A serial 4-year cross-sectional study of dyslipidemia on Pamirs Plateau, the roof of the world.

BACKGROUND

Dyslipidemia is a major cardiovascular risk factor; however, disease patterns-particularly lipid profiles-remain understudied in high-altitude populations. On the Pamirs Plateau (> 4000 m), no relevant epidemiological studies have been conducted to date. This study investigates the disease patterns in this region, with an emphasis on dyslipidemia epidemiology.

METHODS

We conducted a serial cross-sectional study (2021-2024) using annual health examination data from Tashkurgan County, Pamirs Plateau. Adults aged ≥ 18 years residing ≥ 1 year were included. We first examined the overall disease patterns, with a focus on dyslipidemia. Age-standardized prevalence was calculated and stratified by sex and ethnicity. Subsequently, lipid profile distributions and temporal trends were analyzed. To place these findings in a global context, LDL-C levels were compared with populations from plains and other high-altitude regions. Finally, potential risk factors were identified using multivariate logistic regression and machine learning models.

RESULTS

Among a representative subset (24.37%) of the Pamirs Plateau population, dyslipidemia was the most prevalent condition, followed by hypertension, sinus bradycardia, and fatty liver. The prevalence of dyslipidemia ranged from 25.24% to 37.64%. LDL-C levels were lower than those in plains and other high-altitude regions. Ethnic disparities were evident: the minority population (predominantly Tajik) maintained stable, favorable lipid profiles across ages, while non-minorities exhibited pronounced age-related fluctuations. Age 70 emerged as a potential inflection point at which sex-related differences in LDL-C levels reversed. Male, non-minority, older age, diabetes, frequent alcohol consumption, and higher education were significantly associated with dyslipidemia. Unexpectedly, improved living conditions (range hood use [OR: 1.839, 95% CI: 1.673-2.021], natural gas use [OR: 1.273, 95% CI: 1.152-1.406], tap water access [OR: 1.315, 95% CI: 1.204-1.436]) were linked to a higher risk, a "modernization paradox". Additionally, distinct temporal fluctuations were observed: LDL-C levels sharply declined in 2022 before rebounding, coinciding with the COVID-19 lockdown period.

CONCLUSIONS

This first comprehensive analysis from "the roof of the world" reveals unique lipid patterns, including low LDL-C levels, pandemic-era fluctuations, ethnic disparities, unique age-sex patterns, and a paradoxical association between improved living conditions and increased dyslipidemia risk. These insights should inform context-specific lipid management strategies for this and similar vulnerable high-altitude populations globally.