The International Diabetes Federation (IDF) has pointed out that 60% of diabetics are from Asia (1). Moreover, 6 of the top 10 countries with the highest prevalence of diabetes are also in Asia. The 30 years results of Daqing’s diabetes prevention and control program in China showed that a healthy lifestyle has a long-term effect on diabetes prevention (2). In this article, 4 Asian countries were selected (China, Malaysia, Singapore, and Thailand) that have taken measures to prevent and control diabetes at the national level and also have the largest ethnically Chinese populations in Asia.
All data used in this article, i.e., the incidence of type 2 diabetes, were fetched from Global Burden of Disease (GBD) 2019 (3–4), and the standardized incidence rates (IRs, /100,000) was calculated based on the World Standard Population in 2019 provided by GBD 2019 (3). The growth rate, 5-year growth, and annual speed of increase between 1990 to 2019 were adopted as a metric to represent and evaluate the tendency of the standardized incidence rate along with time. Based on the results and analyses, evidence and guidance are provided for implementing and evaluating diabetes prevention and control.
Table 1 showed that there was a huge difference in the changes of the standardized incidence, e.g., growth rate and annual speed of increase, from 1990 to 2019 between the 4 Asian countries and the entire world. The global standardized incidence rate has increased by more than 40%. The increase of the incidence in China, with a growth rate of 6.26%, was significantly lower than that of the world overall. Although differing in the specific values, Malaysia, Singapore, and Thailand all have had a negative growth rate in incidence; particularly, the incidence growth rates were –50.02%, –86.88%, and –26.75%, respectively.
Nations Standardized incidence rate (/100,000) Changes of 2019 relative to 1990 1990 2019 Increment (/100,000) Growth rate (%) Annual speed of increase (%) Worldwide 184.55 259.94 75.39 40.85 1.82 China 8.63 9.17 0.54 6.26 0.32 Malaysia 26.57 13.28 –13.29 –50.02 –3.58 Singapore 18.22 2.39 –15.83 –86.88 –10.14 Thailand 24.90 18.24 –6.66 –26.75 –1.62
Table 1. The standardized incidence rate of type 2 diabetes and its changes worldwide, 1990–2019.
As shown in Table 2, like the former observation, the 5-year growth of the standardized incidence from 1990 to 2019 differed greatly among the 4 Asian countries. Specifically, China has an overall increasing trend, and its growth rate fluctuates greatly. A negative growth period could be observed in 1990–1995 and 2005–2015, during which its overall growth rate gradually slowed down, and there was no incremental change from 2015 to 2019. The annual speed of increase of Malaysia showed a rapid decrease on average, but it rebounded from 2015 to 2019 with an annual speed of increase of 3.69%. The annual speed of increase of Singapore was also continuously decreasing, where a rapid decline could be seen during 2005–2015, with a decreasing rate of 15% approximately. However, the speed of decline in Singapore was reduced to 0.82% during 2015–2019. In general, the decreasing rate of Singapore was quite higher than that of Malaysia from 1990 to 2019. The annual speed of increase of Thailand presented an overall downward tendency but with a non-negligible fluctuation: it maintained its decline from 1995 to 2010, but it rebounded during 2010–2015, with an annual speed of increase of 1.09%, and then maintained the annual speed of 1.03% from 2015 to 2019.
Year China Malaysia Singapore Thailand IRs ΔIRs ASI IRs ΔIRs ASI IRs ΔIRs ASI IRs ΔIRs ASI 1990 8.63 – – 26.57 – – 18.22 – – 24.90 – – 1995 8.43 –0.20 –0.47 25.44 –1.13 –0.87 12.82 –5.40 –6.79 26.73 1.83 1.43 2000 9.40 0.97 2.20 24.85 –0.59 –0.47 12.60 –0.22 –0.35 24.58 –2.15 –1.66 2005 10.65 1.25 2.53 20.98 –3.87 –3.33 11.59 –1.01 –1.66 18.64 –5.94 –5.38 2010 9.54 –1.11 –2.18 13.77 –7.21 –8.08 5.39 –6.20 –14.20 16.59 –2.05 –2.30 2015 9.17 –0.37 –0.79 11.49 –2.28 –3.56 2.47 –2.92 –14.45 17.51 0.92 1.09 2019* 9.17 0.00 0.00 13.28 1.79 3.69 2.39 –0.08 –0.82 18.24 0.73 1.03 Note: – means the growth and the annual speed of increase in 1990 cannot to be calculated.
Abbreviations: IRs=standardized incidence rate (1/100,000); ΔIRs=5-year growth of the standardized incidence (1/100,000); ASI=annual speed of increase over the last 5 years of the standardized incidence (%).
* The growth and the annual speed of increase in 2019 were computed based on the 4-year change with respect to 2015.
Table 2. The 5-year growth of the standardized incidence rate in China, Singapore, Malaysia, and Thailand, 1990–2019.
Figure 1A, 1B, and 1C showed that the standardized incidence rate of different age groups in the 4 Asian countries differed. The country that had the lowest standardized incidence rate for all 3 age groups (i.e., 15–44, 45–59, and above 60 years old) in 1990 was China, but Singapore had the lowest incidence in 2019. In summary, the age group of 15–44 years had the lowest standardized incidence rate of type 2 diabetes (<0.5/100,000), while the age group of above 60 years old had the highest one (<20/100,000).Figure 1. The standardized incidence rate of type 2 diabetes in different age groups in the 4 countries, 1990–2019. (A) 15–44 years; (B) 45–59 years; (C) 60 years. Note: There are 4 countries shown in Figure 1C; however, in order to highlight the main findings, only the lowest standardized incidence rate of type 2 diabetes in the age group of 60 years old and above in 1990 and 2019 (China and Singapore, respectively) were described in the corresponding text. Malaysia and Thailand were described in other parts.
According to the change from 1990 to 2019, for the age group of 15–44 years, Malaysia had the largest decline in the standardized incidence rate, with a decrease of 0.61/100,000, followed by Singapore, with a decrease of 0.58/100,000. China only had a decrease of 0.02/100,000, and Thailand even increased 0.17/100,000. For the age group of 45–59 years, Malaysia and Singapore attained the largest decline in the standardized incidence rate, with a decrease of 16.10/100,000 and 16.01/100,000, respectively, followed by Thailand, with a decrease of 10.58/100,000. China had the smallest decrease, i.e., 2.79/100,000; For the age group of above 60 years old, Singapore made the largest decline, followed by Malaysia and Thailand, with a decrease of 99.76/100,000, 81.11/100,000, and 35.01/100,000, respectively. China had a decline that was much lower than the above three countries, only a decrease of 7.47/100,000.
Therefore, this article conducted an analysis of the tendency of incidence with respect to different age groups. In terms of the age group of 45–59 years, as plotted in Figure 1B, the standardized incidence rate of type 2 diabetes in the 4 Asian countries showed overall decreases. Among the 4 countries, Singapore had an always-decreasing curve and had the most significant decline, but its downward tendency was relieved after the low point in 2013. Malaysia and Thailand both had a relatively large decline, which was always higher than that of China, but with fluctuations. The incidence for China remained relatively stable, just having a slight decline.
However, of the age group above 60 years old, as shown in Figure 1C, only Singapore showed an obvious downward trend. Malaysia had a significant rebound since 2013 after a decrease with fluctuation. After an early-stage reduction, the incidence rate of Thailand started to fluctuate and increase slightly in the high incidence rate range, i.e., roughly from 110/100,000 to 130/100,000. The incidence rate in China was lower than in Malaysia and Thailand, but the overall trend showed a slow rise.