Epidemiology of Diabetes Mellitus in Oman: Results from two decades of research

Abstract

Objectives: This study aimed to describe the epidemiology of diabetes mellitus over the past two decades in Oman, particularly in terms of its prevalence and incidence. In addition, the study sought to estimate the future incidence of diabetes in Oman.

Methods: Three national and three regional surveys conducted between 1991 and 2010 were analysed to obtain the age-adjusted prevalence and undiagnosed proportion of type 2 diabetes mellitus (T2DM) among Omani subjects aged ≥20 years. Diabetes mellitus registers and published studies were used to determine incidence rates of both type 1 diabetes mellitus (T1DM) and T2DM in Oman. Linear regression was used to determine trends and projections for diabetes in 2050.

Results: The age-adjusted prevalence of T2DM in Oman varied from 10.4% to 21.1%, while the highest prevalence of impaired fasting glucose was found in males (35.1%). In comparison to men, higher incidence rates of T2DM were found in women (2.7 cases compared to 2.3 cases per 1,000 person-years, respectively). No significant trends were observed for the prevalence or incidence of T2DM in both genders. Undiagnosed T2DM was more common in men (range: 33-68%) than women (range: 27-53%). The results of this study show that by 2050, there will be an estimated 350,000 people with T2DM living in Oman (a 174% increase compared to estimates for 2015).

Conclusion: Health authorities need to prioritise diabetes prevention and control in order to prevent or delay long-term complications and avert a potential epidemic of diabetes in Oman.

Keywords: Diabetes Mellitus; Epidemiology; Incidence; Oman; Prevalence; Trends.

Figure 1:

Total age-adjusted prevalence of diabetes mellitus and impaired glucose tolerance/impaired fasting glucose among Omanis aged ≥20 years between 1991–2010 using data from six population-based national and regional surveys.– The World Health Organization diagnostic criteria for diabetes was used. IGT = impaired glucose tolerance; IFG = impaired fasting glycaemia; OGTT = oral glucose tolerance test; FPG = fasting plasma glucose.

Figure 2:

Trend in age-adjusted prevalence of diabetes mellitus among Omani adults aged ≥20 years between 1991–2010 using data from six population-based national and regional surveys.– Trends are presented according to gender, survey and method of test used. OGTT = oral glucose tolerance test; FPG = fasting plasma glucose.