Risk Factors for Diabetic Complications among Diabetic Patients, Chirumanzu District, Zimbabwe, 2011

Research Article

Austin J Public Health Epidemiol. 2015; 2(2): 1021.

Risk Factors for Diabetic Complications among Diabetic Patients, Chirumanzu District, Zimbabwe, 2011

Nyika Ponesai¹, Chimusoro Anderson², Tshimanga Mufuta¹, Gombe Notion¹, Takundwa Lucia¹ and Bangure Donewell¹*

¹Department of Community Medicine, University of Zimbabwe, Zimbabwe

²Provincial Medical Directorate, University of Midlands Province, Zimbabwe

*Corresponding author: Donewell B, Department of Community Medicine, University of Zimbabwe, Harare, Zimbabwe

Received: March 13, 2015; Accepted: September 17, 2015; Published: September 25, 2015


Introduction: Diabetic complications are largely a result of elevated blood sugar and are responsible for most deaths due to diabetes mellitus. Strict blood sugar control, achieved through adherence to treatment and lifestyle modifications such as physical activity and eating a healthy diet, is critical in the reduction of the incidence of these complications. This study assessed the factors associated with diabetic complications in both outpatients and hospitalized patients.

Methods: We conducted a 1:1 unmatched case-control study among diabetic patients attending hospitals in Chirumanzu District, Midlands Province, Zimbabwe. Structured interviewer administered questionnaires were used to collect data on socio-demographic, knowledge and practices, treatment and health services risk factors. Univariate descriptive statistics such as proportions, means and medians were calculated. Bivariate and stratified analyses were done before stepwise logistic regression to identify independent risk factors. Data were analyzed using Epi-INFO

Results: We enrolled 68 cases and 68 controls with a median ages of 51.5(Q1=43, Q3=61) and 52.5(Q1=43.5, Q3= 60.5) respectively. The majority were females 86 (63.3%). The major diabetic complication was severe hyperglycemia 44/68 (64.7%). Socio-demographic factors associated with diabetic complications were: Being unmarried [OR=3.68, 95%CI(1.70-8.07)], being widowed [OR=2.93,CI(1.14-7.68)], Having attained at most primary education [OR=2.83, 95%CI(1.29-6.25)] and urbanized residence [OR=2.48; 95%CI,(1.17-5.28)]. A significant practice factor was: Eating sugar containing diet[OR=3.9, 95%CI(1.86-8.18)].Treatment risk factors were: Insulin therapy [OR=3.83, 95%CI(1.78-8.34)], Missing doses [OR=6.63, 95%CI(3.08-14.29)] and co-morbidity with hypertension [OR=4.10, 95%CI(2.01-8.39)]. Distance from hospital >5km [3.97, 95%CI 1.77-9.00)] and failure to get drugs [OR=3.12, 95%CI (1.54-6.32)] were significant health services factors associated with complications. Health education [OR=0.274, 95%CI (0.134-0.56)], being already on treatment [OR=0.36, 95 %CI (0.165-0.779)] and having a treatment supporter [OR=0.24, 95%CI (0.115-0.49)] were protective factors. Independent risk factors were: Insulin therapy (p-value0.018), missed treatment doses (p-value=0.0113), co-morbidity with hypertension (p-value=0.0019) and failing to get drugs (p-value<0.001).

Conclusion: The major socio-demographic and treatment related risk factors are largely functions of the patients’ knowledge and practices which can be mitigated by simple and inexpensive interventions. The health services factors found are a reflection of the coverage and efficiency of health services in the district which need to be addressed at national level. We therefore recommend the inclusion of health education in the treatment package for diabetic patients, community health education and the decentralization of diabetes care and treatment to rural health centres.

Keywords: Diabetes; Complications; Blood sugar; Patients; Risk


The World Health Organization (WHO) estimates that more than 220 million people worldwide have diabetes, 80% of which live in low and middle income countries. Most people with diabetes in low and middle income countries are middle-aged (45-64), not elderly (65+). This has serious adverse socio-economic effects as this is a productive age group [1].

According to WHO, diabetes causes about 5% of all deaths globally each year. In 2004, an estimated 3.4 million people died from consequences of high blood sugar. More than 80% of diabetes deaths occur in low and middle-income countries. It is projected that diabetes deaths are likely to increase by more than 50% in the next 10 years, and to double between 2005 and 2030 without urgent action [1]. In Africa, an estimated seven million Africans (out of 1billion) suffer from this disease which is now ranked as the fourth main cause of death in most developing countries [2].

Diabetes mellitus is a chronic condition that can lead to complications over time. The long-term complications of diabetes are caused by the effect of high blood sugar levels on blood vessels. Although complications of diabetes are mostly consequences of hyperglycemia, hypoglycemia, if not recognized and corrected early is fatal [1].

Diabetic complications can be prevented (or delayed) by tight blood sugar control achieved through medical treatment and simple lifestyle changes.

Chirumanzu District is located in Midlands Province of central Zimbabwe. Zimbabwe is a southern African country bordering with South Africa to the south, Botswana to the south west, and Namibia to the west, Zambia to the north and Mozambique to the east. The health care system in Zimbabwe is premised on the primary health care approach, with clinics (primary level) as the port of entry into the system. Clinics refer cases that they cannot manage to district hospitals (secondary level), district hospitals to provincial hospitals (tertiary level) and finally to central hospitals (quaternary level).

Information obtained from trends analysis of non-communicable disease (NCDs) in Midlands Province for the period 2000-2009 showed a general increase in these conditions. Surveillance data has also shown that NCDs remain a significant cause of morbidity and mortality contributing between 15 and 20% of all out patients department visits.

In Chirumanzu District, for the year 2010, diabetes mellitus was the leading cause of death, the second major cause of admission and the second major cause of out-patients visits among the NCDs, second to hypertension in both cases.

We hypothesized that there are socio-demographic factors, knowledge and practice factors, treatment factors and health services related factors associated with the high incidence of diabetic complications leading to admission and deaths among diabetic patients in Chirumanzu District, which if prevented or reduced, could reduce morbidity and mortality due to diabetes. We therefore investigated the risk factors for diabetic complications among both inpatients and outpatients in Chirumanzu District.


A 1:1 unmatched case control study among diabetes mellitus inpatients and outpatients in Chirumanzu District was conducted. A case was any person, 18 years and above, presenting to any of the 3 (three) hospitals in Chirumanzu District between 01 July 2010 and 30 June 2011 inclusive, with diabetes mellitus, previously diagnosed or newly diagnosed, and had severe hyperglycaemia, hypoglycaemia, diabetic foot or nephropathy. A control was any person, 18 years and above, presenting to any of the 3 (three) hospitals in Chirumanzu District between 01 July 2010 and 30 June 2011 inclusive, with diabetes mellitus, previously diagnosed or newly diagnosed and did not have severe hyperglycemia, hypoglycemia, diabetic foot or nephropathy.

A case of severe hyperglycemia was any patient with a fasting blood sugar greater than 7.0mmol/L or a random (casual) blood sugar greater than 11.1mmol/L, requiring admission for blood sugar control as determined by the clinician in charge. A case of hypoglycemia was any patient previously diagnosed with diabetes mellitus and put on treatment who had a blood sugar reading less than 3.5mmol/L.2 Diabetic foot was any patient with a chronic foot ulcer and/or gangrene attributed to diabetes mellitus by the clinician in charge and nephropathy was any patient previously diagnosed or newly diagnosed of diabetes mellitus who had persistent proteinuria (proteinuria on 2 occasions, at least 2weeks apart) and/or a serum creatinine greater than 132mmol/L. [3].

None consenting patients, those who had no documented clinical and/or laboratory evidence of complications of interest and could not be evaluated for the complications of interest during data collection were excluded from the study. Those who had not completed a month’s treatment by 30 June 2011 were also excluded

The Statcalc function of Epi-info was used to calculate the minimum required sample size at 95% confidence level, 80% power and a case to control ratio of 1:1. Findings from a study done by Flores Rivera AR, in 1998, were used where the odds ratio for lack of outpatients diabetes education was 3.2 and the proportion of exposure in the control group was 15% [4].

A minimum sample size of 150 participants (75 cases and 75 controls) was required. Diabetic status was confirmed by checking medical records. A pretested interviewer administered questionnaire was used to collect data on socio-demographic factors, knowledge and practices of participants on diabetes, treatment factors and health services related factors. Hospital records were reviewed to determine the types of complications, type of treatment, co-morbidity with hypertension and measurements of interest and also to verify drug supplies.

Anthropometric measurements of weight and height were done using a calibrated digital scale and a standard height meter respectively and the Body Mass Index (BMI) of each participant was calculated using the formula: BMI = weight (Kg) /Height2 (m). Study participants whose renal function had not been tested had urine dipstick tests done and recorded.

Epi-info version 3.3.2 was used to analyze quantitative data to generate means, proportions and frequencies. Bivariate analyses to calculate odds ratios, 95% confidence intervals and p-values were also computed using Epi-info to test for associations between risk factor variables (exposure variables) and the development of diabetic complications (outcome variable). Stratified analysis was done to assess for possible effect modification and confounding. Chi square test was used to determine the significance of differing odds ratios. Logistic regression analysis was done to control for confounding and determine independent risk factors for developing diabetic complications. Variables with p-values less than 0.25 were included in the regression model. Qualitative data were analyzed manually.

Permission to carry out the study was obtained from the Health Studies Office, the Provincial Medical Director Midlands and the District Medical Officer for Chirumanzu District. Informed written consent was obtained from all study participants. Health education was given to study participants after each interview. Ethical approval for the study protocol was obtained from the Medical Research Council of Zimbabwe.


Out of the required sample of 150 (75cases and 75 controls) a total of 136 (90.1%) eligible study participants `managed to take part in the study. This consisted of 68 cases and 68 controls. Of the 75 cases we intended to interview, 5 (five) could not be located during the time of data collection and 2 (two) were too sick to participate in the study and these were excluded. Sixty-eight controls were therefore interviewed to maintain the 1:1 case: control ratio.

Out of the 136 successful study participants, 68 (50%) were on insulin, 46 (67,6%) cases and 24 (35.3%) controls, 64 (47.1) were on oral hypoglycemic tablets and 4 (2.9%) were on dietary control of diabetes. Of the 68 patients on insulin, 55 (80.9%) had been changed from oral hypoglycaemics to insulin.