Introduction

Diabetes mellitus (DM) is a chronic condition marked by inadequate insulin production or utilization, resulting in high blood glucose levels1. It can cause organ damage in the heart, blood vessels, eyes, kidneys, and nerves2. Poor glycemic control poses a major public health risk and significantly accelerates diabetic complications3,4. Diabetes complications are common, with 35% experiencing retinopathy and 12–55% facing end-stage renal disease. Diagnosed diabetes populations also have amputation rates 10–20 times higher than those without diabetes5.

A multinational study in 28 countries across Asia, Africa, Europe, and South America found high rates of diabetes complications: 27.2% had macrovascular complications, and 53.5% had microvascular complications6. In China, diabetic nephropathy affects approximately 10.7% of diabetics, while eye disease impacts about 14.8%7. In 2007, health spending on type 2 diabetes and its complications reached USD 339 billion, accounting for 22.3% of China's total health expenditure. Projections suggest this could almost double by 20308. In Sri Lanka, diabetic retinopathy, neuropathy, nephropathy, diabetic foot, and lower extremity amputation (LEA) had prevalence rates of 26.1%, 62.6%, 50.8%, 2.6%, and 1.3%, respectively9.

A systematic review in North Africa revealed varied prevalence rates of chronic diabetes complications: retinopathy (8.1–41.5%), albuminuria (21–22%), nephropathy (6.7–46.3%), and neuropathy (21.9–60%)10. In Ghana, 34.1% of diabetic individuals, develop complications11. Research in sub-Saharan Africa uncovered diabetes complications, such as 32% cataracts, 15% diabetic retinopathy, 13% impaired renal function, and 35% erectile dysfunction in men12. Furthermore, the overall economic burden of diabetes treatment in these countries is significantly high13. In Tanzania, a significant portion of individuals with diabetes experience complications: 12.0% have renal issues, 49.6% face eye problems, and 28.8% suffer from neurologic complications14.

Effective diabetes management aims for good glycemic control15,16 and preventing complications16, achievable through diverse strategies. Adopting lifestyle modifications such as weight management, dietary adjustments, quitting smoking, aerobic exercise, and strength training can decrease the risk of diabetes complications17. These habits also lower the risks of cardiovascular disease, thus reducing the burden of diabetes-related health issues and mortality18. Regular physical activity enhances insulin sensitivity, controls blood sugar, manages weight, and lowers diabetes complication risks19. Even modest levels of physical activity reduce the risk of diabetes complications20. Smoking21 and alcohol22 increase the risk of chronic complications in individuals with diabetes. Some studies found that higher body mass index (BMI) in diabetes patients increase the risk of chronic complications23,24,25, but one study showed no association between BMI and diabetes complications26.

Ethiopia faces a rising burden of non-communicable diseases (NCDs) like diabetes, ranking among the top four countries in sub-Saharan Africa with high adult diabetic populations. The prevalence is estimated at 2–3%, contributing to about 2% of all deaths27. Diabetes and its complications in Ethiopia significantly impact morbidity, mortality, and the economy28. Although few studies on chronic diabetes complications exist in the country29,30,31,32,33, but none have explored the impact of lifestyle factors on these complications. Understanding this connection is crucial for effective intervention strategies as these factors are considered modifiable risks. Therefore, this study aims to investigate the relationship between lifestyle factors and chronic diabetic complications at public health hospitals in Southwest Ethiopia.

Methods

Study design, setting, and period

A facility based cross-sectional study was conducted from 1st March to 30th September 2021 in Mizan-Tepi University Teaching Hospital (MTUTH) and Gebretsadik Shawo General Hospital (GSGH) in Southwest Ethiopia. MTUTH is found in southwest Bench Sheko Zone, Ethiopia serves communities across Bench Sheko, West Omo, Sheka, and Gambela regions. Initially established as Mizan Teferi Hospital in 1986, it became part of Mizan Tepi University in 2016, situated 585 km southwest of Addis Ababa. GSGH is situated in Bonga town, Kaffa Zone, approximately 449 km from Addis Ababa.

Populations

The study included all adult patients with diabetes mellitus receiving follow-up treatment at MTUTH and GSGH as the source population. The study population comprised adult patients meeting inclusion criteria and receiving follow-up treatment during the data collection period at both hospitals. Inclusion criteria encompassed adult diabetic patients aged ≥ 18 years on follow-up at MTUTH and GSGH. Exclusion criteria involved pregnant women, patients with known serious clinical diseases, critically ill patients and patients who did not provide consent to participate.

Sample size determination

The sample size was determined using a single population proportion formula (\({\text{n}} = \frac{{({\text{z}}_{{\frac{\alpha }{2}}} )^{2} {\text{p}}\left( {1 - {\text{p}}} \right)}}{{{\text{d}}^{2} }}\)), by considering the following assumptions; 95% confidence level, 5% margin of error and prevalence rate (p) of chronic complications of diabetes was 59.7%30. After adding a 10% contingency for non-response compensation, the final sample size was 407.

Sampling procedure

The total sample size was proportionally distributed between MTUTH (n = 163) and GSGH (n = 244), reflecting the diabetic patient population under follow-up at each hospital. Diabetes patients typically have monthly appointments for checkups and medication collection unless there is a disease-related emergency. Participants were chosen via systematic random sampling. The sampling interval (K = N/n) was calculated, and a random start (first participant) was selected through a lottery method from 1 to K. Subsequently, every K interval was selected until the desired sample size was reached. If selected participants didn't meet eligibility criteria or declined, replacements were chosen.

Study variables

The dependent variable was chronic complications of diabetes. The independent variables were socio-demographic factors (age, sex, education, marital status, place of residence, and religion), medical conditions (blood pressure, blood glucose, BMI, duration of diabetes, type of diabetes, family history of diabetes), and lifestyle factors (physical exercise, alcohol drinking, cigarette smoking, and khat chewing).

Operational definitions

Diabetic complications are confirmed by a physician if patients exhibit one or more chronic issues like neuropathy, nephropathy, retinopathy, impotence, peripheral sensory pains, or diabetic foot ulcers.

According to the WHO classification, BMI categories are underweight (≤ 18.5 kg/m2), normal weight (18.5–24.9 kg/ m2), overweight (25.0–29.9 kg/ m2), and obesity (≥ 30 kg/ m2)34.

Abdominal obesity was defined as a waist circumference (WC) exceeding 102 cm in men and 88 cm in women35,36.

Good glycemic control was defined as fasting blood glucose levels between 70 and 130 mg/dl across three consecutive visits; otherwise, it was considered poor glycemic control37.

Hypertension was characterized by systolic blood pressure of 140 mmHg or higher and/or diastolic blood pressure of 90 mmHg or higher12, measured with an automated device while seated.

Physical activity levels were assessed using the global physical activity questionnaire (GPAQ), which accounts for activity during work, travel, and recreational pursuits38.

Alcohol intake was assessed using the standard drink concept and the Nordic Alcohol Consumption Inventory (NACI) through a quantity-frequency method. Individuals consuming at least one unit (≥ 12 g) per week were categorized as drinkers, while others were considered non-drinkers39.

Khat chewer was defined as a person who chews khat at least once within a week; otherwise, they were considered nonchewer40,41.

Cigarette smoking: Participants were categorized as smokers if they had smoked at least 100 cigarettes in their lifetime; otherwise, they were considered nonsmokers42.

Data collection tools, procedures, and quality control

Interviewers used a pre-tested questionnaire, developed from relevant literature30,31, for data collection. The questionnaire covered socio-demographic details, medical history, and lifestyle factors. It underwent translation from English to Amharic and back, with consistency checked by fluent speakers. Face validity was confirmed by a diabetes research expert. Reliability, assessed by Cronbach’s alpha (0.83), indicated strong consistency. A pretest on 5% of the sample in Chena hospital preceded data collection. We reviewed patient medical records for essential medical information, such as diabetes type, duration of diabetes, physician-diagnosed chronic complications, and laboratory results including fasting blood sugar levels utilized to determine glycemic control status over three consecutive visits. We conducted a physical examination to gather data on height, weight, waist circumference and blood pressure. BMI was calculated as weight in kilograms divided by height in meters. Waist circumference was measured using a flexible plastic metric tape accurate to the nearest 0.1 cm. The measurement was taken midway between the anterior superior iliac crest and the lower rib border, with the individual standing. The tape was applied snugly after a deep inhalation and a light expiration, without pinching the skin35. Venous blood samples (5 ml) were collected in plain tubes with serum separator gel and centrifuged at 3000 revolutions per minute for 10 min at room temperature to analyze kidney function tests (urea, creatinine) and glucose levels. Data collectors received training in data collection techniques, and their work was closely supervised by experienced health professionals (two supervisors per hospital) to ensure completeness, accuracy, and precision daily.

Statistical analysis

The data was entered into Epi-Data version 3.1 and then imported into Statistical Package for the Social Sciences (SPSS) version 25 for analysis. We assessed the dataset for outliers and adherence to assumptions. Categorical variables were summarized by frequency and percentages, while continuous variables were described using mean and standard deviation. Bivariate logistic regression analysis was conducted for all independent variables, with those having a p-value less than 0.25 considered for inclusion in the multivariable model. Multivariable logistic regression analysis was then performed, and the level of significance declared at p < 0.05. The strength of association was measured using odds ratios at a 95% confidence level. The Hosmer–Lemeshow goodness-of-fit test suggested a good fit between the model and the data (p = 0.249). Results were presented in figures and tables.

Ethical approval and consent to participate

Ethical approval (Approval Number: MTUERC/08/2021) was obtained from the Mizan-Tepi University Ethical Review Committee (MTU-ERC) before data collection. Participants were informed of the study's objectives, their right to refuse participation, and the confidentiality of their information. Written informed consent was obtained from all participants. For those unable to read and write, informed consent was obtained from their legal guardians. All procedures followed relevant guidelines and regulations.

Results

Socio-demographic characteristics

Out of the 407 planned samples, 389 participants successfully participated in the study, resulting in a response rate of 95.6%. Among these participants, 240 (61.7%) were male. The mean (± SD) age of the participants was 45.6 (± 17.6) years, with 167 (42.9%) falling within the age range of 18–40 years and 146 (37.5%) in the 41–60 years age range. In terms of marital status, more than two-thirds (69.7%) of the participants were married. Additionally, the majority (60.9%) of participants resided in urban areas. More than half of the participants (56.3%) were self-employed, and 163 participants (41.9%) identified as belonging to the Bench ethnic group (Table 1).

Table 1 Socio-demographic characteristics of the study participants at MTUTH and GSGH in southwest Ethiopia.
Full size table

Lifestyle characteristics and medical profiles

Two hundred thirty-five (60.4%) of the participants were physically inactive. One hundred eighteen (30.3%) and 52 (13.4%) of the participants were alcohol drinkers and cigarette smokers respectively (Fig. 1). The average (± SD) serum glucose level was 142 mg/dl (± 38.4), and for serum creatinine, it was 0.72 mg/dl (± 0.26). The mean (± SD) duration of diabetes was 6.01 (± 4.68) years. One hundred twenty (30.8%) reported a family history of diabetes mellitus. Most participants (67.4%) had type II diabetes, while 182 (46.8%) were hypertensive. Nearly one-third (64%) of the participants had poor glycemic control, and 169 (43.5%) had abdominal obesity (Table 2).

Figure 1
figure 1

Lifestyle characteristics of the study participants at MTUTH and GSGH in southwest Ethiopia.

Full size image
Table 2 Medical profiles of the study participants at MTUH and GSGH in southwest Ethiopia.
Full size table

Chronic complications of diabetes

The study revealed a 32.1% prevalence of chronic complications of diabetes, with 13.4% having chronic kidney disease, 8.0% experiencing visual disturbances, and 16.7% suffering from peripheral sensory pain (Fig. 2).

Figure 2
figure 2

Chronic complications of diabetes among the study participants at MTUTH and GSGH in southwest Ethiopia.

Full size image

Factors associated with chronic complications of diabetes

After adjusting for confounding variables, certain factors showed significant associations with chronic complications of diabetes. These included age (41–60 years [AOR = 1.77; 95% CI 1.01, 3.15] and > 60 years [AOR = 2.18; 95% CI 1.20, 4.33]), duration of diabetes (> 6 years [AOR = 2.90; 95% CI 1.74, 4.85]), alcohol consumption [AOR = 2.30; 95% CI 1.33, 3.98], physical inactivity [AOR = 2.43; 95% CI 1.38, 4.27], and BMI (underweight [AOR = 7.66; 95% CI 1.68, 34.8] and obese [AOR = 3.53; 95% CI 1.84, 10.5]) (Table 3).

Table 3 Factors associated with chronic complications of diabetes among the study participants at MTUTH and GSGH in southwest Ethiopia.
Full size table

Discussion

The study found that 67.4% of participants had type II diabetes, aligning with previous research at Jimma University Specialized Hospital in Southwest Ethiopia43. Furthermore, 46.8% of subjects were hypertensive, like findings in a study conducted in Tanzania14. Our research found a 32.1% prevalence of chronic complications of diabetes mellitus among participants, consistent with studies conducted in Ethiopia44 and internationally6. The study revealed significant associations between chronic complications of diabetes and various factors such as age, alcohol consumption, physical activity, duration of diabetes, and BMI.

Diabetic patients aged 41–60 and > 60 years had 1.77- and 2.18-times higher odds of chronic complications compared to the reference age group. This corresponds with results from a study conducted in Ghana45, suggesting that with advancing age, the risk of developing diabetes complications increases. The heightened risk observed among older individuals might stem from factors like age-related weight gain and declining physical activity levels46.

Alcohol consumption also proved to be a significant factor, with alcohol drinkers having 2.30 times higher odds of chronic complications compared to non-drinkers. This discovery aligns with a study carried out elsewhere47. This connection may be attributed to alcohol's influence on the accumulation of specific acids, which could worsen medical complications associated with diabetes48.

Regular physical activity helps prevent diabetes complications by improving body weight control49. Our study revealed that physically inactive individuals had 2.43 times higher odds of developing diabetes-related chronic complications than their active counterparts. This corresponds with Wang et al.'s research50, indicating that inadequate physical activity heightens the risk of diabetes complications and metabolic syndrome. Physical activity is vital for glycemic control by reducing insulin resistance, boosting GLUT-4 production, reducing visceral fat, and improving pancreatic β-cell function50.

Our findings showed that patients with diabetes for over six years had 2.90 times higher odds of developing chronic complications compared to those with a shorter duration of six years or less. This corresponds with a study in Mettu, Ethiopia51, indicating that patients with diabetes for 10 years or more have a higher likelihood of developing chronic complications compared to those with a shorter duration of illness. This association may be attributed to the long-term effects of hyperglycemia on cellular signaling in human metabolic disorders52.

Diabetic patients who were underweight and obese had 7.66- and 3.53-times higher odds of chronic complications compared to those with a normal BMI. This finding aligns with research conducted by Martins et al.53. The heightened risk of complications among underweight patients may stem from accelerated loss of pancreatic beta-cells and poorer glycemic control, whereas for obese patients, it could relate to insulin resistance and β-cell dysfunction54,55.

Conclusion

The study highlights the substantial impact of diabetes complications on patients in two hospital catchment areas, reflecting the problem in the study area. Lifestyle factors were strongly linked to chronic diabetes complications. With these factors being modifiable, preventive measures are crucial. Implementing intensive health education programs in hospitals and promoting prevention through community service projects emphasizing lifestyle modification for preventing chronic diabetes complications should be prioritized.