Ethnic differences in the prevalence of high homocysteine levels among low-income rural Kazakh and Uyghur adults in far western China and its implications for preventive public health

Homocysteine (Hcy) is a relevant biomarker of vascular disease: serum Hcy concentrations will increase the risk of systolic hypertension, whereas hyperhomocysteinemia (HHcy) has a synergistic effect with hypertension and increases the risk of cardiovascular disease. However, information has primarily been gathered from high-income and urban settings, and little is known regarding low-income rural settings. This study focused on a low-income rural and nomadic minority residing in far western China. Hcy levels were tested, and the prevalences of HHcy and H-type hypertension were investigated in this population. This study used a stratified cluster random sampling method, selecting 2,180 individuals as subjects from Kazakh and Uyghur inhabitants (≥25 years old) of 18 villages in Xinjiang, China, which is approximately 4407 km from the capital, Beijing. Hcy levels were determined using a double reagent enzymatic cycling method. HHcy (Hcy > 10 μmol/L) was defined by the criteria of the American Heart Association. The Kazakh geometrical mean of Hcy was 13.34 μmol/L, and the Uyghur mean was 13.75 μmol/L; the mean values were higher in males than in females of both ethnicities (15.99 μmol/L vs. 11.63 μmol/L; 15.71 μmol/L vs. 11.91 μmol/L, respectively, p < 0.01). The serum levels of Hcy increased with increasing age in both ethnicities, and except for Kazakh individuals >65 years old, Hcy serum levels were higher in males than in females in all age groups of both ethnicities, with a p value less than 0.01. The Kazakh prevalence of HHcy was 80.0%, and the Uyghur prevalence was 78.2%; the male prevalence was higher than that in females for both ethnicities (93.5% vs. 69.6%; 90.8% vs. 64.6%, respectively, p < 0.05). Among the Kazakh, the prevalence of hypertension was 35.1%, and the prevalence was higher in males than in females (44.3% vs. 28.1%, p < 0.001); 87.6% of the Kazakh individuals had H-type hypertension, and the prevalence was higher in males than in females (95.0% vs. 80.0%, p < 0.05). In Uyghur, the prevalence of hypertension was 30.6%, and the prevalence was higher in males than in females (37.9% vs. 22.8%, p < 0.001); 88.0% of the Uyghur individuals had H-type hypertension, and the prevalence was higher in males than in females (93.9% vs. 79.1%, p < 0.05). HHcy was found to be common among the Kazakh and Uyghur. The prevalences of HHcy and H-type hypertension were high among both ethnicities and differed depending on gender and age. Community interventi