic BP	aOR: 1.45 (1.15-1.84)	P = 0.006
					Diastolic BP	aOR: 1.33 (1.06-1.66)	P = 0.026
					Pulse pressure	aOR: 1.35 (1.06-1.71)	P = 0.0007
					Mean arterial pressure	aOR: 1.42 (1.13-1.78)	P = 0.006
Keeton et al[31], 2004	South Africa	59	T2DM	Urine Albumin-to-Creatinine Ratio (no detail)	High entry serum creatinine		P < 0.006		These are risk factors for death from chronic renal failure (compared with the patients who were still alive at follow-up)By the end of study 47 of the 59 patients had died; the cause of death not established in 2 patients. Death was due to chronic renal failure in 17 cases
					BMI < 28		P < 0.003
					Severe retinopathy		P < 0.002
					Mean glucose level of > 14 mmol/L		P < 0.035
Pruijm et al[39], 2008	Seychelles	1218	All types	Microalbuminuria: Urine Albumin-to-Creatinine Ratio 3.4-33.9 mg albumin/mmol creatinine	Not assessed				Risk factors were investigated in the whole study population in both diabetics and non-diabetics
Alebiosu[16], 2003	Nigeria	342	T1DM and T2DM	Persistent proteinuria	Not assessed
Bouaziz et al[20], 2012	Tunisia	73	T2DM	Microalbuminuria: < 2.8 g/mol for women and < 2.3 g/mol for men	Family history of nephropathy		P = 0.0289		Comparison of T2DM patients with nephropathy with those without nephropathy
					Smoking		P = 0.0056
					Insulin therapy		P = 0.0310
					Glitazones therapy		P = 0.0115
					Anti-hypertensives (not ACE inhibitor)		P < 0.0001
					Lipid-lowering agents		P < 0.0001
Ajayi et al[15], 2014	Nigeria	65	T2DM	MDRD: eGFR ≤ 60 mL/min per 1.73 m2	Not assessed
Levitt et al[32], 1997	South Africa	243	T2DM and T1DM	Urine Albumin-to-Creatinine Ratio > 3.4 mm/mmol	Not assessed
				and Persistent proteinuria (for at least 3 consecutive visits)
Majaliwa et al[34], 2007	Tanzania	99	T1DM	Proteinuria (no detail)	Missing insulin doses		P = 0.045	Not available
Marshall et al[36], 2013	Rwanda	286	T1DM	Microalbuminuria: Urine Albumin-to-Creatinine Ratio = 30-299 mg/g	Age (increase)	aOR: 0.86, 95%CI: 0.77-0.96	P = 0.009	Each variable is adjusted for the others	These are risk factors of microalbuminuria. There was no factor associated to macroalbuminuria
					Duration of diabetes (one year increase)	aOR: 0.86, 95%CI: 0.77-0.96	P = 0.008
					Diastolic BP (increase)	aOR: 0.86, 95%CI: 0.77-0.96	P = 0.004
					HBA1c (increase)	aOR: 0.86, 95%CI: 0.77-0.96	P = 0.047
Alebiosu et al[18], 2003	Nigeria	465	T2DM	Proteinuria and eGFR (no detail)	Hypertension, left ventricular hypertrophy, stroke and myocardial infarction were more frequent in advanced stages of nephropathy	Not available	P < 0.05	Not available	Patients with advanced stages of nephropathy (IV and V) were compared with those with stages ≤ III
Gill et al[28], 2005	South Africa	88	T1DM	Persistent dipstick proteinuria	Not assessed
Djrolo et al[24], 2001	Benin	152	T1DM and T2DM	Proteinuria (no detail)		Not available	Not available	Not available	Proteinuria was more frequent in insulin-treated patients compared those on oral antidiabetic treatment. The prevalence of proteinuria also increased with the duration of diabetes
Rotchford et al[43], 2002	South Africa	253	T1DM and T2DM	Microalbuminuria > 2.5 mg/mmol in men or 3.5 mg/mmol in women	Duration of diabetes > 10 yr	4.19 (1.93-9.10)	< 0.001	Model contains duration of diabetes, BMI, HbA1c, age andhypertension
					BMI > 33	0.27 (0.08-0.48)	0.002
					HbA1c > 14%	4.69 (1.65-13.3)	0.004
					Hypertension	2.11 (1.07-4.17)	0.031
Rissassi et al[42], 2009	DR congo	181	T1DM	Microalbuminuria: Urine Albumin-to-Creatinine Ratio = 30-299 mg/gMacroalbuminuria: Urine Albumin-to-Creatinine Ratio ≥ 300 mg/g	Duration of diabetes > 5 yr	4.1 (1.9-8.4)		No precision
					Age > 18 yr	2.9 (1.3-6.2)
					HbA1c > 10%	2.6 (1.1-6.4)
Rahlenbeck et al[40], 1997	Ethiopia	170	T1DM and T2DM	albuminuria: > 30 mg/L	Duration of diabetes	Beta = 0.061, SE = 0.018 for T1DM	< 0.001	Hypertensive patients excluded
					Systolic blood pressure	Beta = 0.027, SE = 0.005 for T1DM	< 0.001
Wanjohi et al[45], 2002	Kenya	100	T2DM	Proteinuria ≥ 20mg	None identified
Nambuya et al[38], 1996	Uganda	252	T1DM and T2DM	Proteinuria (no detail)	None assessed
Rasmussen et al[41], 2013	Zambia	101	T1DM and T2DM	Microalbuminuria: ACR = 3.5-35.0 for women and 2.5-25.0 mg/mmol for menMacroalbuminuria were ACR> 35.0 for women and > 25.0 for men	None assessed
Bentata et al[19], 2013	Maroc	72	T1DM	End-stage renal disease: eGFR < 15 mL/min	Hemoglobin blood (per 1 g/dL decrease)	3.18 (1.47-6.87)	0.003	No precision	These are independent risk factors for ESRD in type-1 diabetes patients with diabetic nephropathy
					Diastolic blood pressure (per 1 mmHg increase)	1.15 (1.04-1.27)	0.006
Gill et al[27], 2008	Ethiopia	105	T1DM and T2DM	Nephropathy: ACR> 25.0 mg/mmol and retinopathy presentMicroalbuminuria: ACR> 2.5 and < 25.0 mg/mmol in men and > 3.5 and< 25.0 mg/mmol in women	None assessed
Bouzid et al[21], 2011	Tunisia	689	T2DM	Renal failure: creatinine clearance < 60 mL/min (Cockroft-Gault)	Older age	Not provided	< 0.00001
					Hypertension		< 0.00001
					Long duration of diabetes		< 0.001
					Higher BMI		0.02
					Dyslipidemia		0.01
Janmohamed et al[29], 2013	Tanzania	369	T1DM and T2DM	CKD: eGFR < 60 mL/min per 1.73 m2 (Cockroft-Gault) or microalbuminuria (> 20 mg/L) or overt proteinuria	Older age	1.03 (1.00-1.05)	0.03	Adjustment made, but no precision
Danquah et al[23], 2012	Ghana	671	T2DM	Proteinuria ≥ 20mg/l	Not assessed
Lutale et al[33], 2007	Tanzania	244	T1DM and T2DM	Abnormal proteinuria: AER > 20 μg/min	Duration of diabetes	0.090 (0.049- 0.131)	< 0.0001	Predictors in the model: diabetes duration, Systolic BP, age, serum creatinine	Measure of association is β
					Elevated systolic blood pressure	0.012 (0.003-0.021)	0.010
					Elevated serum creatinine	0.011 (0.002- 0.020)	0.016
Worku et al[46], 2010	Ethiopia	305	T1DM and T2DM	Proteinuria (no detail)	Duration of diabetes	Not provided	0.001
					T2DM on insulin		0.018
Makulo et al[35], 2010	DR Congo	81	No precision	Microalbuminuria: ACR 30-299 mg/gMacroalbuminuria: ACR ≥ 300 mg/gRenal failure: eGFR < 60 mL/min per 1.73 m2	Not assessed
Eghan et al[25], 2007	Ghana	109	T1DM and T2DM	Microalbuminuria: ACR 30-300 mg/g	Duration of diabetes		0.04		The associations were assessed by comparing patients with and without microalbuminuria
					Serum creatinine		0.05
					Blood urea nitrogen		0.01
					Urine potassium		0.0061
Alebiosu et al[17], 2004	Nigeria	162	T2DM	No precision	Duration of diabetes		< 0.05		The study assessed the predictors of diabetic nephropathy comparing T2DM patients with and without nephropathy
					Serum total cholesterol		< 0.05
					Alcohol > 30 mg/d		< 0.05
					Peripheral vascular disease		< 0.05
					Stroke		< 0.05

CKD: Chronic kidney disease; BMI: Body mass index; ACR: Albumin-to-Creatinine Ratio; T1DM: Type 1 diabetes mellitus; T2DM: Type 2 diabetes mellitus; eGFR: Epidermal growth factor receptor.