Microalbuminuria and Associated Factors in Diabetics at the CNHU-HKM of Cotonou ()
1. Introduction
Developing countries are faced with the emergence of non-communicable diseases (NCDs), which have very significant consequences in terms of morbidity and mortality. However, NCDs (cardiovascular diseases, type 2 diabetes, cancers, etc.) are on the rise all over the world, including in the countries of the South, in terms of incidence and mortality. Among the NCDs is diabetes, which is characterised by chronic hyperglycaemia, i.e. an excess of sugar in the blood and therefore an excessively high level of glucose (blood sugar). The prevalence of diabetes is increasing worldwide, especially in developing countries. Between 2000 and 2016, premature mortality attributable to diabetes increased by 5% in low-income countries (WHO) [1] . Benin, a developing country, has not been left out of this epidemic trend. According to a national survey in 2001, the prevalence of diabetes in Benin was 1.01%, but this figure rose to 2.6% in 2008 according to the STEPS survey [2] and then to 4.5% in 2015 and 5.1 in 2016 [3] . There are two main types of diabetes: type 1 diabetes which affects about 10% of diabetics and type 2 diabetes which affects 90%. Other types of diabetes affect the remaining 2% (MODY, LADA or diabetes secondary to certain diseases or medication). Several complications can occur during diabetes, such as diabetic nephropathy. Diabetic nephropathy (DN) is the leading cause of end-stage renal disease worldwide [4] . In type 2 diabetics, it begins with microalbuminuria and, as in the general population, is primarily associated with an increased cardiovascular risk. In view of these observations, in a population characterised by a high rate of illiteracy and a low socio-economic level, the present study aims to determine the prevalence of microalbuminuria in diabetics and the associated factors in the Endocrinology-Metabolism-Nutrition Department of the CNHU-HKM of Cotonou in 2021.
2. Study Methods
The study was a cross-sectional and analytical study that took place from September 23 to December 23, 2021 and included diabetic patients followed up in the endocrinology department of the CNHU-HKM of Cotonou for the management of their diabetes during the study period and who gave their consent. Diabetic nephropathy is the kidney damage of diabetes mellitus. The first stage of diabetic nephropathy is microalbuminuria. The variables studied were age, sex, place of residence, level of education, occupation, religion, marital status, ethnicity, duration of diabetes, glycaemic control, dyslipidaemia and complications of diabetes. The data were collected on the Kobo Collect software and then processed and analysed using R. version 3.6.1. The comparison of proportions and percentages was carried out with the Chi2 test or Fisher’s exact test, depending on the case. A p < 0.05 was considered statistically significant. The threshold for statistical significance was 5%.
3. Results
In our sample of 145 type 2 diabetics included in the study, 44 patients had positive microalbuminuria.
3.1. Socio-Demographic Characteristics
Our study population is made up of both sexes and ranges in age from 26 to 85 years.
Most of the subjects were in the age group 56 - 66 years. The mean age of the study population was 59.74 ± 8.83 years with extremes ranging from 26 to 85 years. The median class was 56 - 70 years.
There was a predominance of women (57.9%) compared to men (2.14%). The majority of our patients, regardless of sex, were between 46 and 76 years old (Table 1).
Table 1. Socio-demographic characteristics of diabetic patients followed up in Endocrinology-Metabolism-Nutrition at the CNHU-HKM of Cotonou during the study period (N = 145).
3.2. Characteristic of Diabetes
All patients had type 2 diabetes and 57.9% of these patients had suffered from diabetes for more than 5 years. The majority of patients (90.3%) were being treated with oral antidiabetic drugs. Diabetes imbalance was found in 69.7% of the patients (Table 2).
3.3. Vascular Risk Factors in Diabetic Patients
Hypertension was present in 71.7% of diabetic patients, dyslipidaemia in 55.9% and stroke in 5.5%. The frequency of patients taking alcoholic beverages at least once a month was 15.2% and that of those who occasionally used tobacco was 2.8.
After recruitment, seventy-seven patients were overweight (53.1%) and 26 patients (17.9%) were obese. The average waist circumference of our patients was 93 cm. The majority of patients (70.8%) were abdominally obese.
Hypertension was present in 71.7% of patients, most of whom were women (Table 3).
3.4. Diabetes-Related Complications
During recruitment, the most recorded complications included neurological complications (26.4%), followed by ocular complications (21.4% of cases).
Table 2. Distribution of patients according to type of diabetes, treatment, length of time and diabetes control in the Endocrinology-Metabolism-Nutrition Department of the CNHU-HKM, Cotonou/Benin, 2021.
HbA1c = Glycated haemoglobin.
3.5. Presentation of the Population with Microalbuminuria
Of the 145 patients surveyed, 44 had microalbuminuria, a prevalence of 30.3%.
The number of patients with positive microalbuminuria was 44 (24 women and 20 men). The majority of patients with positive microalbuminuria were in the 56 - 66 age group.
The majority with positive microalbuminuria were also hypertensive (36/44 patients).
The most identified complications in diabetics with positive microalbuminuria were dyslipidaemia (40.7%), neuropathy (27.3%), nephropathy (18.2%) and retinopathy (29.5%) (Table 4).
Factors associated with microalbuminuria in patients followed in Endocrinology Metabolism Nutriton at the CNHU-HKM of Cotonou in 2021.
3.6. Univariate Analysis
No statistically significant relationship was observed between microalbuminuria and gender (p = 0.58), education level (p = 0.16), marital status (p = 0.09), and employment status (p = 0.09). However, there was a statistically significant relationship between microalbuminuria and age (p < 0.001). Indeed, 41.1% of patients aged over 59 years had microalbuminuria compared to 10% of those aged under 59 years (Table 5).
Table 3. Vascular risk factors identified in diabetic patients followed at the Endocrinology-Metabolism-Nutrition Department of the CNHU-HKM of Cotonou during the study period (N = 145).
Table 4. Distribution of patients according to diabetes-related complications.
Table 5. Relationship between microalbuminuria and socio-demographic characteristics in patients followed up in Endocrinology Metabolism Nutrition at the CNHU-HKM of Cotonou in 2021.
No statistically significant relationship was observed between microalbuminuria and Retinopathy (p = 1.00), Diabetic Nephropathy (p = 0.07), Peripheral Neuropathy (p = 0.09), and Stroke (p = 0.25). Table 6 shows the relationship between microalbuminuria and diabetic complications (Table 7).
3.7. Biological and Clinical Parameters
No statistically significant relationship was observed between microalbuminuria and diabetes age (p = 0.71), however, there was a statistically significant relationship between microalbuminuria and glycaemic control: HbA1c > 7% (p = 0.03), dyslipidaemia (p = 0.01), hypertension (p < 0.001) and erectile dysfunction (p < 0.001) (Table 7).
3.8. Multivariate Analysis
Table 8 shows the univariate and multivariate analysis of the occurrence of microalbuminuria. In multivariate analysis, after adjustment for education level, marital status, occupational status, diabetic nephropathy, peripheral neuropathy and erectile dysfunction, microalbuminuria was significantly associated with age (p = 0.00), glycaemic control (p = 0.01), dyslipidaemia (p = 0.03) and hypertension (p < 0.001). Patients over 59 years of age were 5.3 times more likely to have
Table 6. Relationship between microalbuminuria and diabetic complications in patients followed up in Endocrinology-Metabolism-Nutrition at the CNHU-HKM of Cotonou in 2021.
Table 7. Relationship between microalbuminuria and biological and clinical complications in patients followed in Endocrinology Metabolism Nutrition at the CNHU-HKM of Cotonou in 2021.
Table 8. Factors associated with microalbuminuria in patients followed in Endocrinology Metabolism Nutrition at the CNHU-HKM of Cotonou in 2021.
microalbuminuria than patients under 59 years of age. Similarly, patients with glycaemic imbalance were about twice as likely to have microalbuminuria compared to those without. Furthermore, the risk of developing microalbuminuria was 2.2 times greater in patients with dyslipidaemia. The risk of developing microalbuminuria in patients with hypertension was 7.1 times that of patients without hypertension.
4. Discussion
The prevalence of microalbuminuria in diabetics in our present study was 30.3%. Several authors in their studies have come to a similar result.
During our study, we counted 145 type 2 diabetic patients with a predominance of women represented at 57.93%. This predominance of women was also found by Djrolo et al. 56.1% [3] , Agboton et al. (58.6%) in Benin [5] and also by Yamego et al. [6] in Senegal.
They had a mean age of 59 years with extremes ranging from 26 to 85 years. This average is similar to that of Thaleb et al. [7] in Lebanon (56 years) and Yamego et al. [6] in Senegal (58 years).
This 30.3% prevalence of microalbuminuria is far from those found by Djrolo (39.2%) [3] Monabeka et al. [8] in Congo (37.9%) and by Yameogo et al. [6] in Senegal (36.8%) in 2012. However, it is lower than that found by Charfi et al. in Tunisia (2010) who found a prevalence of 15% [9] . This difference would be due to the fact that their sample size was small and their study was retrospective. Also, this prevalence among type 2 diabetics varies between countries and studies. This would mean that diabetic patients in our series benefit from early management once in the microalbuminuria stage which prevents progression to the advanced stages.
In addition, microalbuminuria is significantly associated with hypertension, diabetes imbalance in some studies such as Djrolo in Benin [3] , Yamego et al. in Senegal [6] . Our study also shows that type 2 diabetics with microalbuminuria have poor glycaemic control compared to those without microalbuminuria.
From the analysis of these results, we can deduce that microalbuminuria is associated with age, poor glycaemic control revealed by an HbA1c level above 7% as reported in several studies [6] [10] [11] [12] [13] . This is especially true as we found in our series an association between glycated haemoglobin and microalbuminuria in type 2 diabetics (OR = 1.6; 95% CI: 1.1 - 4.7; p = 0.01).
Nephropathy is associated with a particular dyslipidemia, by increase of lipoprotein(a) linked to renal loss of apoCII (LPL activator), and accumulation of apoCII (LPL inhibitor). Boufaida et al. 2016 (Morocco) [14] noted in their studyconducted in Morocco a significant relationship between dyslipidemia (p = 0.008) and microalbuminuria in diabetics. Dyslipidemia (p = 0.03) is also associated with microalbuminuria in diabetics in our study.
The determinants of microalbuminuria can be divided into two factors non-modifiable factors (age) and modifiable factors (diabetes control, hypertension, and dyslipidaemia) [15] .
Multivariable analysis enabled us to identify an association between microalbuminuria and age: p = 0.00, hypertension: p = 0.00, diabetes control: p = 0.01, dyslipidaemia p = 0.03. These different factors have been identified in many other studies by various authors such as the study by Varghese et al. [15] , Yamego et al. [6] , Monabeka et al. [8] . In these studies, the main factors found were age, hypertension, unbalanced diabetes and the length of time diabetes had been present. In our study, however, statistical analysis revealed no significant association between microalbuminuria and the duration of diabetes.
5. Conclusion
At the end of this study which focused on microalbuminuria and associated factors in diabetics followed at the University Clinic of Endocrinology Metabolism Nutrition of the CNHU-HKM of Cotonou, Benin in 2021, it appears as follows. The prevalence of microalbuminuria is high 30.3% in the diabetics included in the study. Factors associated with microalbuminuria are: age, occupation, hypertension, unbalanced diabetes, erectile dysfunction, dyslipidaemia, the determination of these risk factors is essential for the identification of patients at risk and management.