Abstract:
Background: Type 2 diabetes mellitus (T2DM) accounts for over 90% of diabetes cases
worldwide and is associated with multiple complications. One of the primary complications of
T2DM is the development of hypertension (HTN). The co-existence of the two conditions elevates
the risk of serious complications and deaths. However, despite its high burden and impact, little is
known about the time to development of hypertension and its predictors among patients with type
2 diabetes mellitus in Ethiopia.
Objective: To assess time to development of hypertension and its predictors among type 2
diabetes mellitus patients attending Jimma Medical Center (JMC), southwest Ethiopia, 2025.
Methods: A facility-based retrospective cohort study was conducted at Jimma Medical Center
(JMC) among adult Type 2 Diabetes Mellitus (T2DM) patients who were normotensive at baseline
and enrolled for follow-up between January 1, 2020, and December 31, 2024. A total of 282 patient
records were selected using systematic random sampling technique. Data were collected using a
structured and pre-tested data extraction tool, and analyzed using STATA version 17. Descriptive
statistics were used to summarize patient characteristics. Kaplan–Meier survival curves were used
to estimate survival probabilities, and the log-rank test was applied to compare time-to-event
across predictor categories. Proportional hazards assumptions were assessed using Schoenfeld
residuals. Multivariable Cox proportional hazards regression was performed to identify
independent predictors of time to hypertension development, and a 95% confidence interval (CI)
was used to declare statistical significance in the final model.
Results: A total of 282 T2DM patients followed over 9,085 person-months of observation. Of
these, 74 developed hypertension resulting in an incidence rate of 8.15 per 1,000 person-months
(95% CI: 6.49–10.23). The median survival time to development of hypertension was 57 months.
Age ≥ 60 years (AHR = 3.63, 95% CI: 2.14–6.14), urban residence (AHR = 1.72, 95% CI: 1.01
2.96), poor drug adherence (AHR = 3.86, 95% CI: 2.08–6.18), and obesity (BMI ≥ 30 kg/m²)
(AHR = 3.13, 95% CI: 1.60–6.13) were found to be independent predictors significantly associated
with the time to development of hypertension among T2DM patients.
Conclusion and recommendation: Findings in this study indicated that the median time to
development of hypertension among type 2 diabetes mellitus patients was 57 months. Special
focus on older age, poor adherence, urban residence, and obesity is crucial to reduce hypertension
risk among T2DM patients.
