Prevalence of Type 2 Diabetes Mellitus in the General Population of Saudi Arabia, 2000–2020: A Systematic Review and Meta-Analysis of Observational Studies

BACKGROUND: The prevalence of type 2 diabetes mellitus (T2DM) has increased worldwide, including in Saudi Arabia. OBJECTIVE: To systematically review the available literature and assess the pooled prevalence of T2DM in Saudi Arabia between 2000 and 2020. METHODS: Observational studies that reported quantitative estimates of the prevalence of T2DM as their main outcome, included the general population of Saudi Arabia, and were published between 2000–2020 and in English were retrieved using three electronic databases (namely, CINAHL, Medline via PubMed, and Web of Science). Retrieved studies were screened, and relevant data were extracted. The Joanna Briggs Institute Critical Appraisal guideline was used to assess the methodological quality of included studies. A random-effects model was used to estimate the prevalence of T2DM. RESULTS: Twenty-three studies were included in the systematic review, of which 19 were included in the meta-analysis (total pooled population: 258,283). The overall pooled prevalence of T2DM in Saudi Arabia was 16.4% (95% CI: 11.6–17.5). However, there was heterogeneity in the results of the studies [I(2) = 99.31%, P < 0.0001] and the summary values varied from 3.18% (95% CI: 1.46–5.95) to 94.34% (95% CI: 89.53–97.38). Although the prevalence of T2DM by age varied across studies, in most studies, it was higher among the older age groups. In addition, the prevalence of diabetes widely varied across the different geographical regions of Saudi Arabia. CONCLUSIONS: This is the first meta-analysis that determined the pooled prevalence of T2DM in Saudi Arabia, and it revealed a high prevalence over the past two decades. However, owing to data collection inconsistencies in the identified studies, neither the modifiable (such as obesity, educational status, emotional support, etc.) nor the non-modifiable (such as gender and age) risk factors of T2DM could be determined, thereby indicating the need for a nationally collective effort in determining these factors.