Etiologic Types and Complications of Diabetes Mellitus in Newly Diagnosed Patients at Health Institutions in Bulawayo, Zimbabwe: Protocol for a Cross-Sectional and Prospective Observational Study.

Background: The prevalence of diabetes mellitus is increasing in sub-Saharan Africa. Data on the prevalence of diabetes in Zimbabwe are scarce, and the etiologic types of diabetes are not well characterized. Classification of diabetes in Zimbabwe relies on clinical criteria at the time of diagnosis, and more detailed phenotype data are lacking. Furthermore, the prevalence of complications at diagnosis of diabetes and the incidence of complications during follow-up are not well documented in Zimbabwe. Objective: The primary aim of this study is to characterize the etiological types of diabetes in adult and adolescent patients with newly diagnosed diabetes in Bulawayo, Zimbabwe. The secondary objectives are to determine the prevalence of chronic complications of diabetes among adult and adolescent patients with newly diagnosed diabetes and to determine the incidence and risk factors for the development of diabetes complications after a 2-year follow-up in patients with type 2 diabetes who are free of complications at baseline. Methods: This is a cross-sectional and prospective observational study. The cross-sectional (phase 1) study was conducted in patients presenting for the first time to the diabetes service at 2 referral hospitals and 2 diabetes clinics in Bulawayo, Zimbabwe. Data collected from consenting participants included demographic data, social and medical history, and clinical examination. Laboratory tests included serum urea, creatinine and electrolytes, liver function tests, lipids, plasma glucose, glycated hemoglobin, serum C-peptide, spot urine (dipstick, albumin, and creatinine), and β-cell antibodies (antiglutamic acid decarboxylase, anti-islet antigen, anti-insulin antibodies, anti-islet cell antibodies, and antizinc transporter 8 antibodies). All patients had retinal photography, a 12-lead electrocardiograph, and measurement of carotid intima-media thickness and arterial stiffness. Determination of the incidence of diabetes complications will be conducted through a 2-year follow-up (encompassing 6-mo review) of a subgroup of patients with type 2 diabetes and no diabetes complications at the time of enrollment. At each 6-month visit, in addition to all variables collected at baseline, data on diabetes management and drug therapy compliance will be obtained. Results: Data collection commenced in October 2021, with 323 participants recruited. Data analysis for phase 1 is ongoing. The study will be completed in October 2026. The results will describe the spectrum of diabetes and complications found at diagnosis (phase 1) and the incidence and risk factors associated with the development of complications of diabetes (phase 2). Conclusions: The study will provide data on etiologic types of diabetes in patients presenting to health facilities in urban centers in Bulawayo, Zimbabwe. In addition, data on diabetes complications at the time of diagnosis as well as incident complications over 2 years of follow-up will be compared with data from other studies. The data will be used to inform management strategies for patients diagnosed with diabetes in Zimbabwe.