This study was conducted in the city of Kisangani, Tshopo province, which is located in the Northeast of the Democratic Republic of the Congo (DRC). Seven healthcare facilities, including two tertiary level hospitals: the University Clinics of Kisangani (CUKIS) and the Cinquantenaire Hospital of Kisangani (HCK), and five secondary level, including main general reference hospitals (HGR); the HGR of Makiso-Kisangani, HGR of Kabondo, HGR of Tshopo, HGR of Mangobo, and HGR of Lubunga. The study population consisted of patients admitted to the internal medicine departments of these seven healthcare facilities, while the target population consisted of all patients diagnosed as diabetic.

A facility-based descriptive and cross-sectional study was employed by reviewing patients’ documents admitted from 2018 to 2021 in selected Health facilities in Kisangani city. Data collection (documentary analysis) was conducted during the period from August 15 to November 15, 2023.

Convenience sampling technique targeting referral healthcare facilities at the secondary and tertiary levels in Kisangani city with high patient capacity and technical facilities was employed in this study. These healthcare facilities receive all referral cases in the city and have sufficient capacity for proper patient care. At the healthcare facility level, a comprehensive study of all diagnosed diabetic patients was conducted during the study period. Case selection in the facilities was made according to whether the patient’s file contained all the required information, including the diagnosis of diabetes mellitus, anthropometric parameters and the prescription of hygiene and dietary measures, which were consulted during the study period.

Documentary review techniques were used for data collection. The patient files were consulted and, in some cases, missing information was searched in the patient register. The variables studied were socio-demographic profile of the patients, namely age, sex, weight, height, and main activity. In addition, the body mass index (BMI) of the patients was calculated. Pathologies associated with diabetes mellitus, such as a family history, hygiene and dietary measures, were also recorded. All data collected were recorded in a dedicated form.

The collected data were encoded in Microsoft Excel 2007 and imported into Statistical Package for the Social Sciences (SPSS 20) software for analysis. The sample was described using proportions for categorical variables and the mean (±SD) for quantitative variables that showed a symmetrical distribution. For all records whose type of diabetes was not specified, the patients under 40 years of age were classified as type 1 diabetic, and those aged 40 years or older as type 2 diabetic. Statistical inferences were made using Pearson’s chi-square and Fisher’s Exact tests for categorical variables for significance level of P < 0.05, according to the conditions of their applications. The results were presented in tables and graphs.

Access to patient files was obtained after receiving permission from the heads of the selected hospitals through ethical approval request after a detailed explanation of the research methodology and the significance of the study. All data were collected anonymously and were solely used for research purposes.

The results of this study are limited to patients who consulted the internal medicine departments of HGRs and CUKIS, whose files were available in the archives between the years 2018 and 2021.

Table 1 shows demographic parameters of the patients studied. The result reveals that the majority of the DM patients were male (56.4%), while more than three-forth had a family history of DM. Among the patients, those diagnosed with type 2 diabetes were accounted for 83.4% of cases. In 68.8% of patients, the disease had been diagnosed less than 5 years ago. The patients’ average body mass index (BMI) was 27.7 ± 5.4 kg/m², while their average age was 55.3 ± 13 years. The research indicated that the mean body temperature was 37.5 ± 1.3˚C. Additionally, the mean blood glucose concentration was recorded at 263 ± 109.8 mg/dl. Only 155 patients (41.4%) benefited from the lifestyle and dietary measures (HDM) and difference was significant for all measures (P < 0.05).

® = Pearson chi-square test; © = Fisher’s Exact tests; * = Pastor, farmer, resourceful, taxi driver; ** = Retinopathy, diabetic foot and neuropathy; MHD = Hygiene and dietary measures.

In relation to the prescribed measures, 149 of the 155 patients, representing 96.1%, were advised to refrain from consuming sweet-flavored items, including cookies, candies, chocolates, and sugary beverages. Furthermore, 79.4% of the patients were prescribed a low-sodium diet, and 63.2% were advised to engage in regular physical exercise, defined as at least three sessions per week, each lasting thirty minutes. Out of 155 patients, merely 14, representing 9.0%, were advised to limit their intake of foods characterized by a high glycemic index (GI). The result revealed that the diet prescriber did not clearly define which specific foods were included in this recommendation.

The results of the prevalence of diabetes mellitus among patients admitted to the internal medicine departments of selected healthcare institutions from 2018 to 2021 are presented in Table 2 .

The prevalence/magnitude/frequency of diabetes mellitus was studied over a period from 2018 to 2021, during which 6013 patients were admitted to the internal medicine department of various healthcare institutions. Among them, 374 (6.2%) cases of diabetes DM were diagnosed. The percentage varied over the years, starting at 4.2% in 2018, increasing to 8.0% in 2020, and subsequently decreasing to 7.1% in 2021. The frequencies/prevalence observed varied considerably across the healthcare facilities over the four-year study period (P < 0.05): specifically, the rate was 9.4% at the university clinics, 7.7% at the Makiso-Kisangani General Hospital, and 6.7% at the Cinquantenaire Hospital in Kisangani. Conversely, the Kabondo HGR exhibited a low prevalence rate of merely 3.6%.

® = Pearson chi-square test; GRH = General Reference Hospital; DS: Diabetes mellitus; HCK: Hospital of Cinquantenaire Kisangani; CUKIS: University Clinics of Kisangani.

The evolution of cases of diabetes mellitus over the years in Kisangani is presented in Figure 1 and Figure 2 .

The analysis reveals an alarming trend: cases of diabetes are increasing steadily each year. In 2018, there were 4.2%, which increased to 5.7% in 2019, 8% in 2020 and finally to 7.1% in 2021.

The data regarding gender of the study subjects reveals that more than half of the DM patients were male (56.4%) and the difference between the two sexes was significant (P < 0.001). This finding agrees with the report of Yakusu et al. [15] , where 66.2% of DM patients were reported to be male at CUKIS. However, the current finding contradicts with the results of Risasi Etutu Junior et al. [3] at the Kinshasa provincial hospital, where 60% of cases were female. The International Diabetes Federation [16] indicates that the number of male diabetic patients is slightly higher than that of women, which agrees with this result. The average age of the patient was 55.3 ± 13 years, which agrees with the average age of 56.3 years reported by Yakusu et al. [15] among diabetics in CUKIS. This result can be explained by the pathophysiology of DM, a chronic disease that often manifests clinically after the age of forty. In addition, 3/4 of the patients had a family history of DM, and most cases were type 2 diabetes mellitus, with type 1 DM representing only 16.3% of patients (P < 0.001).

It is well known that the proportion of type 1 diabetes mellitus (T1DM) cases often does not exceed 25% of diabetes mellitus cases [17] . However, we recognize that classifying as T1DM if patients were under 40 and type 2 diabetes mellitus (T2DM) if 40 or older is imprecise. In fact, for some patients, the healthcare staff did not document the specific DM type at all, forcing us to rely on age as a proxy. This approach may have led to misclassification, potentially affecting our analyses of prescription patterns and dietary recommendations, which differ between T1DM and T2DM. We therefore consider this as a key weakness of this study and recommend targeted training for clinicians to ensure that DM type is recorded accurately at admission.

The average Body Mass Index of the patients was 27.7 kg/m² (16.4 to 44.9) of indicating that the majority of patients were overweight or obese. It has been reported that overweight and obesity are risk factors for DM [18] . The mean blood glucose level of the patients was 263 ± 109.8 mg/dl. Although these measurements were taken at different times of the day, it reflects persistent hyperglycemia in diabetic patients. Chronic hyperglycemia is a key feature of impaired glycemic control. This condition puts patients at increased risk of metabolic and vascular complications, such as neuropathy, retinopathy, cardiovascular disease, and renal damage [19] [20] . High and uncontrolled blood glucose levels can lead to structural and functional alterations of blood vessels, nerves, and other tissues, thus contributing to the progression of diabetic complications [21] [22] . The comorbidity of diabetes mellitus and hypertension was 36.6% and 42.2% for malaria and infections.

The previous studies reported that about 20% DM patients had cardiac disease, whereas 16.3% had a nephropathy. A comorbidity rate of diabetes mellitus and hypertension of 21.1% and 39.6% for infections was also reported [10] .

The prevalence of Diabetic Mellitus varies significantly among the five health facilities surveyed in Kisangani, ranging from 3.6% at HGR Kabondo, 4.7% at HGR Tshopo, 6.8% at Cinquantenaire Hospital of Kisangani, 7.7% at HGR Makiso-Kisangani to 9.4%) at CUKIS (P < 0.008). This inter-facility variation likely reflects differences in patient socioeconomic status (higher income patients tend to frequent CUKIS, HGR Makiso-Kisangani or Cinquantenaire Hospital of Kisangani, where fees and perceived quality and availability of specialised care are higher) as shown in Table 2 .

The overall hospital-based prevalence of 6.2% in this study was lower than 8.4% for DM and 18.0% for prediabetes reported by Nantakumar et al. [9] in Kinshasa. However, Nantakumar et al. conducted a community-level screening of diabetes mellitus in which assymptomatic cases and those who never visited a clinic were captured. By contrast, our study included only patients already admitted to hospitals, undercounting other categories. It then appears that the number of asymptomatic diabetics is higher in the general population than in those who consult health structures. Therefore, it is a dangerous situation in terms of health, because uncontrolled hyperglycemia for a long period predisposes the patient to short- and long-term complications. Since these people do not benefit from the necessary early medical and hygiene-dietary interventions. However, Muyer et al. [7] documented a 4.8% DM prevalence in Kisantu, a peri-urban city of Bas Congo, despite using a community-level screening. We believe that environmental and lifestyle factors, such as more sedentary habits and greater consumption of fatty or refined and sugary foods in urbanised Kinshasa, may explain why their prevalence (8.45%) differs from that of Kisantu (4.8%).

The higher number of cases 8.0% and 7.1% were recorded in 2020 and 2021 respectively. In addition, Figure 1 shows that the number of diabetes cases increased each year, with 63 cases in 2018, 82 in 2019, 104 in 2020 and 125 cases in 2021. A previous study conducted at CUKIS revealed a hospital prevalence of DS of 4.1% [8] . However, in this study, the frequency of cases found is twice as high (9.4%) in the same healthcare facility. The situation in Kisangani is consistent with data from Saeedi et al. [2] and the International Diabetes Federation [16] , which shows an increasing trend in cases of DM worldwide, estimated at 108 million in 1980, 422 million in 2014, 463 million in 2019, and possibly reaching 578 million in 2030 [2] . In Africa, between 1980 and 2014, the number of reported diabetes mellitus cases increased from 7 million to 25 million. This number is estimated to reach 34.2 million by 2040. It is predicted that 63% of cases of diabetes mellitus remain undiagnosed [16] . This increase in cases in the hospital incidence of diabetes mellitus found in this study can be attributed to population growth, nutritional transition, sedentary lifestyle, genetic factors, and population aging. These data highlight the critical importance of taking preventive measures and effective management of this growing disease.

The result of the study reveals that the lifestyle and dietary measures were prescribed in only 41.4% of patients. In the management of the DM, hygiene and dietary measures are recommended for all patients; however, in the DRC, these measures are based on principles adapted to local realities while being inspired by international recommendations. In particular, limiting the consumption of fast sugar and sugary foods, promoting the consumption of complex carbohydrates and dietary fiber, controlling fat and protein intake, balanced meal distribution, and integrating physical activity and stress management [17] . However, the prescribers did not comply with this principle, some mentioned only hygieno-dietetic measures in the patient’s file without any detail, and others mentioned some food and physical activity on the patient sheet. This could hamper the patient’s support for the prescribed regime, since he did not have clear explanations on the principles of the regime and his importance in the management of his illness. We then propose that the service provider be trained in dietetic management to improve prescription. In addition, as some hospitals do not have nutritionists, it is therefore important that the government can hire nutritionists in all hospitals so that they ensure dietary advice for patients. It is also possible that some patients received dietary advice verbally, but nothing was recorded in the medical file, which would have led to the patient being considered as not having received dietary advice. Indeed, it has been established that the pharmacological approach in glycemic control in diabetics is more effective when combined with low rather than high glycemic index (GI) diets [11] [12] [23] . Similarly, regular physical activity can reduce tissue resistance to insulin and thus increase sensitivity in diabetic patients [24] - [26] .

Among the prescribed MHDs, the prohibition of the consumption of sweet foods (biscuits, candies, chocolate, sugary drinks) was recommended to 96.1% of the patients. This result is in line with the international recommendation for the management of DM which prohibits the consumption fast sugar and sugary foods at diabetic patients given that the ability to regulate blood sugar is impaired and blood sugar peaks can be difficult to control, thus increasing the risk of long-term complications such as diabetic retinopathy, diabetic neuropathy, diabetic nephropathy and cardiovascular diseases [27] . The concept of glycemic index (GI) was prescribed in only 14 files out of 155 patient files, or 9.0% (P < 0.001). This finding suggests a lack of information among prescribers regarding a new food classification. It should be noted that the concept of glycemic index has replaced that of fast sugar/slow sugar, which classified sweet-tasting foods as having a rapid hyperglycemic effect [28] . However, some foods such as white rice, cassava and potato are known to have a high glycemic index, regardless of their taste [28] [29] .

Clinical recommendations in the diabetic diet indicate that carbohydrates should provide 50% - 60% of total energy intake (TEI) and preferably complex carbohydrates; the consumption of foods with a low glycemic index (GI) and glycemic load (GL) is to be favored; the intake of dietary fiber is 25 - 40 g/day, proteins 15% of TEI, lipid < 30% providing mono and polyunsaturated fatty acids, the consumption of fruits is strongly recommended; vegetables, nuts, fiber, whole grains, and unsaturated oils are to be favored. It is advisable to give three meals and two snacks, depending on the patient’s nutritional status [30] .

It should be noted that the concept of glycemic load, which takes into account both the glycemic index and the quantity of carbohydrates in the meal, was not found in any file. This concept has a great importance in dietary prescription, as a low or medium glycemic index diet is considered beneficial for the prevention and management of diabetes mellitus, coronary heart disease, and obesity [24] [31] . This dietary approach reduces insulin secretion and lowers blood lipid concentrations in patients with hypertriglyceridemia [13] [26] . In addition, the consumption of vegetables, fruits, and whole grains helps maintain blood glucose levels around normal values in diabetics due to their low or medium glycemic index, attributable to their high dietary fiber content.

The increasing incidence of type 2 diabetes mellitus (T2DM) could become a major health problem in Kisangani if strategies related to diet, physical activity, or both, which can prevent or delay T2DM and its complications in at-risk individuals, remain unknown [24] . Furthermore, it should be noted that other lifestyle and dietary measures, such as those related to sleep, stress, alcohol and tobacco, were also not present in the patients’ records, which highlights an additional aspect of the inadequacy of the lifestyle and dietary measures provided.