Background: Diabetes mellitus occurs as a comorbid illness among people living with HIV and, in particular those on Highly Active Anti-retroviral therapies (HAART). Previous studies have documented the prevalence of diabetes mellitus among adults on HAART; however, there is lack of comprehensive estimation. Hence, this study was aimed to estimate the pooled prevalence and associated factors of diabetes mellitus among adults on HAART in Ethiopia. Methods: Primary studies were exhaustively searched using Cochrane, PubMed, Google Scholar, Scopus and Web of science databases until February 2021. Eligible studies were selected and critically appraised for quality using the Joanna Briggs Institute (JBI) quality appraisal checklist. The required data were extracted and exported to Stata version 16 for meta-analysis. The overall prevalence of diabetes mellitus among adults on HAART was estimated using a weighted inverse random effect model. Sensitivity and sub-group analysis were conducted for evidence of heterogeneity. Trim and fill analysis was performed after Egger's test and funnel plot were indicating the presence of publication bias. Results: A total of 17 studies with 6,052 subjects on HAART were included. The pooled prevalence of diabetes mellitus among patients on HAART was 16.04% [95% Confidence Interval (CI); 11.6, 20.92]. Abnormal High Density Lipoprotein Cholesterol (HDL-C) [Adjusted Odd Ratio (AOR) = 4.68, 95% CI; 2.54, 6.82], Body Mass Index (BMI) ≥ 25 kg/m2 [AOR = 7.41, 95% CI; 2.75, 12.08], ≥6 years ART [AOR = 8.14, 95% CI; 5.85, 30.43], hypertension [AOR = 3.29, 95% CI; 2.13, 4.45], age 35–44 years [AOR = 6.28; 95% CI; 4.20, 8.37, BMI ≥ 30 kg/m2 [AOR = 7.81, 95% CI; 4.97, 10.64], educational status above diploma [AOR = 6.42, 95% CI; 1.28, 11.57] and age 45–55 years [AOR = 4.46, 95% CI; 2.81, 6.10] were positively associated with diabetes mellitus comorbidity among adults on HAART. Conclusion: The higher prevalence of diabetes mellitus was observed for adults on HAART. HDL-C, duration of ART, hypertension, overweight, obesity, age and educational status of participants increases the prevalence of diabetes mellitus. The study highlights the importance of timely screening of HDL-C level, blood pressure and BMI for adults on HAART.
