Migration and diabetes incidence among Chinese adults in Canada, China, Hong Kong, and Taiwan: An international population-based comparative study from 2000 to 2017.

AIMS

We conducted an international population-based study comparing the incidence of young- (age 20-39 years) and usual- (age ≥ 40 years) onset diabetes among Chinese-Canadian immigrants; their source populations (mainland China, Hong Kong, Taiwan); and other Canadians.

METHODS

Using population-based data (2000-17; n = 3.4 million cases), we calculated incidence rates and incidence rate ratios comparing the average incidence for each cohort.

RESULTS

The average incidence of young-onset diabetes (YOD) among immigrants from China, Hong Kong, and Taiwan was 165.5, 121.0, and 78.4 per 100,000 person-years respectively. Immigrants from China and Hong Kong had higher YOD incidence than their source populations (RR China: 2.59, 2.44-2.74; Hong Kong: 1.64, 1.49-1.81), while immigrants from Taiwan had lower rates versus Taiwan (RR 0.63, 0.45-0.86). YOD incidence among immigrants from China increased sharply by 8.3% (3.3-13.6%) per year from 2011 onward-over twice the annual increase among non-Chinese Canadians. The average incidence rates of usual-onset diabetes among immigrants from China, Hong Kong, and Taiwan were higher than (RR 1.77, 1.73-1.81), similar to (0.98, 0.96-1.01), and lower than (0.36, 0.32-0.40) those in each source population respectively.

CONCLUSIONS

Diabetes incidence among Chinese migrants is unexpectedly heterogeneous, varying according age at migration, territory of origin, and the occurrence of diabetes in the source population.