Prevalence of Diabetes in the 2009 Influenza A (H1N1) and the Middle East Respiratory Syndrome Coronavirus: A Systematic Review and Meta-Analysis

Abstract

Over the past two decades a number of severe acute respiratory infection outbreaks such as the 2009 influenza A (H1N1) and the Middle East respiratory syndrome coronavirus (MERS-CoV) have emerged and presented a considerable global public health threat. Epidemiologic evidence suggests that diabetic subjects are more susceptible to these conditions. However, the prevalence of diabetes in H1N1 and MERS-CoV has not been systematically described. The aim of this study is to conduct a systematic review and meta-analysis of published reports documenting the prevalence of diabetes in H1N1 and MERS-CoV and compare its frequency in the two viral conditions. Meta-analysis for the proportions of subjects with diabetes was carried out in 29 studies for H1N1 (n=92,948) and 9 for MERS-CoV (n=308). Average age of H1N1 patients (36.2±6.0 years) was significantly younger than that of subjects with MERS-CoV (54.3±7.4 years, P<0.05). Compared to MERS-CoV patients, subjects with H1N1 exhibited 3-fold lower frequency of cardiovascular diseases and 2- and 4-fold higher prevalence of obesity and immunosuppression, respectively. The overall prevalence of diabetes in H1N1 was 14.6% (95% CI: 12.3-17.0%; P<0.001), a 3.6-fold lower than in MERS-CoV (54.4%; 95% CI: 29.4-79.5; P<0.001). The prevalence of diabetes among H1N1 cases from Asia and North America was ~two-fold higher than those from South America and Europe. The prevalence of diabetes in MERS-CoV cases is higher than in H1N1. Regional comparisons suggest that an etiologic role of diabetes in MERS-CoV may exist distinctive from that in H1N1.

Keywords: 2009 influenza A (H1N1); Diabetes mellitus; Systematic Review; the Middle East respiratory syndrome coronavirus (MERS-CoV).

Figure 1.

Systematic literature review process. The flow diagram describes the systematic review of literature on the contribution of diabetes to severe H1N1 and MERS-CoV. A total of 38 unique studies were identified (29 studies for H1N1 and 9 for MERS-CoV from an initial 342 examined titles).

Figure 2.

Funnel plot for systematic review on the prevalence of diabetes in H1N1 and MERS-CoV studies. The logit event rate for prevalence (horizontal axis) is presented against the standard error (SE) of the log of logit event rate (vertical axis) for H1N1 (a) and MERS-CoV (b) studies. The SE inversely corresponds to the study size. Asymmetry of the plot can indicate publication bias. Open circles indicate the individual studies.

Figure 3.

Meta-analysis for the proportion of diabetes in H1N1 cases. Weights are calculated from binary random-effects model analysis. Values represent proportion of diabetic cases in the H1N1 patients and 95% CI. Heterogeneity analysis was carried out using Q test, the among studies variation (I index) and in between-study variance in the random-effects model (τ²).

Figure 4.

Meta-analysis for the proportion of diabetes in MERS-CoV cases. Weights are calculated from binary random-effects model analysis. Values represent proportion of diabetic cases in the MERS-CoV patients and 95% CI. Heterogeneity analysis was carried out using Q test, the among studies variation (I index) and in between-study variance in the random-effects model (τ²).