Prediabetes Burden in Nigeria: A Systematic Review and Meta-Analysis

Prediabetes is a borderline glycemic status associated with both higher incidence of cardiovascular disease as well as higher risk of progression to diabetes. There is a rising burden of diabetes and prediabetes globally. This study aims to estimate the burden of prediabetes in Nigeria. Online searches of Google Scholar, PubMed, and Scopus were conducted and studies were selected based on predefined criteria. A total of 15 studies consisting of 14,206 individuals conducted between 2000 and 2019 were included in the meta-analysis with studies using American Diabetic Association (ADA) and World Health Organization (WHO) criteria pooled separately. The pooled prevalence of prediabetes in Nigeria was found to be 13.2% (95% CI: 5.6-23.2%, I-2 = 98.4%) using the ADA criteria and 10.4% (95% CI: 4.3-18.9%, I-2 = 99.2%) using the WHO criteria. According to the latest data by the United Nations, this translates to an estimated 15.8 and 12.5 million adult prediabetic individuals in Nigeria using the ADA and WHO criteria, respectively. The prevalence rates for women and men were similar at 12.1% (95% CI: 5-21%). The pooled prevalence rates for urban and rural settlements were also similar at 9% (95% CI: 2-22%). In conclusion, the prevalence of prediabetes in Nigeria was almost two times higher than the 7.3% estimate by the International Diabetes Federation in 2003. The similar rates of prediabetes between men and women and between urban and rural settlements points toward narrowing of cardiovascular risk burden between the two sexes and the two settlements. This represents higher future cardiovascular disease burden in the country further pressurizing the overstretched healthcare system.