Effect of natural environmental changes on Hainan migratory population with hypertension in China and related plasma metabolism features

Abstract

The population-based study was aimed to probe the impact of environments on migratory population. A preliminary research on the duration of Hainan and the changes of blood pressure between Hainan and hometown was carried out among 262 migratory population. Fourteen pairs of long-term migrants and short-term migrants who migrated from Northeast China were further matched. The environmental exposure was estimated with satellite-based indices, including NDVI_1km,NDVI_500m, EVI_1km, EVI_500m, PM_2.5,PM₁₀, temperature and humidity. The plasma samples were collected for untargeted metabolomics and lipidomics. The nonlinear relation represented that the differential value of blood pressure changes without taking antihypertensive drugs gradient descended and then rose accompanying with Hainan duration, and decline turning point of systolic blood pressure and diastolic blood pressure were 4.43 and 6.28 month, respectively (P for nonlinear < 0.05). Five untargeted metabolites and ten lipids were identified as differential metabolites between long-term migrants and short-term migrants, and one enriched KEGG pathway, glycerolphospholipid, was identified. The plasma PC (36:5) and LysoPE (18:1) levels were significantly positively correlated with the green space exposure (P < 0.05) in the short-term migrants, and a negative correlation was observed between the plasma 4-carboxypyrazole level and temperature in the long-term migrants (P = 0.017). Our findings illustrated that moving to Hainan for about 4-6 months was more conducive to the improvement of blood pressure before taking antihypertensive drugs on hypertensive elderly, and the difference of plasma metabolomics between short-term and long-term migrants might be related to previous environmental exposure.

Keywords: Environmental factors; Hypertension; Metabolomics; Migratory elderly.

Fig. 1

Relationship between the duration of migratory population in Hainan and the changes of blood pressure before taking antihypertensive drugs between Hainan and hometown. (A) The D-value of SBP of migratory population that living in Hainan for 0–6 months was significantly lower than that of 12–18 and 18–24 month group, and (B) no significant difference on D-value of DBP was found between groups. **P < 0.01. (C) and (D) represent the nonlinear relation of Hainan duration and blood pressure changes, in which the corrected common covariates are age (continuous type), sex, education level, smoking and drinking.

Fig. 2

The distributions of blood pressure for short-term migrants (n = 89) and long-term migrants (n = 36). BP, blood pressure; SBP, systolic blood pressure; DBP, diastolic blood pressure.

Fig. 3

Correlation between two air pollutants (PM_2.5, PM₁₀), green space (EVI_1km, EVI_500m, NDVI_1km, NDVI_500m) and meteorological factors (TEMP and RH) in short-term migrants (A) and long-term migrants (B). *P < 0.1, **P < 0.05, ***P < 0.01.

Fig. 4

Comparative untargeted metabolomics and lipidomics analysis of plasma metabolites in short-term and long-term migrants. Untargeted metabolomics (A) and lipidomics (B) were performed to identify metabolic and lipidomic differences between short-term migrants and long-term migrants in PIM and NIM. Volcano plots illustrate the significantly altered metabolites in untargeted metabolomics (C) and lipidomics (D). The horizontal coordinates in the graph represent the fold change after logarithmic treatment, the closer the points to the sides, the larger the fold change; the vertical coordinates represent the adjusted P-value after logarithmic treatment, the higher the points the more significant. Downregulated metabolites are shown in blue, while upregulated metabolites are shown in red. Clustering heatmaps display distinct metabolic (E) and lipidomic (F) profiles between short-term migrants and long-term migrants. Heatmaps of untargeted metabolomics (G) and lipidomics (H) highlight group-specific differences (VIP > 2.5, P < 0.05). The color gradient reflects relative metabolite abundance, with red indicating high levels and blue indicating low levels. The horizontal axis represents sample groups, while the vertical axis lists the differentially abundant metabolites.

Fig. 5

Functional analysis of the metabolomics and lipids observed in short-term migrants and long-term migrants. KEGG enrichment scatter plot shows the biological processes in untargeted metabolites (A) or lipids (B) in short-term migrants and long-term migrants. The bubble size represents the range of the number of differential metabolites contained in each pathway, and the color from blue to red represents the Q value.

Fig. 6

Correlation analysis of environmental exposure and plasma metabolites. Correlation heatmap between 5 untargeted, 10 lipid important differential plasma metabolites and air pollutants (PM_2.5, PM₁₀), green space (EVI_1km, EVI_500m, NDVI_1km, NDVI_500m), meteorological factors (temperature and RH) in short-term migrants (A), long-term migrants (B). Different colors represent correlation level, *P < 0.1; **P < 0.05; ***P < 0.01.