Prevalence of abnormal glucose metabolism among adults attending an outpatient department at a tertiary referral hospital in Swaziland: a cross-sectional study

BACKGROUND: The exact prevalence of type 2 diabetes mellitus (T2DM) and pre-diabetes in Swaziland remains unknown. Estimates suggest that the prevalence rate of type 2 diabetes mellitus is between 2.5 and 6.0% in Swaziland. The disparity in these estimates is due to a lack of quality data but the prevalence of diabetes is increasing in Swaziland. This study estimates the prevalence of type 2 diabetes mellitus and pre-diabetes among patients in a tertiary hospital in Manzini, Swaziland. METHODS: A cross-sectional observational survey was used to estimate the crude and age-adjusted prevalence rates of diabetes and pre-diabetes (impaired fasting glucose (IFG) and impaired glucose tolerance (IGT)) in the Manzini regional referral hospital of Swaziland. Diabetes was defined as a fasting blood glucose (FBG) ≥ 7.0 mmol/L (126 mg/dL) and pre-diabetes was defined as an FBG of 6.1–6.9 mmol/L (110–125 mg/dL) and an FBG < 7.0 mmol/L (< 126 mg/dL), respectively for IFG and IGT. A random sample of 385 participants was used. Data analysis was done using SPSS version 26 and the level of statistical significance was set at α < 0.05. RESULTS: The crude prevalence of type 2 diabetes mellitus and pre-diabetes was 7.3% [95% CI 4.9–10.3] and 6.5% [95% CI 4.2–9.4], respectively, with clear gender differences in the prevalence of diabetes (men 1.6% vs women 5.7%, p = 0.001). On the other hand, significantly more men (3.6%) had pre-diabetes than women (2.9%) (p = 0.004). The overall age-adjusted prevalence rates of type 2 diabetes mellitus and pre-diabetes were 3.9 and 3.8%, respectively. Among the diabetic group, 3 (10.7%) had known T2DM, whereas 25 (89.3%) were newly diagnosed during the study. Advancing age, gender, raised blood pressure, abnormal body mass index, and wealth index were significant risk factors for T2DM or prediabetes. CONCLUSION: The prevalence of type 2 diabetes mellitus among adult outpatients in the Raleigh Fitkin Memorial hospital was higher than previously reported in the health facility in Manzini; suggesting the need for routine T2DM screening at outpatient departments.