CHRONIC KIDNEY DISEASE INCIDENCE AND ITS ASSOCIATED RISK FACTORS IN THE EASTERN MEDITERRANEAN REGION: A SYSTEMATIC REVIEW AND META-ANALYSIS

Abstract

In the last three decades, chronic kidney disease (CKD) has become the leading cause of morbidity and risen to become the world’s third fastest-growing cause of death, posing substantial societal, economic, and healthcare challenges. Yet, the epidemiological profile of new CKD cases in the Eastern Mediterranean Region (EMR) remains scarce, uncharted, and often fragmented across individual country-level studies with discrepancies in data on CKD burden. The factors influencing the natural course of CKD are complex and heterogeneous. However, the global data highlights age, diabetes, and hypertension as prime drivers, but EMR-specific factors are obscured by fragmented surveillance and scarce incidence reporting. This gap delays timely detection, early targeted preventive intervention, and evidence-based solution frameworks in policymaking in a region. Accordingly, the primary aim of this systematic review and meta-analysis is to quantify CKD incidence and synthesize its principal risk factors across EMR populations. Methods and Materials: Adhering to PRISMA 2020 guidelines and its search extension. Five bibliographic electronic databases (MEDLINE, EMBASE, CINAHL, PsycINFO, and EBSCO) were searched without language or date limits. Eligible studies were peer-reviewed observational studies (cohort and case-control) reporting CKD incidence and associated risk factors in any of the 22 EMR countries. Appraised methodological quality using the Newcastle–Ottawa Scale. The analytic approach integrates three main steps: (1) descriptive numeric summary, (2) narrative synthesis, and (3) meta-analysis. Incidence data were standardized to “cases per person-year”. Log-transformed incidence rates were pooled in a single-arm random-effects meta-analysis (REML), with inverse-variance weighting, and re-expressed as cases per 1,000 person-years. Cochran’s Q and I² were used to assess heterogeneity, while publication bias was assessed with funnel plots and Egger’s test (≥ 10 studies). Subgroup/meta-regression explored country-level and methodological moderators; sensitivity analyses (leave-one-out and fixed-effect models) tested robustness. Results: Nineteen EMR studies (total n = 66,494 participants) met inclusion criteria, and eleven of those had sufficient data for single-arm pooling. The overall pooled CKD incidence was 25 per 1,000 person-years (95% CI 19-32), with significant heterogeneity (Q = 1910.6, df = 10, P < 0.001; I² = 99.6 %). Country-specific estimates ranged from 23.1 in Iran to 41.0 in Tunisia per 1,000 person-years. However, meta-regression revealed that country, follow-up length, and sample size explained small variance. Narrative synthesis identified specific drivers of the disease incidence that are interconnected and overlapping, including age, female sex, low educational or marital status, diabetes, hypertension, general or central adiposity, dyslipidemia, high uric acid, and renal pathologies as the most consistently reported risk factors. Lifestyle contributors (tobacco use, high‑salt/processed diets, and inadequate or extreme physical activity) were also prominent, whereas coffee, lignan‑rich foods, and moderate exercise play a protective role. Furthermore, nephrotoxic medications and short endogenous estrogen exposure further elevated CKD risk. Conclusions: The overall pooled estimate rate is 25 incidents per 1,000 person-years. This incidence is comparable to the global average. Yet, certain nations within the region show significantly higher rates. The CKD incidence in the area is mainly driven by overlapping cardiometabolic risk factors (e.g., diabetes, hypertension), sociodemographic shifts, unhealthy lifestyle patterns (e.g., obesity and dietary risks), environmental exposure (e.g., pollution), and iatrogenic-related conditions (herbal medications). Calling for an urgent integrated solution approach combined with specific prevention strategies, such as early identification of high-risk groups, diabetes and hypertension control, emphasis on healthy lifestyle promotion, and constraint on nephrotoxic drug and herbal use. Improving surveillance systems and harmonized diagnostic criteria will be essential for tracking progress towards Sustainable Development Goal targets on non‑communicable diseases.