Mauritius Documents Drop in Type 2 Diabetes Prevalence

Population Surveys Confirm a Sustained Downturn in Cases

Mauritius is the first nation to document a population-level drop in type 2 diabetes using the two-hour oral glucose tolerance test (OGTT). Researchers presented the findings at the European Association for the Study of Diabetes (EASD) Annual Meeting in Milan and published the full dataset in The Lancet Diabetes & Endocrinology. Overall prevalence across the country fell from 23.3 percent in 2009 to 19.9 percent in 2021.

The shift marks a change in trajectory for the Indian Ocean island nation of 1.2 million people. Adult type 2 diabetes rates had risen steadily between 1987 and 2009, climbing 61 percent in men and 56 percent in women. Between 2009 and 2021, prevalence dropped by 11 percent in men and 16 percent in women, reversing two decades of upward trends.

Oral Glucose Tolerance Tests Reveal Trends Other Screens Miss

The World Health Organization (WHO) considers the two-hour oral glucose tolerance test the standard method for diagnosing diabetes and intermediate hyperglycemia. Most national surveys rely instead on fasting plasma glucose or glycated hemoglobin (HbA1c) because blood draws after an overnight fast are simpler to administer. Those faster screening options can miss asymptomatic cases that show up only after a standardized glucose challenge.

Mauritius is the only country that has tracked adult metabolic health through systematic oral glucose tolerance tests across several decades. Participants in the surveys fast for 8 to 10 hours, take a baseline blood draw, drink 75 grams of glucose, and provide blood samples at one and two hours. Patients remain seated and avoid food, exercise, and smoking until the final sample is complete.

Survey Timeline Tracks Three Decades of Metabolic Change

Seven cross-sectional surveys conducted between 1987 and 2021 document how the disease burden shifted across the island. The Ministry of Health and Wellness carried out the testing with academic teams from Finland, Australia, the United Kingdom, and Sweden. Lead investigators included Paul Zimmet of Monash University, Jaakko Tuomilehto of the University of Helsinki, and Sir George Alberti.

The longitudinal data record the rise and subsequent retreat of adult diabetes over 34 years:

• 1987: 14.7 percent overall prevalence (14.0 percent in women, 15.3 percent in men)
• 1992: 17.3 percent overall prevalence (16.6 percent in women, 18.0 percent in men)
• 1998: 20.2 percent overall prevalence (19.3 percent in women, 21.1 percent in men)
• 2004: 18.6 percent overall prevalence (18.3 percent in women, 18.7 percent in men)
• 2009: 23.3 percent overall prevalence (22.0 percent in women, 24.7 percent in men)
• 2015: 23.1 percent overall prevalence (23.7 percent in women, 22.6 percent in men)
• 2021: 19.9 percent overall prevalence (18.1 percent in women, 21.7 percent in men)

Clinical Screening Takeaways for Metabolic Assessment

Standard laboratory testing in primary care clinics often relies on fasting glucose or glycated hemoglobin rather than a timed tolerance test. Individuals investigating persistent symptoms or borderline laboratory values can ask a doctor whether an oral glucose tolerance test is appropriate. The two-hour test provides a direct measure of how muscle, liver, and pancreatic tissue clear glucose from circulation under an acute load.

Population-wide reductions do not remove individual risk factors like genetics, physical inactivity, or diet. Patients managing blood sugar concerns should discuss their individual screening results with a licensed healthcare provider before making treatment decisions.

Research Limitations and Monitoring Caveats

Cross-sectional population surveys provide periodic snapshots rather than tracking the same individuals continuously over time. The 19.9 percent figure recorded in 2021 remains high, affecting roughly one in five adults across Mauritius. The authors noted that prevention policies and free public care supported the progress, but long-term monitoring is required to confirm whether the decline continues in future survey cycles.

Readers monitoring their blood sugar can discuss with their clinician whether adding a two-hour oral glucose tolerance test provides diagnostic clarity beyond standard fasting blood tests.