Association between Dietary Patterns and Metabolic Syndrome and Modification Effect of Altitude: A Cohort Study of Tibetan Adults in China.

Little is known about the longitudinal association between dietary patterns (DPs) and metabolic disorders in people living at high altitude areas, such as Tibetans. We constructed the first open cohort, with 1832 Tibetans, and collected data in 2018 and in 2022. The metabolic syndrome (MetS) prevalence was 30.1% (32.3% in men and 28.3% in women). Three different DPs were identified: modern DP (pulses, poultry, offal, and processed meat), urban DP (vegetables, refined grain, beef/mutton, and eggs), and pastoral DP (Tibetan cheese, tsamba, butter/milk tea, and desserts). Participants within the third tertile of the urban DP had a 3.42-fold (95% CI 1.65-7.10) higher risk of MetS than those with the first tertile. Modern DP was positively associated with elevated blood pressure (BP) and elevated triglycerides (TAG), while it was inversely associated with low HDL-C. The urban DP was associated with a higher risk of low HDL-C, but a lower risk of impaired fasting blood glucose (FBG). The pastoral DP was a risk factor for impaired FBG, but protective for central obesity and elevated BP. Associations of modern DP with elevated BP, and pastoral DP with low HDL-C, were modified by altitude. In conclusion, among Tibetan adults, DPs were associated with MetS and its components, and the associations were modified by altitude among Tibetans.

Maternal urinary metal(loid)s and risk of preterm birth: A cohort study in the Tibetan Plateau.

Maternal metal(loid)s exposure has been related to preterm birth (PTB), but the results are still inconclusive. Previous studies have mainly discussed the harmful metal(loid)s, neglecting beneficial ones. We examined the association of maternal metal(loid)s with PTB and gestational age (GA) in a birth cohort from the Tibetan Plateau. We measured 29 metal(loid)s in urine samples from 1081 pregnant women in the third trimester. Information regarding demographics, socioeconomic status, diet, medication, and lifestyle was collected through standardized interviews. The associations of single metal(loid)s with PTB or GA were evaluated using a generalized linear mixed-effects model or linear mixed-effects model. Elastic net and Bayesian kernel machine regressions were used to explore the joint associations. Magnesium (Mg), Copper (Cu), and Tin (Sn) were the main "harmful" metal(loid)s positively and negatively associated with PTB or GA, respectively. Mg was the dominant "harmful" metal(loid)s associated with PTB in a J-shape. A one-fold increase in Mg was associated with a 38% increased risk of PTB [OR (95% CI) = 1.38 (1.15, 1.65), PFDR＜0.05] and 0.17 weeks shortening of GA [ß (95% CI) = -0.25 (-0.35, -0.14), PFDR＜0.05]. Cesium (Cs), rubidium (Rb), and Molybdenum (Mo) were the main "beneficial" metals. Cs dominated the "beneficial" associations and was negatively associated with PTB in a linear manner. A one-fold increase in Cs was associated with a 67% decreased risk of PTB [OR (95% CI) = 0.43 (0.27, 0.67), PFDR＜0.05] and 0.24 weeks of prolonged GA [ß (95% CI) = 0.35 (0.13, 0.56), PFDR＜0.05]. Ethnicity and living altitude modified the association of Mg and Cu with PTB or GA. In conclusion, Maternal urinary metal(loid)s were bi-directionally associated with PTB in a population in the Tibetan Plateau. Mg and Cs were the dominant "harmful" and "beneficial" metal(loid)s, respectively.

Disparities of obesity and non-communicable disease burden between the Tibetan Plateau and developed megacities in China.

Background: Non-communicable diseases (NCDs) including risk factors, e.g., obesity, are the major causes of preventable deaths in China, yet NCD disparities in China remain under-studied. Objective: This study aimed to compare the determinants and burden of NCDs within four selected provinces in mainland China: the least developed Qinghai-Tibet Plateau group (PG, Tibetan Autonomous Region [TAR] and Qinghai Province) and most developed megacity group (MCG, Shanghai, and Beijing). Methods: Studies, reports, and other official sources with comparable data for NCD burden and related determinants for the four provinces were searched. Geographic, demographic, socioeconomic, and dietary characteristics and selected health indicators (e.g., life expectancy) were extracted from the China Statistical Yearbook and China Health Statistics Yearbook. Data on NCD burdens were extracted from the National Chronic Disease and Risk Factor Surveillance Study and other nationally representative studies. Results: The overall NCD mortality rates and prevalence of metabolic risk factors including obesity, hypertension, and diabetes in mainland China have increased in the past 20 years, and this trend is expected to continue. The PG had the highest level of standardized mortality rates (SMRs) on NCDs (711.6-896.1/100,000, 6th/6-level); the MCG had the lowest (290.6-389.6/100,000, 1st/6-level) in mainland China. The gaps in SMRs were particularly high with regard to chronic respiratory diseases (PG 6th/6-level, MCG 1st/6-level) and cardiovascular diseases (6th/6 and 4th/6 in TAR and Qinghai; 1st/6-level and 2nd/6-level in Shanghai and Beijing). In contrast, the prevalence rates of obesity, hypertension, and diabetes were generally higher or comparable in MCG compared to PG. Diabetes prevalence was particularly high in MCG (5th/5-level, 13.36-14.35%) and low in PG (1st/5-level, 6.20-10.39%). However, awareness, treatment, and control of hypertension were poor in PG. Additionally, PG had much lower and severely inadequate intakes of vegetables, fruits, and dairy products, with additional indicators of lower socioeconomic status (education, income, etc.,) compared with MCG. Conclusion: Evidence showed large disparities in NCD burden in China's provinces. Socioeconomic disparity and dietary determinants are probably the reasons. Integrated policies and actions are needed.