Background: According to previous researches, there were several risk factors of type 2 diabetes, including age, overweight or obesity, hypertension, dyslipidemia etc. However, it is not clear whether there are specific diabetes related risk factors in high altitude areas due to the unique low oxygen and low atmospheric pressure environment.
Methods: This study is a population-based, cross-sectional epidemiological survey. The permanent Tibetan residents in Lhasa and Shigatse were enrolled in this study, including 1 urban area (10 communities) and 7 rural areas (48 villages). OGTT, HbA1c, blood lipid and blood cell counts were measured in all the subjects. Diabetes was diagnosed according to the WHO criteria. The diagnostic standard of high altitude polycythemia (HAPC) is the universal Qinghai standard (male hemoglobin ≥ 210g/L, female ≥ 190g/L).
Results: A total of 1401 subjects were enrolled in this study. The average age was 44.3 ± 15.0 years old, 33.3% were male. The prevalence of diabetes in the study population was 3.6% (5.8% among men and 2.6% among women, p=0.003; 4.4% in rural vs. 2.4% in urban areas, p=0.033). The prevalence of diabetes increased with increasing age (1.9%, 4.7%, and 7.1% among persons who were 18 to 44, 45 to 59, and ≥60 years of age, respectively) and with increasing BMI (0, 2.3%, 4.7%, and 11.3% among persons with a BMI of <18.5, 18.5 to 23.9, 24.0 to 27.9, and ≥28.0, respectively). The prevalence of HAPC was 6.4% (6.2% among men and 6.5% among women, p=0.453). The prevalence of diabetes was significantly higher in HAPC group than in non HAPC group (11.2% vs. 3.1%, P<0.001). After quartile grouping of Hb, the prevalence of diabetes was 1.6%, 1.8%, 4.5% and 6.3% respectively (p=0.001). After adjusting for gender, age, BMI, hypertension, hyperuricemia and hypercholesterolemia, logistic regression analysis indicated that HAPC was an independent risk factor for diabetes (or = 3.514, 95% CI 1.606-7.689, P = 0.002).
Conclusion: HAPC is an independent risk factor of type 2 diabetes in Tibet, China.
Q. Ren: None. X. Lv: None. L. Zhou: None. Y. Luo: None. L. Yang: None. L. Ji: None.
Science and Technology Project of Tibet Autonomous Region (CGZH2017000085); National Key Research and Development Program (2016YFC1304901)